TEXAS INSTRUMENTS bq2060A Technical data

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bq2060A

SBS v1.1-Compliant Gas Gauge IC

Features

Provides accurate measurement

of available charge in NiCd, NiMH, Li-Ion, and lead-acid batteries

Supports SBS Smart Battery

Data Specification v1.1 Supports the 2-wire SMBus v1.1

interface with PEC or 1-wire HDQ16

Reports individual cell voltages

Monitors and provides control to

charge and discharge FETs in Li-Ion protection circuit

Provides 15-bit resolution for

voltage, temperature, and current measurements

Measures charge flow using a

V-to-F converter with offset of less than 16µV after calibration

Consumes less than 0.5mW operating

Drives a 4- or 5-segment LED display for remaining capacity indication

28-pin 150-mil SSOP

General Description

The bq2060A SBS-Compliant Gas Gauge IC for battery pack or in-system installation maintains an accurate record of available charge in rechargeable batteries. The bq2060A monitors capacity and other critical battery parameters for NiCd, NiMH, Li-Ion, and lead-acid chemistries. The bq2060A uses a V-to-F converter with automatic offset error correction for charge and discharge counting. For voltage, temperature, and current reporting, the bq2060A uses an A-to-D converter. The onboard ADC also monitors individual cell voltages in a Li-Ion battery pack and allows the bq2060A to generate control sig nals that may be used in conjunction with a pack supervisor to enhance pack safety.

The bq2060A supports the smart battery data (SBData) commands and charge-control functions. It communicates data using the system management bus (SMBus) 2-wire protocol or the Benchmarq 1-wire HDQ16 protocol. The data available include the battery’s remaining capacity, temperature, voltage, current, and remain ing run-time predictions. The

Pin Connections Pin Names

bq2060A provides LED drivers and a push-button input to depict remaining battery capacity from full to empty in 20% or 25% increments witha4or 5-segment display.

The bq2060A works with an external EEPROM. The EEPROM stores the configuration information for the bq2060A, such as the battery’s chem istry, self-discharge rate, rate com pensation factors, measurement cali bration, and design voltage and ca pacity. The bq2060A uses the pro grammable self-discharge rate and other compensation factors stored in the EEPROM to accurately adjust re maining capacity for use and standby conditions based on time, rate, and

temperature. The bq2060A also auto matically calibrates or learns the true battery capacity in the course of a discharge cycle from near-full to near-emptylevels.

The REG output regulates the operating voltage for the bq2060A from the battery cell stack using an external JFET .

HDQ16

ESDA

SLUS500A–OCTOBER 2001–REVISED MAY 2002

ESCL

2 3

RBI

REG

OUT

DISP

LED

28-Pin 150-mil SSOP

SMBC

SMBD

VCELL

25 24 23 22 21 20 19 18 17 16 15

VCELL VCELL SR SR SRC TS THON CVON CFC DFC

28PN2060.eps

3 2

1 1 2

HDQ16 Serial communication

ESCL Serial memory clock ESDA Serial memory data and

RBI Register backup input REG Regulator output V V V DISP LED

LED

input/output

address

EEPROM supply output

OUT

Supply voltage

Ground

Display control input

–

LED displaysegmentoutputs

1 5

DFC Discharge FET control CFC Charge FET control VON Cell voltage divider

control THON Thermistorbias control TS Thermistor voltage input SRC Current sense input

–

SR SR

VCELL VCELL

SMBD SMBus data SMBC SMBus clock

Charge-flow sense resistor

inputs

–

Single-cell voltage inputs

1 4

bq2060A

Pin Descriptions

HDQ16

ESCL

ESDA Serial memory data and address

RBI

REG Regulator output

OUT

DISP

LED1– LED

Serial communication input/output

Open-drain bidirectional communications port

Serial memoryclock

Output to clock the data transfer between the bq2060A and the external nonvolatile configuration memory

Bidirectional pin used to transfer address and data to and from the bq2060A and the external nonvolatile configuration memory

Input that provides backup potential to the bq2060A registers during periods of low operating voltage. RBI accepts a storage capacitor or a battery input.

Output to control an n-JFET for V lation to the bq2060A from the battery potential

Supply output

Output that supplies power to the external EEPROM configuration memory

Supply voltage input Ground Display control input

Input that controls the LED drivers

–LED

LED

LED display segment outputs

Outputs that each may drive an external LED

regu-

DFC

CFC

CVON

THON

SRC

–

VCELL VCELL

SMBD

SMBC

Discharge FET control output

Output to control the discharge FET in the Li-Ion pack protection circuitry

Charge FET control output

Output to control the charge FET in the Li-Ion pack protection circuitry

Cell voltage divider control output

Output control for external FETs to connect the cells to the external voltage dividers during cell voltage measurements

Thermistor bias control output

Output control for external FETs to connect the thermistor bias resistor during a tempera ture measurement

Thermistor voltage input

Input connection for a thermistor to monitor temperature

Current sense voltageinput

Input to monitor instantaneous current

Sense resistor inputs

Input connections for a small value sense resistor to monitor the battery charge and discharge current flow

Single-cell voltage inputs

–

1 4

Inputs that monitor the series element cell voltages

SMBus data

Open-drain bidirectional pin used to trans fer address and data to and from the bq2060A

SMBus clock

Open drain bidirectional pin used to clock the data transfer to and from the bq2060A

bq2060A

Functional Description

General Operation

The bq2060A determines battery capacity by monitoring the amount of charge input or removed from a recharge able battery. In addition to measuring charge and dis charge, the bq2060A measures battery voltage, tempera ture, and current, estimates battery self-discharge, and monitors the battery for low-voltage thresholds. The bq2060A measures charge and discharge activity by monitoring the voltage across a small-value series sense resistor between the battery’s negative terminal and the negative terminal of the battery pack. The available battery charge is determined by monitoring this voltage and correcting the measurement for environmental and operating conditions.

Figure 1 shows a typical bq2060A-based battery-pack application. The circuit consists of the LED display, voltage and temperature measurement networks, EEPROM connections, a serial port, and the sense resis tor. The EEPROM stores basic battery-pack configuration information and measurement-calibration values. The EEPROM must be programmed properly for bq2060A operation. Table 9 shows the EEPROM memory map and outlines the programmable functions available in the bq2060A.

The bq2060A accepts an NTC thermistor (Semitec 103AT) for temperature measurement. The bq2060A uses the thermistor temperature to monitor battery-pack temperature, detect a battery full-charge con dition, and compensate for self-discharge and charge/dis charge battery efficiencies.

Measurements

The bq2060A uses a fully differential, dynamically bal anced voltage-to-frequency converter (VFC) for charge measurement and a sigma delta analog-to-digital con verter (ADC) for battery voltage, current, and tempera ture measurement.

Voltage, current, and temperature measurements are made every 2–2.5 seconds, depending on the bq2060A operating mode. Maximum times occur with compen sated EDV, mWh mode, and maximum allowable dis charge rate. Any AtRate computations requested or scheduled (every 20 seconds) may add up to 0.5 seconds to the time interval.

Charge and Discharge Counting

The VFC measures the charge and discharge flow of the battery by monitoring a small-value sense resistor between the SR

and SR2pins as shown in Figure 1.

The VFC measures bipolar signals up to 250mV. The bq2060A detects charge activity when V V

is positive and discharge activity when VSR=V

SR1

–V integrates the signal over time using an internal counter. The fundamental rate of the counter is

6.25µVh.

Offset Calibration

The bq2060A provides an auto-calibration feature to can cel the voltage offset error across SR mum charge measurement accuracy. The calibration rou tine is initiated by issuing a command to ManufacturerAccess(). The bq2060A is capable of auto matic offset calibration down to 6.25µV.Offset cancellation resolution is less than 1µV.

is negative. The bq2060A continuously

SR1

SR=VSR2

and SR2for maxi

Digital Filter

The bq2060A does not measure charge or discharge counts below the digital filter threshold. The digital fil

ter threshold is programmed in the EEPROM and should be set sufficiently high to prevent false signal detection with no charge or discharge flowing through the sense resistor.

Voltage

While monitoring SR1and SR2for charge and discharge currents, the bq2060A monitors the battery-pack potential and the individual cell voltages through the VCELL

voltage and reports the result in Voltage(). The bq2060A

can also measure the voltage of up to four series ele ments in a battery pack. The individual cell voltages are stored in the optional Manufacturer Function area.

The VCELL cells using precision resistors, as shown in Figure 1. The

maximum input for VCELL

spect to V

set so that the voltages at the inputs do not exceed the

1.25V limit under all operating conditions. Also, the di vider ratios on VCELL VCELL the battery, the CVON output may used to connect the

divider to the cells only during measurement period.

CVON is high impedance for 250ms (12.5% duty cycle) when the cells are measured, and driven low otherwise. (See Table1.)

The SRC input of the bq2060A measures battery charge and discharge current. The SRC ADC input converts the current signal from the series sense resistor and stores the result in Current(). The full-scale input range to SBC is limited to ±250mV as shown in Table2.

–VCELL4pins. The bq2060Ameasures the pack

–VCELL4inputs are divided down from the

–VCELL4is 1.25V with re

. The voltage dividers for the inputs must be

–VCELL4. To reduce current consumption from

–VCELL2must be half of that of

–

SR2

bq2060A

Figure 1. Battery Pack Application Diagram–LED Display and Series Cell Monitoring

bq2060A

Table 1. Example VCELL1–VCELL4Divider

and Input Range

Voltage Input

VCELL

Voltage Division

Ratio

16 20.0 16 20.0

8 10.0 8 10.0

Full-Scale Input

(V)

Table 2. SRC Input Range

Sense Resistor (W) Full-Scale Input

0.02

0.03

0.05

0.10

(A)

±12.5

±8.3 ±5.0 ±2.5

Current

Temperature

The TS input of the bq2060A in conjunction with an NTC thermistor measures the battery temperature as shown in Figure 1. The bq2060Areports temperature in Temperature(). THON may be used to connect the bias source to the thermistor when the bq2060A samples the TS input. THON is high impedance for 60ms when the temperature is measured, and driven low otherwise.

Gas Gauge Operation

General

The operational overview in Figure 2 illustrates the gas gauge operation of the bq2060A. Table 3 describes the bq2060Aregisters.

The bq2060A accumulates a measure of charge and discharge currents and estimates self-discharge of the

Figure 2. bq2060A Operational Overview

bq2060A

Table 3. bq2060A Register Functions

Function

ManufacturerAccess 0x00 0x00 read/write n/a

RemainingCapacityAlarm 0x01 0x01 read/write mAh, 10mWh

RemainingTimeAlarm 0x02 0x02 read/write minutes

BatteryMode 0x03 0x03 read/write n/a

AtRate 0x04 0x04 read/write mA, 10mW

AtRateTimeToFull 0x05 0x05 read minutes

AtRateTimeToEmpty 0x06 0x06 read minutes

AtRateOK 0x07 0x07 read Boolean

Temperature 0x08 0x08 read 0.1°K

Voltage 0x09 0x09 read mV

Current 0x0a 0x0a read mA

AverageCurrent 0x0b 0x0b read mA

MaxError 0x0c 0x0c read percent

RelativeStateOfCharge 0x0d 0x0d read percent

AbsoluteStateOfCharge 0x0e 0x0e read percent

RemainingCapacity 0x0f 0x0f read mAh, 10mWh

FullChargeCapacity 0x10 0x10 read mAh, 10mWh

RunTimeToEmpty 0x11 0x11 read minutes

AverageTimeToEmpty 0x12 0x12 read minutes

AverageTimeToFull 0x13 0x13 read minutes

ChargingCurrent 0x14 0x14 read mA

ChargingVoltage 0x15 0x15 read mV

Battery Status 0x16 0x16 read n/a

CycleCount 0x17 0x17 read cycles

DesignCapacity 0x18 0x18 read mAh, 10mWh

DesignVoltage 0x19 0x19 read mV

SpecificationInfo 0x1a 0x1a read n/a

ManufactureDate 0x1b 0x1b read n/a

SerialNumber 0x1c 0x1c read integer

Reserved 0x1d–0x1f 0x1d - 0x1f - -

ManufacturerName 0x20 0x20–0x25 read string

DeviceName 0x21 0x28–0x2b read string

DeviceChemistry 0x22 0x30–0x32 read string

ManufacturerData 0x23 0x38–0x3b read string

Pack Status 0x2f (LSB) 0x2f (LSB) read/write n/a

Pack Configuration 0x2f (MSB) 0x2f (MSB) read/write n/a

VCELL4 0x3c 0x3c read/write mV VCELL3 0x3d 0x3d read/write mV VCELL2 0x3e 0x3e read/write mV VCELL1 0x3f 0x3f read/write mV

Command Code SMBus

SMBus HDQ16

Access Units

bq2060A

battery. The bq2060A compensates the charge current measurement for temperature and state-of-charge of the battery. It also adjusts the self-discharge estimation based on temperature.

The main counter RemainingCapacity() (RM) represents the available capacity or energy in the battery at any given time. The bq2060A adjusts RM for charge, self-discharge, and leakage compensation factors. The information in the RM register is accessible through the communications ports and is also represented through the LED display.

The FullChargeCapacity() (FCC) register represents the last measured full discharge of the battery. It is used as the battery’s full-charge reference for relative capacity indication. The bq2060A updates FCC when the battery undergoes a qualified discharge from nearly full to a low battery level. FCC is accessible through the serial com munications ports.

The Discharge Count Register (DCR) is a non-accessible register that only tracks discharge of the battery. The bq2060A uses the DCR register to update the FCC regis ter if the battery undergoes a qualified discharge from nearly full to a low battery level. In this way, the bq2060A learns the true discharge capacity of the battery under system use conditions.

Main Gas Gauge Registers

RemainingCapacity() (RM)

RM represents the remaining capacity in the battery. The bq2060A computes RM in either mAh or 10mWh depending on the selected mode.

On initialization, the bq2060A sets RM to 0. RM counts up during charge to a maximum value of FCC and down during discharge and self-discharge to 0. In addition to charge and self-discharge compensation, the bq2060A calibrates RM at three low-battery-voltage thresholds, EDV2, EDV1, and EDV0 and three programmable midrange thresholds VOC25, VOC50, and VOC75. This provides a voltage-based calibration to the RM counter.

DesignCapacity() (DC)

The DC is the user-specified battery full capacity. It is calculated from Pack Capacity EE 0x3a–0x3b and is rep resented in mAh or 10mWh. It also represents the full-battery reference for the absolute display mode.

FullChargeCapacity() (FCC)

FCC is the last measured discharge capacity of the bat tery. It is represented in either mAh or 10mWh depend ing on the selected mode. On initialization, the bq2060A sets FCC to the value stored in Last Measured Dis charge EE 0x38–0x39. During subsequent discharges, the bq2060A updates FCC with the last measured dis

charge capacity of the battery. The last measured dis charge of the battery is based on the value in the DCR register after a qualified discharge occurs. Once up dated, the bq2060A writes the new FCC value to EEPROM in mAh to Last Measured Discharge. FCC represents the full battery reference for the relative dis play mode and relative state of charge calculations.

Discharge Count Register (DCR)

The DCR register counts up during discharge, independ ent of RM. DCR can continue to count even after RM has counted down to 0. Prior to RM = 0, discharge activity, light discharge estimation and self-discharge increment DCR. After RM = 0, only discharge activity increments DCR. The bq2060A initializes DCR to FCC – RM when RM is within twice the programmed value in Near Full EE 0x55. The DCR initial value of FCC – RM is reduced

by FCC/128 if SC = 0 (bit 2 in Control Mode) and is not reduced if SC = 1. DCR stops counting when the battery voltage reaches the EDV2 threshold on discharge.

Capacity Learning (FCC Update) and Qualified

Discharge

The bq2060A updates FCC with an amount based on the value in DCR if a qualified discharge occurs. The new value for FCC equals the DCR value plus the programmable nearly full and low battery levels, according to the following equation:

FCC(new) DCR(final) DCR(initial) measured dischar

(FCC Battery Low%+´ )

where

Battery Low % (value stored in EE 0x54)=¸256.

A qualified discharge occurs if the battery discharges from RM ≥ FCC - Near Full*2 to the EDV2 voltage threshold with the following conditions:

No valid charge activity occurs during the discharge period. A valid charge is defined as an input of 10mAh into the battery.

No more than 256mAh of self-discharge and/or light discharge estimation occurs during the discharge period.

The temperature does not drop below 5°C during the discharge period.

The battery voltage reaches the EDV2 threshold during the discharge period and the voltage was less than the EDV2 threshold minus 256mV when the bq2060A detected EDV2.

No midrange voltage correction occurs during the discharge period.

There is no overload condition when voltage ≤ EDV2 threshold

+ ge to EDV2

(1)

bq2060A

FCC cannot be reduced by more than 256mAh or in creased by more than 512mAh during any single update cycle. The bq2060A saves the new FCC value to the EEPROM within 4s of being updated.

End-of-Discharge Thresholds and Capacity Cor rection

The bq2060A monitors the battery for three low-voltage thresholds, EDV0, EDV1, and EDV2. The EDV thresh olds are programmed in EDVF/EDV0 EE 0x72–0x73,

EMF/EDV1 EE 0x74–0x75, and EDV C1/C0 Fac tor/EDV2 EE 0x78–0x79. If the CEDV bit in Pack Con figuration is set, automatic EDV compensation is en

abled and the bq2060A computes the EDV0, EDV1, and EDV2 thresholds based on the values in EE 0x72–0x7d, 0x06, and the battery’s current discharge rate, tempera ture, capacity, and cycle count. The bq2060A disables EDV detection if Current() exceeds the Overload Current threshold programmed in EE 0x46 - EE 0x47. The bq2060A resumes EDV threshold detection after Cur rent() drops below the overload current threshold. Any EDV threshold detected will be reset after 10mAh of charge are applied.

The bq2060A uses the thresholds to apply voltage-based corrections to the RM register according to Table4.

Table 4. State of Charge Based

on Low Battery Voltage

Threshold State of Charge in RM

EDV0 0% EDV1 3% EDV2 Battery Low %

The bq2060A adjusts RM as it detects each threshold. If the voltage threshold is reached before the correspond ing capacity on discharge, the bq2060A reduces RM to the appropriate amount as shown in Table 4. If RM reaches the capacity level before the voltage threshold is reached on discharge, the bq2060A prevents RM from decreasing until the battery voltage reaches the corre sponding threshold, but only on a full learning-cycle dis charge (VDQ = 1). The EDV1 threshold is ignored if Mis cellaneous Options bit7=1.

Self-Discharge

The bq2060A estimates the self-discharge of the battery to maintain an accurate measure of the battery capacity during periods of inactivity. The algorithm for self-discharge estimation takes a programmed estimate for the expected self-discharge rate at 25°C stored in EEPROM and makes a fixed reduction to RM of an amount equal to RemainingCapacity()/256. The bq2060A makes the fixed reduction at a varying time interval that is adjusted to achieve the desired self-discharge

rate. This method maintains a constant granularity of

0.39% for each self-discharge adjustment, which may be performed multiple times per day, instead of once per day with a potentially large reduction.

The self-discharge estimation rate for 25°C is doubled

for each 10 degrees above 25°C or halved for each 10 de grees below 25°C. The following table shows the relation of the self-discharge estimation at a given temperature

to the rate programmed for 25°C (Y% per day):

Temperature ( C)

Temp < 10

10 ≤ Temp <20

20 ≤ Temp <30 30 ≤ Temp <40 40 ≤ Temp <50

50 ≤ Temp <60 60 ≤ Temp <70

70 ≤ Temp

Self-Discharge Rate

Y% per day

4 1

Y% per day

Y% per day 2Y% per day 4Y% per day 8Y% per day

16Y% per day 32Y% per day

The interval at which RM is reduced is given by the following equation, where n is the appropriate factor of 2

(n =

,1,2,...):

Self Disch e Update Time

arg

640 13500

n Y per day

··

256 ( % )

The timer that keeps track of the self-discharge update time is halted whenever charge activity is detected. The timer is reset to zero if the bq2060A reaches the RemainingCapacity()=FullChargeCapacity() condition while charging.

Example: IfT=35°C (n = 2) and programmed

self-discharge rate Y is 2.5 (2.5% per day at 25°C), the bq2060Areduces RM by RM/256 (0.39%) every

640 13500

256

··=n Y per day

(% )

6750

econds

This means that a 0.39% reduction of RM will be made

12.8 times per day to achieve the desired 5% per day re duction at 35°C.

Figure 3 illustrates how the self-discharge estimate al gorithm adjusts RemainingCapacity() vs. temperature.

Light Discharge or Suspend Current Compensation

The bq2060A can be configured in two ways to compen sate for small discharge currents that produce a signal

(2)

seconds

(3)

Figure 3. Self-Discharge at 2.5%/Day @25C

below the digital filter. First, the bq2060A can decrement RM and DCR at a rate determined by the value stored in Light Discharge Current EE 0x2b when it detects no dis charge activity and the SMBC and SMBD lines are high. Light Discharge Current has a range of 44µA to 11.2mA.

Alternatively, the bq2060A can be configured to disable the digital filter for discharge when the SMBC and SMBD lines are high. In this way, the digital filter will not mask the leakage current signal. The bq2060A is configured in this mode by setting the NDF bit in Con- trol Mode.

Midrange Capacity Corrections

The bq2060A applies midrange capacity corrections when the VCOR bit is set in Pack Configuration. The bq2060A adjusts RM to the associated percentage at three different voltage levels VOC25, VOC50, and VOC75. The VOC values represent the open circuit bat tery voltage at which RM corresponds to the associated state of charge for each threshold.

bq2060A

Threshold Associated State of Charge

VOC25 25% VOC50 50% VOC75 75%

For the midrange corrections to occur, the temperature must be in the range of 19°Cto31°C inclusive and the Current() and AverageCurrent() must both be between –64mA and 0. For a correction to occur, the bq2060A must also detect the need for correction during two adja cent measurements separated by 20s. The second mea surement is not required if the first measurement is im mediately after a device reset. The bq2060A makes midrange corrections as shown in Table5.

Charge Control

Charging Voltageand CurrentBroadcasts

The bq2060A supports SBS charge control by broadcasting the ChargingCurrent() and ChargingVoltage() to the Smart Charger address. The bq2060A broadcasts the requests every 10s. The bq2060A updates the values used in the charging current and voltage broadcasts based on the battery’s state of charge, voltage, and temperature. The fast-charge rate is programmed in Fast-Charging Current EE 0x1a - 0x1b while the charge voltage is programmed in Charging VoltageEE 0x0a-0x0b.

The bq2060A internal charge control is compatible with popular rechargeable chemistries. The primary charge-termination techniques include a change in temperature over a change in time (∆T/∆t) and current taper, for nickel-based and Li-Ion chemistries, respec tively. The bq2060A also provides pre-charge qualifica tion and a number of safety charge suspensions based on current, voltage, temperature, and state of charge.

Voltage()

Table 5. Midrange Corrections

Condition Result

≥ VOC75 and RelativeStateOfCharge() ≤ 63% RelativeStateOfCharge()→75% < VOC75 and RelativeStateOfCharge() ≥ 87% RelativeStateOfCharge()→75%

≥VOC50 and RelativeStateOfCharge() ≤ 38% RelativeStateOfCharge()→50%

<VOC50 and RelativeStateOfCharge() ≥ 62% RelativeStateOfCharge()→50% ≥ VOC25 and RelativeStateOfCharge() ≤ 13% RelativeStateOfCharge()→25% < VOC25 and RelativeStateOfCharge() ≥ 37% RelativeStateOfCharge()→25%

bq2060A

Alarm Broadcasts to SmartCharger andHost

If any of the bits 8–15 in BatteryStatus() is set, the bq2060A broadcasts an AlarmWarning() message to the Host address. If any of the bits 12–15 in BatteryStatus() is set, the bq2060A also sends an AlarmWarning() message to the Smart Charger address. The bq2060A repeats the AlarmWarning() message every 10s until the bits are cleared.

Pre-Charge Qualification

The bq2060A sets ChargingCurrent() to the pre-charge rate as programmed in Pre-Charge Current EE 0x1e-0x1f under the following conditions:

Voltage: The bq2060A requests the pre-charge

charge rate when Voltage() drops below the EDV0 threshold (compensated or fixed EDVs). Once requested, a pre-charge rate remains until Voltage() increases above the EDVF threshold. The bq2060A also broadcasts the pre-charge value immediately after a device reset until Voltage() is above the EDVF threshold. This threshold is programmed in EDVF/EDV0 EE 0x72-0x73.

Temperature: The bq2060A requests the

pre-charge rate when Temperature() is between 0°C and 5°C. Temperature() must rise above 5°C before the bq2060A requests the fast-charge rate.

Charge Suspension

The bq2060A may temporarily suspend charge if it detects a charging fault. A charging fault includes the following conditions.

Overcurrent: An overcurrent condition exists when the bq2060A measures the charge current to be more than the Overcurrent Margin above the ChargingCurrent(). Overcurrent Margin is programmed in EE 0x49. On detecting an overcurrent condition, the bq2060A sets the ChargingCurrent() to zero and sets the TERMINATE_CHARGE_ALARM bit in Battery Status(). The overcurrent condition and TERMINATE_ CHARGE_ALARM are cleared when the measured current drops below the ChargingCurrent plus the Overcurrent Margin.

Overvoltage: An overvoltage condition exists when the bq2060A measures the battery voltage to be more than the Overvoltage Margin above the ChargingVoltage() or a Li-Ion cell voltage has exceeded the overvoltage limit programmed in Cell Under-/Overoltage. Overvoltage

Margin is programmed in EE 0x48 and Cell Under/Over Voltage in EE 0x4a (least significant nibble). On

detecting an overvoltage condition, the bq2060A sets the ChargingCurrent() to zero and sets the TERMINATE_CHARGE_ALARM bit in BatteryStatus(). The bq2060A clears the TERMINATE_ CHARGE_ALARM bit when it detects that the battery

is no longer being charged (DISCHARGING bit set in BatteryStatus()). The bq2060A continues to broadcast zero charging current until the overvoltage condition is cleared. The overvoltage condition is cleared when the measured battery voltage drops below the ChargingVoltage() plus the Overvoltage Margin or when the CVOV bit is reset.

Over-Temperature: An over-temperature condition

exists when Temperature() is greater than or equal to the Max T value programmed in EE 0x45 (most significant nibble). On detecting an over-temperature condition, the bq2060A sets the ChargingCurrent() to zero and sets the OVER_TEMP_ALARM and TERMINATE_CHARGE_ ALARM bit in BatteryStatus() and the CVOV bit in Pack Status. The over-temperature condition is cleared when Temperature() is equal to or below (Max T –5°C). The temperature set by MaxT is increased by 16°Cif bit5inMiscellaneous Options is set.

Overcharge: An overcharge condition exists if the

battery is charged more than the Maxmum Overcharge value after RM = FCC. Maximum Overcharge is programmed in EE 0x2e–0x2f. On

detecting an overcharge condition, the bq2060A sets the ChargingCurrent() to zero and sets the OVER_CHARGED_ALARM, TERMINATE_CHARGE_ ALARM, and FULLY_CHARGED bits in BatteryStatus(). The bq2060A clears the OVER_ CHARGED_ALARM and TERMINATE_CHARGE_ ALARM when it detects that the battery is no longer being charged. The FULLY_CHARGED bit remains set and the bq2060A continues to broadcast zero charging current until RelativeStateOfCharge() is less than Fully Charged Clear% programmed in EE 0x4c.The counter used to track overcharge capacity is reset with 2mAh of discharge.

Under-Temperature: An under-temperature condition exists if Temperature() < 0°C. On detecting an under temperature condition, the bq2060A sets ChargingCurrent() to zero. The bq2060A sets ChargingCurrent() to the appropriate pre-charge rate or fast-charge rate when Temperature() ≥ 0°C.

Primary Charge Termination

The bq2060A terminates charge if it detects a charge-termination condition. A charge-termination condition includes the following.

∆T/∆t: For ∆T/∆t, the bq2060A detects a change in temperature over many seconds. The ∆T/∆t setting is programmable in both the temperature step,

DeltaT (1.6°C - 4.6°C), and the time step, DeltaT Time (20s-320s). Typical settings for 1°C/minute

include 2°C/120s and 3°C/180s. Longer times are required for increased slope resolution. The DeltaT value is programmed in EE 0x45 (least significant nibble) and the Delta T Time in EE 0x4e.

bq2060A

In addition to the ∆T/∆t timer, a hold-off timer starts when the battery is being charged at more than 255mA and the temperature is above 25°C. Until this timer expires, ∆T/∆t detection is suspended. If Current() drops below 256mA or Temperature() below 25°C, the hold-off timer resets and restarts only when the current and temperature conditions are met again. The hold-off timer is programmable (20s – 320s) with Holdoff Time value in EE 0x4f.

Current Taper: For current taper, ChargingVoltage()

must be set to the pack voltage desired during the constant-voltage phase of charging. The bq2060A detects a current taper termination when the pack voltage is greater than the voltage determined by Current Taper Qual Voltage in EE 0x4f and the charging current is below a threshold determined by Current Taper Threshold in EE 0x4e, for at least 80s. The bq2060A uses the VFC to measure current for current taper termination. The current must also remain above

0.5625/R

Once the bq2060A detects a primary charge termination, it sets the TERMINATE_CHARGE_ALARM and FULLY_CHARGED bits in BatteryStatus(), and sets the ChargingCurrent() to the maintenance charge rate as programmed in Maintenance Charging Current EE 0x1c–0x1d. On termination, the bq2060A also sets RM to a programmed percentage of FCC, provided that RelativeStateOfCharge() is below the desired percentage of FCC and the CSYNC bit in Pack Configu- ration EE 0x3f is set. If the CSYNC bit is not set and RelativeStateOfCharge() is less than the programmed percentage of FCC, the bq2060A clears the FULLY_CHARGED bit in BatteryStatus(). The programmed percentage of FCC, Fast Charge Termination %, is set in EE 0x4b. The bq2060A clears the FULLY_CHARGED bit when RelativeStateOfCharge() is less than the programmed Fully Charged Clear %. The bq2060A broadcasts the fast-charge rate when the FULLY_CHARGED bit is cleared and voltage and tem perature permit. The bq2060A clears the TERMI NATE_CHARGE_ALARM when it no longer detects that the battery is being charged or it no longer detects the termination condition. See Table 6 for a summary of BatteryStatus() alarm and status bit operation.

mA to qualify the termination condition.

Display Port

General

The display port drives a 4 or 5 LED bar-graph display. The display is activated by a logic signal on the DISP put. The bq2060A can display RM in either a relative or absolute mode with each LED representing a percentage of the full-battery reference. In relative mode, the bq2060A uses FCC as the full-battery reference; in abso lute mode, it uses DC.

The DMODE bit in Pack Configuration programs the bq2060A for the absolute or relative display mode. The

LED bit in Control Mode programs the 4 or 5 LED op tion. A 5th LED can be used with the 4 LED display op tion to show when the battery capacity is ≥to 100%.

Activation

The display may be activated at any time by a high-to-low transition on the DISP accomplished with a pullup resistor and a pushbutton switch. Detection of the transition activates the dis

and starts a four-second display timer. The timer

play expires and turns off the display whether

brought low momentarily or held low indefinitely. Reac tivation of the display requires that the DISP turn to a logic-high state and then transition low again. The second high-to-low transition must occur after the display timer expires. The bq2060A requires the DISP input to remain stable for a minimum of 250ms to detect the logic state.

If the EDV0 bit is set, the bq2060A disables the LED display. The display is also disabled during a VFC cali bration and should be turned off before entering low-power storage mode.

input. This is usually

DISP

Display Modes

In relative mode, each LED output represents 20% or 25% of the RelativeStateOfCharge() value. In absolute mode, each LED output represents 20% or 25% of the AbsoluteStateOfCharge() value. Tables 7A and 7B show the display operation.

In either mode, the bq2060A blinks the LED display if RemainingCapacity() is less than Remaining CapacityAlarm(). The display is disabled if EDV0= 1.

Secondary Protection for Li-Ion

The bq2060A has two pins, CFC and DFC, that can be

used for secondary override control of a Li-Ion protector

or for blowing a fuse to disable the battery pack. The

CFC pin is the Charge FET Control pin for secondary protector control or for blowing a fuse. The DFC pin is the Discharge FET Control pin for secondary protector control. Discharge current can cause an override of the CFC control, and charge current can cause an override of the DFC control. Pack Status can read the CVOV and CVUV status flags and can also read the true logic state of theCFC and DFC pins.

The CVOV status flag is set if Voltage() ≥ Charging Voltage() + Overvoltage Margin, any VCELL voltage ≥ Cell Overvoltage threshold, or if Temperature() ≥ MaxT. When CVOV=1 and Miscellaneous Options bit6=0,the CFC pin is pulled low unless DISCHARGING bit in

BatteryStatus() is set or Temperature() > Safety Overtemperature threshold. If Miscellaneous Options bit 6 = 1, the CPC pin is pulled low only if Temperature() >Safety Overtemperature threshold.

was

input re

bq2060A

Table 6. Alarm and Status Bit Summary

Battery State Conditions

Overcurrent

Overvoltage

Overtemperature

Overcharge

Undertemperature

Fast charge termination

Fully discharged

Overdischarged

Low capacity RM() < RCA() RCA = 1 Low run-time ATTE() < RTA() RTA= 1

C() ≥ CC() + Overcurrent

Margin

V() ≥ CV() + Overvoltage

Margin

VCELL1, 2, 3, or 4 > Cell

Over Voltage

T() ≥ Max T

Capacity added after

RM() = FCC() ≥

Maximum Overcharge

T()<0°C

∆T/∆t or Current Taper

V() ≤ EDV2

RM() < FCC()*Battery

Low%

V() ≤ EDV0

VCELL1, 2, 3 or 4 < Cell

Under Voltage

RM() = 0 TDA = 1

CC() State and

BatteryStatus Bits Set

CC() = 0, TCA = 1 C() < CC() + Overcurrent Margin

CC()=0,CVOV=1

CC()=0,OTA=1,

TCA = 1, CVOV = 1

CC() = 0, FC = 1 RSOC() < Fully Charged Cleared %

OCA = 1, TCA= 1 DISCHARGING = 1

CC() = Maintenance

Charging Current,

TDA = 1, CVUV = 1

CC() = Fast or Pre-charge Current

and/or Bits Cleared

TCA = 1 DISCHARGING = 1

V() < CV() + Overvoltage Margin

Li-Ion cell voltage ≤ Cell Over Voltage

T() ≤ Max T -5°CorT()≤ 43°C

CC() = 0

FC=1

TCA = 1

FD = 1 RSOC() > 20%

TDA = 1 V() > EDV0

0°C ≤ Τ() < 5°C, CC() = Pre-Charge

Current

T() ≥5°C, CC() = Fast-Charging Current

RSOC() < Fully Charged Cleared %

DISCHARGING=1ortermination

condition is no longer valid.

VCELL1, 2, 3, or 4 ≥ Cell Under Voltage

RM() > 0

RM() ≥ RCA()

ATTE() ≥ RTA()

Note: C() = Current(), CV() = ChargingVoltage(), CC() = ChargingCurrent(), V() = Voltage(), T() = Tempera

ture(), TCA = TERMINATE_CHARGE_ALARM,OTA = OVER_TEMPERATURE_ALARM, OCA = OVER_CHARGED_ALARM, TDA= TERMINATE_DISCHARGE_ALARM, FC = FULLY_CHARGED, FD = FULLY_DISCHARGED, RSOC() = RelativeStateOfCharge(). RM() = RemainingCapacity(), RCA = REMAINING_CAPACITY_ALARM, RTA= REMAINING_TIME_ALARM, ATTE() = AverageTimeToEmpty(), RTA() = RemainingTimeAlarm(), RCA() = RemainingCapacityAlarm(), FCC() = FullChargeCapacity.

bq2060A

Table 7A. Display Mode

Condition

Relative or

Absolute

StateOfCharge()

EDV0 = 1 OFF OFF OFF OFF OFF

<20% ≥20%, <40% ≥40%, <60% ≥60%, <80%

≥80%

The CVUV status flag is set if any VCELL voltage < Cell Undervoltage threshold. When CVUV = 1, the DVC pin

is pulled low unless DISCHARGING bit in BatteryStatus() is set or Temperature() is not set.

Cell Undervoltage and Cell Overvoltage limits may be programmed in the upper and lower nibbles of EE 0x4a. Safety Overtemperature threshold may be programmed in EE 0x09, and Miscellaneous Options is programmed in EE 0x08.

5 LED Display Option

LED1 LED2 LED3 LED4 LED5

ON OFF OFF OFF OFF ON ON OFF OFF OFF ON ON ON OFF OFF ON ON ON ON OFF ON ON ON ON ON

Low-Power Storage Mode

The bq2060A enters low-power mode 5– 8s after receiving the Enable Low-Power command. In this mode the bq2060A consumes less than 10µA. A rising edge on SMBC, SMBD, or HDQ16 restores the bq2060A to the full operating mode. The bq2060A does not perform any gas gauge functions during low-power storage mode.

Device Reset

The bq2060A can be reset when power is applied or by commands over the HDQ16 or SMBus. Upon reset, the bq2060A initializes its internal registers with the infor mation contained in the configuration EEPROM. The following command sequence initiates a full bq2060A re set:

Write 0xff5a to address 0x4f Write 0x0000 to address 0x7d Write 0x0080 to address 0x7d

A partial reset of the bq2060A occurs if step 1 is omitted and all check-byte values previously loaded into RAM are still correct. All initial RAM values are read from EEPROM for both full and partial resets. A full reset initializes MaxError = 100%, sets RELEARN_FLAG (bit

7)=1inBattery Mode, and initializes RM from EE 0x2c–2d (should be zero for rechargeable batteries). A

Table 7B. Display Mode

Condition

Relative or

Absolute

StateOfCharge()

EDV0 = 1 OFF OFF OFF OFF

<25% ≥25%, <50% ≥50%, <75%

≥75%

partial reset leaves MaxError, RELEARN_FLAG, and RM unchanged. The bq2060A delays reading the EEPROM for 700ms after all resets to allow settling time for V

4 LED Display Option

LED1 LED2 LED3 LED4

ON OFF OFF OFF ON ON OFF OFF ON ON ON OFF ON ON ON ON

Communication

The bq2060A includes two types of communication ports: SMBus and HDQ16. The SMBus interface is a 2-wire bidirectional protocol using the SMBC (clock) and SMBD (data) pins. The HDQ16 interface is a 1-wire bidirectional protocol using the HDQ16 pin. All three communication lines are isolated from V pulled-up higher than V pull these lines low if V should be pulled down with a 100KΩ resistor if not used.

The communication ports allow a host controller, an SMBus compatible device, or other processor to access the memory registers of the bq2060A. In this way a sys tem can efficiently monitor and manage the battery.

SMBus

The SMBus interface is a command-based protocol. A

processor acting as the bus master initiates communica tion to the bq2060A by generating a START condition. A START condition consists of a high-to-low transition of the SMBD line while the SMBC is high. The processor then sends the bq2060A device address of 0001011 (bits 7–1) plus a R/W mand code. The R/W the bq2060A to either store the forthcoming data to a register specified by the SMBus command code or out put the data from the specified register. The processor completes the access with a STOP condition. A STOP condition consists of a low-to-high transition of the SMBD line while the SMBC is high. With SMBus, the most significant bit ofa data byte is transmitted first.

bit (bit 0) followed by an SMBus com

. Also, the bq2060A will not

to the part is zero . HDQ16

bit and the command code instruct

and may be

bq2060A

In some instances, the bq2060A acts as the bus master. This occurs when the bq2060A broadcasts charging re quirements and alarm conditions to device addresses 0x12 (SBS Smart Charger) and 0x10 (SBS Host Control ler.)

SMBus Protocol

The bq2060Asupports the following SMBus protocols:

Read Word

Write Word

Read Block

A processor acting as the bus master uses the three pro tocols to communicate with the bq2060A. The bq2060A acting as the bus master uses the WriteWordprotocol.

The SMBD and SMBC pins are open drain and require external pullup resistors.

SMBus Packet Error Checking

The bq2060A supports Packet Error Checking as a mechanism to confirm proper communication between it and another SMBus device. Packet Error Checking requires that both the transmitter and receiver calculate a Packet Error Code (PEC) for each communication message. The device that supplies the last byte in the communication message appends the PEC to the message. The receiver compares the transmitted PEC to its PEC result to determine if there is a communication error.

PEC Protocol

The bq2060A can receive or transmit data with or with out PEC. Figure 4 shows the communication protocol for the Read Word, Write Word, and Read Block mes sages without PEC. Figure 5 includes PEC.

In the Write Word protocol, the bq2060A receives the PEC after the last byte of data from the host. If the host does not support PEC, the last byte of data is followed by a STOP condition. After receipt of the PEC, the bq2060A compares the value to its calculation. If the PEC is correct, the bq2060A responds with an AC KNOWLEDGE. If it is not correct, the bq2060A re sponds with a NOT ACKNOWLEDGE and sets an error code.

In the Read Word and Block Read, the host generates an ACKNOWLEDGE after the last byte of data sent by the bq2060A. The bq2060A then sends the PEC and the host acting as a master-receiver generates a NOT AC KNOWLEDGE and a STOPcondition.

PEC Calculation

The basis of the PEC calculation is an 8-bit Cyclic Re dundancy Check (CRC-8) based on the polynomial C(X)

8+X2+X1

bytes in the transmission, including address, command, and data. The PEC calculation does not include AC

KNOWLEDGE, NOT ACKNOWLEDGE, START, STOP,

+ 1. The PEC calculation includes all

and Repeated START bits. For example, the host requests RemainingCapacity()

from the bq2060A. This includes the host following the Read Word protocol. The bq2060A calculates the PEC based on the following 5 bytes of data, assuming the re maining capacity of the battery is 1001mAh.

Battery Address with R/W = 0: 0x16

Command Code for RemainingCapacity(): 0x0f

Battery Address with R/W = 1: 0x17

RemainingCapacity(): 0x03e9

For 0x160f17e903, the bq2060A transmits a PEC of 0xe8 to the host.

PEC Enable in Master Mode

PEC for master mode broadcasts to the charger, host, or both can be enabled/disabled with the combination of the bits HPE and CPE in Control Mode.

SMBus On and Off State

The bq2060A detects whether the SMBus enters the Off State” by monitoring the SMBC and SMBD lines. When both signals are continually low for at least 2.5s, the bq2060A detects the Off State. When the SMBC and SMBD lines go high, the bq2060A detects the On State and can begin communication within 1ms. One-MΩ pulldown resistors on SMBC and SMBD are recom mended for reliable Off State detection.

HDQ16

The HDQ16 interface is a command-based protocol. (See

Figure 6.) A processor sends the command code to the bq2060A. The 8-bit command code consists of two fields, the 7-bit HDQ16 command code (bits 0–6) and the 1-bit R

/W field. The R/W field directs the bq2060Aeither to

Store the next 16 bits of data to a specified register or

Output 16 bits of data from the specified register

With HDQ16, the least significant bit of a data byte

(command) or word (data) is transmitted first. A bit transmission consists of three distinct sections. The

first section starts the transmission by either the host or the bq2060A taking the HDQ16 pin to a logic-low state

for a period t data-transmission, where the data bit is valid by the time, t nication. The data bit is held for a period t the host processor or bq2060Ato sample the data bit.

after the negative edge used to start commu

DSU;B

. The next section is the actual

STRH;B

DH;DV

to allow

Figure 4. SMBus Communication Protocol without PEC

bq2060A

Figure 5. SMBus Communication Protocol with PEC

bq2060A

The final section is used to stop the transmission by re turning the HDQ16 pin to a logic-high state by at least the time t communication. The final logic-high state should be un til a period t transmission was stopped properly.

If a communication error occurs (e.g., t host sends the bq2060A a BREAK to reinitiate the serial

after the negative edge used to start

SSU;B

to allow time to ensure that the bit

CYCH;B

CYCB

> 250µs), the

interface. The bq2060A detects a BREAK when the HDQ16 pin is in a logic-low state for a time t greater. The HDQ16 pin is then returned to its normal ready-high logic state for a time t then ready to receive a command from the host proces

. The bq2060A is

sor. The HDQ16 pin is open drain and requires an external

pullup resistor.

Command Codes

The SMBus Command Codes are in ( ), the HDQ16 in [ ]. T emperature(), Voltage(), Current(), and AverageCurrent(), performance specifications are at regulated V and a temperature of 0–70°C.

ManufacturerAccess() (0x00); [0x00–0x01]

Description:

This function provides writable command codes to control the bq2060A during normal operation and pack manufacture. These commands can be ignored if sent within one second after a device reset. The following list of commands are available.

0x0618 Enable Low-Power Storage Mode: Activates the low-power storage mode. The bq2060A enters the storage mode after a 5–8s delay. The bq2060A accepts other commands to ManufacturerAccess() during the delay before entering low-power storage mode. The

CC(VRO

LEDs must be off before entering the low-power storage

mode as the display state remains unchanged.

The bq2060Aclears the ManufacturerAccess() command within 900ms of acknowledging the Enable Low-Power Storage command. The VFC Calibration command may be sent 900–5000ms after SMBus acknowledgment of the Enable Low-Power Storage command. In this case, the bq2060A delays entering storage mode until the cali bration process completes and the bq2060A stores the new calibration values in EEPROM.

0x062b SEAL: Instructs the bq2060A to restrict access

to those functions listed in Table 3. The bq2060A com pletes the seal function and clears ManufacturerAccess() within 900ms of acknowledging the command.

0x064d Charge Synchronization: Instructs the bq2060A to update RM to a percentage of FCC as defined in Fast Charge Termination %. The bq2060A updates RM and clears ManufacturerAccess() within 900ms of acknowledging the command.

)

0x0653 Enable VFC Calibration: Instructs the unsealed bq2060A to begin VFC calibration. With this command the bq2060A deselects the SR

and SR2 inputs

and calibrates for IC offset only. It is best to avoid charge or discharge currents through the sense resistor during this calibration process.

0x067e Alternate VFC Calibration: Instructs the unsealed bq2060A to begin VFC calibration. With this command, the bq2060A does not deselect the SR SR

inputs and does calibrate for IC and PCB offset.

During this procedure no charge or discharge currents

During VFC calibration, the bq2060A disables the LED display and accepts only the Stop VFC Calibration and

and

Figure 6. HDQ16 Communication Example

bq2060A

the SEAL commands to ManufacturerAccess(). The bq2060A disregards all other commands. SMBus communication should be kept to a minimum during VFC calibration to reduce the noise level and allow a more accurate calibration.

Once started, the VFC calibration procedure completes automatically. When complete, the bq2060A saves the calibration values in EEPROM. The calibration nor mally takes about 8 to 10 minutes. The calibration time is inversely proportional to the bq2060A VFC (and PCB) offset error. The bq2060A caps the calibration time at one hour in the event of calibrating zero offset error. The VFC calibration can be done as the last step in a battery pack test procedure since the calibration can complete automatically after removal from a test setup.

The bq2060A clears ManufacturerAccess() within 900ms and starts calibration within 3.2s of acknowledging the command.

0x0660 Stop VFC Calibration: Instructs the bq2060A to abort a VFC calibration procedure. If aborted, the bq2060A disables offset correction. The bq2060A stops calibration within 20ms of acknowledging the command.

0x0606 Program EEPROM: Instructs the unsealed bq2060A to connect the SMBus to the EEPROM I

C bus. The bq2060A applies power to the EEPROM within 900ms of acknowledging the command. After issuing the program EEPROM command, the bq2060A monitoring functions are disabled until the I The bq2060A disconnects the I the Battery Address 0x16 is sent over the SMBus. The Battery Address 0x16 to disconnect the I

C bus is disconnected.

C bus when it detects that

C bus should not be sent until 10ms after the last write to the EEPROM.

Example: The following sequence of actions is an exam ple of how to use the ManufacturerAccess() commands in an efficient manner to take a battery pack that has completed all testing and calibration except for VFC cal ibration and to make it ready for shipment in the SEALED state and in low-power storage mode:

1. Complete testing and calibration with desired final

values stored in EEPROM. This process includes setting the SEAL bit in Pack Configuration. Sending a reset command to the bq2060A during test ensures that RAM values correspond to the fi nal EEPROM values

2. If the initial value of RemainingCapacity() must be

non-zero, the desired value may be written to Com mand 0x26 with the pack unsealed. A reset sent af ter this step resetsRM to zero.

3. Issue the Enable Low-Power Storage Mode com

mand.

4. Within 900–1600ms after sending the Enable

Low-Power command, issue the Enable VFC Cali

bration command. This delays the low-power storage mode until after VFC calibration comple tion.

5. Issue the SEAL Command subsequent to the VFC Calibration command. The bq2060A must receive the SEAL Command before VFC calibration com pletes. The bq2060A resets the OCE bit in Pack

Status when calibration begins and sets the bit when calibration successfully completes.

After VFC calibration completes automatically, the bq2060A saves the VFC offset cancellation values in EEPROM and enters the low-power storage mode in about 20s. In addition, the bq2060A is sealed, allowing access as defined in Table3 only.

Purpose:

The ManufacturerAccess() function provides the system host access to bq2060A functions that are not defined by the SBD.

SMBus Protocol: Reador WriteWord Input/Output: Word

RemainingCapacityAlarm() (0x01); [0x01]

Description:

Sets or gets the low-capacity threshold value. Whenever the RemainingCapacity() falls below the low capacity value, the bq2060A sends AlarmWarning() messages to the SMBus Host with the REMAINING_CAPACITY_ALARM bit set. A low-capacity value of 0 disables this alarm. The bq2060A initially sets the low-capacity value to Remaining Capacity Alarm value programmed in EE 0x04 - 0x05. The low-capacity value remains unchanged until altered by the RemainingCapacityAlarm() function. The low-capacity value may be expressed in either current (mA) or power (10mWh)

depending on the setting of the BatteryMode()’s CAPAC ITY_MODE bit.

Purpose:

The RemainingCapacityAlarm() function can be used by systems that know how much power they require to save their operating state. It enables those systems to more finely control the point at which they transition into suspend or hibernate state. The low-capacity value can be read to verify the value in use by the bq2060’s

low capacity alarm. SMBus Protocol: Read or WriteWord

Input/Output: Unsigned integer—value below which

Low Capacity messages are sent.

bq2060A

Battery Modes

CAPACITY_MODE

bit=0

Units mAh @ C/5 10mWh @ P/5

Range 0–65,535mAh 0–65,535 10mWh

Granularity Not applicable

Accuracy See RemainingCapacity()

RemainingTimeAlarm() (0x02); [0x02]

Description:

Sets or gets the remaining time alarm value. Whenever the AverageTimeToEmpty() falls below the remaining time value, the bq2060A sends AlarmWarning() messages to the SMBus Host with the REMAINING_TIME_ALARM bit set. A remaining time value of 0 effectively disables this alarm. The bq2060A initially sets the remaining time value to the Remaining Time Alarm value programmed in EE 0x02 0x03. The remaining time value remains unchanged until altered by the RemainingTimeAlarm()function.

Purpose:

The RemainingTimeAlarm() function can be used by systems that want to adjust when the remaining time alarm warning is sent. The remaining time value can be read to verify the value in use by the bq2060’s RemainingTimeAlarm().

SMBus Protocol: Read or WriteWord Input/Output:

Unsigned integer—the point below which remain ing time messages are sent.

Units: minutes Range: 0to 65,535 minutes Granularity: Notapplicable

Accuracy: seeAverageTimeToEmpty()

BatteryMode() (0x03); [0x03]

Description:

This function selects the various battery operational modes and reports the battery’smode and requests.

Defined modes include

Whether the battery’s capacity information is specified in mAh or 10mWh (CAPACITY_MODE bit)

Whether the ChargingCurrent() and ChargingVoltage() values are broadcast to the Smart Battery Charger when the bq2060A detects the battery requires charging (CHARGER_MODE bit)

CAPACITY_MODE

bit=1

Whether all broadcasts to the Smart Battery Charger

and Host are disabled

The defined request condition is the battery requesting a conditioning cycle (RELEARN_FLAG).

Purpose:

The CAPACITY_MODE bit allows power management systems to best match their electrical characteristics with those reported by the battery. For example, a switching power supply represents a constant power load, whereas a linear supply is better represented by a constant current model. The CHARGER_MODE bit al lows a SMBus Host or Smart Battery Charger to over ride the Smart Battery’s desired charging parameters by disabling the bq2060’s broadcasts. The RE LEARN_FLAG bit allows the bq2060A to request a con ditioning cycle.

SMBus Protocol: Read or WriteWord Input/Output:

Unsigned integer —bit mapped— see below. Units: notapplicable Range: 0–1 Granularity: notapplicable Accuracy: notapplicable

The BatteryMode() word is divided into two halves, the most significant bit (bits 8–15), which is read/write and the least significant bit (bits 0–7), which is read only. The bq2060A forces bits 0–6 to zero and prohibits writes

to bit 7. Table 8 summarizes the meanings of the individual bits

in the BatteryMode() word and specifies the default val ues, where applicable, are noted.

INTERNAL_CHARGE_CONTROLLER bit is not used by the bq2060A.

PRIMARY_BATTERY_SUPPORT bit is not used by the bq2060A.

RELEARN_FLAG bit set indicates that the bq2060A is requesting a capacity relearn cycle for the battery. The bq2060A sets the RELEARN_FLAG under any of three conditions: full reset, detection of 20 cycle counts with out an FCC update, or a midrange voltage correction. The bq2060A clears this flag after a learning cycle has been completed.

CHARGE_CONTROLLER_ENABLED bit is not used by the bq2060A. The bq2060Aforces this bit to zero.

PRIMARY_BATTERY bit is not used by the bq2060A. The bq2060Aforces this bit to zero.

Table 8. Battery Mode Bits and Values

Battery Mode() Bits Bits Used Format Allowable Values

INTERNAL_CHARGE_CONTROLLER 0 Read only bit flag

PRIMARY_BATTERY_SUPPORT 1 Read only bit flag

Reserved 2–6

RELEARN_FLAG 7 Read only bit flag

CHARGE_CONTROLLER_ENABLED 8 R/W bit flag

PRIMARY_BATTERY 9 R/W bit flag

Reserved 10–12

ALARM_MODE 13 R/W bit flag

CHARGER_MODE 14 R/W bit flag

CAPACITY_MODE 15 R/W bit flag

bq2060A

0—Battery OK 1—Relearn cycle requested

0—Enable alarm broadcast (default) 1—Disable alarm broadcast

0—Enable charging broadcast

(default)

1—Disable charging broadcast 0—Report in mAor mAh (default)

1—Report in 10mW or 10mWh

ALARM_MODE bit is set to disable the bq2060’s ability to master the SMBus and send AlarmWarning() messages to the SMBus Host and the Smart Battery Charger. When set, the bq2060A does NOT master the SMBus, and AlarmWarning() messages are NOT sent to the SMBus Host and the Smart Battery Charger for a period of no more than 65s and no less than 45s. When cleared (default), the Smart Battery sends the AlarmWarning() messages to the SMBus Host and the Smart Battery Charger any time an alarm condition is detected.

The bq2060A polls the ALARM_MODE bit at least every 150ms. Whenever the ALARM_MODE bit is set, the bq2060A resets the bit and starts or restarts a 55s (nominal) timer. After the timer expires, the bq2060A automatically enables alarm broadcasts to ensure that the accidental deactivation of broadcasts does not persist. To prevent the bq2060A from becoming a master on the SMBus, an SMBus host must therefore continually set this bit at least once per 50s to keep the bq2060A from broadcasting alarms.

The ALARM_MODE bit defaults to a cleared state within 130ms after the bq2060A detects the SMBus Off-State.

The condition of the ALARM-MODE bit does NOT affect the operation or state of the CHARGER_MODE bit which is used to prevent broadcasts of ChargingCurrent() and ChargingVoltage() to the Smart Battery Charger.

CHARGER_MODE bit enables or disables the bq2060’s transmission of ChargingCurrent() and ChargingVoltage() messages to the Smart Battery

Charger. When set, the bq2060A does NOT transmit ChargingCurrent() and ChargingVoltage() values to the Smart Battery Charger. When cleared, the bq2060A transmits the ChargingCurrent() and ChargingVoltage() values to the Smart Battery Charger. The CHARGER_MODE bit defaults to a cleared state within 130ms after the bq2060A detects the SMBus Off-State.

CAPACITY_MODE bit indicates if capacity information is reported in mA/mAh or 10mW/10mWh. When set, the bq2060A reports capacity information in 10mW/10mWh as appropriate. When cleared, the bq2060A reports capacity information in mA/mAh as ap propriate. The CAPACITY_MODE bit defaults to a cleared state within 130ms after the bq2060A detects the SMBus Off-State.

Note 1: The following functions are changed to accept or return values in mA/mAh or 10mW/10mWh depending on the CAPACITY_MODEbit:

RemainingCapacityAlarm()

AtRate()

RemainingCapacity()

FullChargeCapacity()

DesignCapacity()

Note 2: The following functions are calculated on the basis of capacity and may be calculated differently de pending on the CAPACITY_MODEbit:

bq2060A

AtRateOK()

AtRateTimeToEmpty()

AtRateTimeToFull()

RunTimeToEmpty()

AverageTimeToEmpty()

AverageTimeToFull()

Remaining Time Alarm()

BatteryStatus()

The bq2060A updates the non-AtRate related register values within 3s of changing the state of the CAPAC ITY_MODE bit. The AtRate() values will be updated af ter the next AtRate value is written to the bq2060A (or after the next 20s scheduled refresh calculation).

AtRate() (0x04); [0x04]

Description:

The AtRate() function is the first half of a two-function call-set used to set the AtRate value used in calculations made by the AtRateTimeToFull(), AtRateTimeToEmpty(), and AtRateOK() functions. The AtRate value may be expressed in either current (mA) or power (10mW) depending on the setting of the BatteryMode()’s CAPACITY_MODEbit.

Purpose:

Since the AtRate() function is the first half of a two-function call-set, it is followed by the second function of the call-set that calculates and returns a value based on the AtRate value and the battery’s present state. A delay of up to 1.3s is required after writing AtRate() before the bq2060A can acknowledge the re quested AtRate function.

When the AtRate() value is positive, the AtRateTimeToFull() function returns the predicted time to full-charge at the AtRate value of charge.

When the AtRate() value is negative, the AtRateTimeToEmpty() function returns the predicted operating time at the AtRate value of discharge.

When the AtRate() value is negative, the AtRateOK() function returns a Boolean value that predicts the battery’s ability to supply the AtRate value of additional discharge energy (current or power) for 10 seconds.

The default value for AtRate() is zero. Writing AtRate() values over the HDQ16 serial port does NOT trigger a re-calculation of AtRateTimeToFull(), AtRateTimeToEmpty(),and AtRateOK() functions.

It is recommended that AtRate() requests should be lim ited to one request every 4s.

SMBus Protocol: Read or WriteWord Input/Output: Signed integer—charge or discharge;

the AtRate() value is positive for charge, negative for discharge, and zero for neither (default).

Battery Mode

CAPACITY_MODE

bit=0

CAPACITY_MODE

bit=1

Units mA 10mW

Charge

Range

Discharge

Range

Granularity 1 Unit

1–32,767mA 1–32,768 10mW

-1– -32,768mA -1–-32,768 10mW

Accuracy NA

AtRateTimeToFull() (0x05);[0x05]

Description:

Returns the predicted remaining time to fully charge the battery at the AtRate( ) value (mA).

Purpose:

The AtRateTimeToFull() function is part of a two-function call-set used to determine the predicted remaining charge time at the AtRate value in mA. The bq2060A updates AtRateTimeToFull() within 1.3s after the SMBus Host sets the AtRate value. If read before this delay, the command is No Acknowledged and the error code in BatteryStatus is set to not ready. The bq2060A automatically updates AtRateTimeToFull() based on the AtRate() value every 20s.

SMBus Protocol: Read Word Output:

Unsigned integer—predicted time in minutes to fully charge the battery.

Units: minutes Range: 0 to 65,534 min Granularity: 2 min or better Accuracy: ±MaxError()

FullChargeCapacity()/|AtRate()| Invalid Data Indication: 65,535 indicates the bat

tery is not being charged.

bq2060A

AtRateTimeToEmpty() (0x06); [0x06]

Description:

Returns the predicted remaining operating time if the battery is discharged at the AtRate() value.

Purpose:

The AtRateTimeToEmpty() function is part of a two-function call-set used to determine the remaining operating time at the AtRate()value. The bq2060A up dates AtRateTimeToEmpty() within 1.3s after the SMBus Host sets the AtRate() value. If read before this delay, the command is No Acknowledged, and the error code in BatteryStatus is set to not ready. The bq2060A automatically updates AtRateTimeToEmpty() based on the AtRate() value every 20s.

SMBus Protocol: Read Word Output:

Unsigned integer — estimated operating time left. Units: minutes Range: 0to 65,534 min Granularity: 2min or better Accuracy: -0, +MaxError()

FullChargeCapacity/|AtRate()| Invalid Data Indication: 65,535 indicates the bat-

tery is not being discharged.

AtRateOK() (0x07); [0x07]

Description:

Returns a Boolean value that indicates whether or not the battery can deliver the AtRate( )value of additional energy for 10 seconds (Boolean). If the AtRate value is zero or positive, the AtRateOK() function ALWAYS re turn-true.

Purpose:

The AtRateOK() function is part of a two-function call-set used by power management systems to deter mine if the battery can safely supply enough energy for an additional load. The bq2060A updates AtRateOK() within 1.3s after the SMBus Host sets the AtRate( ) value. If read before this delay, the command is No Ac knowledged, and the error code in BatteryStatus is set to not ready. The bq2060A automatically updates AtRateOK() based on the At Rate() value every 20s.

SMBus Protocol: Read Word Output:

Boolean—indicates if the battery can supply the additional energy requested.

Units: Boolean

Range: TRUE,FALSE Granularity: notapplicable Accuracy: notapplicable

Temperature() (0x08); [0x08]

Description:

Returns the temperature (K) measured by the bq2060A.

Purpose:

The Temperature() function provides accurate cell tem peratures for use by battery chargers and thermal man agement systems. A battery charger can use the tem perature as a safety check. Thermal management sys tems may use the temperature because the battery is one of the largest thermal sources in a system.

SMBus Protocol: Read Word Output:

Unsigned integer—cell temperature in tenth-degree Kelvin increments.

Units: 0.1°K Range: 0to +6553.5°K {realrange} Granularity: 0.1°K Accuracy: ±1.5°K (from ideal 103AT thermistor

performance, after calibration)

Voltage()(0x09); [0x09]

Description:

Returns the cell-pack voltage (mV).

Purpose:

The Voltage() function provides power management sys

tems with an accurate battery terminal voltage. Power management systems can use this voltage, along with battery current information, to characterize devices they control. This ability helps enable intelligent, adaptive power-managementsystems.

SMBus Protocol: Read Word Output:

Unsigned integer—battery terminal voltage in mV.

Units: mV Range: 0to 20,000 mV

Granularity: 1mV Accuracy: ±0.65% (after calibration)

bq2060A

Current() (0x0a); [0x0a]

Description:

Returns the current being supplied (or accepted) through the battery’sterminals (mA).

Purpose:

The Current() function provides a snapshot for the power management system of the current flowing into or out of the battery. This information is of particular use in power-management systems because they can charac terize individual devices and tune their operation to ac tual system power behavior.

SMBus Protocol: Read Word Output:

Signed integer—charge/discharge rate in mA incre ments—positive for charge, negative for discharge.

Units: mA Range: (±250mV/R Granularity: 0.038mV/R Accuracy: ±1mV/R

)mA

(integer value)

(after calibration)

AverageCurrent()(0x0b); [0x0b]

Description:

Returns a value that approximates a one-minute rolling average of the current being supplied (or accepted) through the battery’s terminals (mA). The AverageCurrent() function will return meaningful values during the battery’sfirst minute of operation.

Purpose:

The AverageCurrent() function provides the average cur rent flowing into or out of the battery for the power management system.

SMBus Protocol: Read Word Output:

Signed integer—charge/discharge rate in mA incre ments—positive for charge, negative for discharge.

Units: mA Range: (±250mV/R Granularity: 0.038mV/R Accuracy: ±1mV/R

)mA

(integer value)

(after calibration)

MaxError() (0x0c); [0x0c]

Description:

Returns the expected margin of error (%) in the state of charge calculation. For example, when MaxError() re turns 10% and RelativeStateOfCharge() returns 50%,

the Relative StateOfCharge() is more likely between 50 and 60%. The bq2060A sets MaxError() to 100% on a full reset. The bq2060A sets MaxError() to 2% on com pletion of a learning cycle, unless the bq2060A limits the learning cycle to the +512/-256mAh maximum ad justment values. If the learning cycle is limited, the bq2060A sets MaxError() to 8% unless MaxError() was already below 8%. In this case MaxError() does not change. The bq2060A increments MaxError() by 1% af

ter four increments of CycleCount() without a learning

cycle. If voltage-based corrections are applied to the coulomb

counter,MaxError() is set to 25%.

Purpose:

The MaxError() function has real value in two ways:

first, to give the user a confidence level about the state

of charge and second, to give the power management system information about how aggressive it should be, particularly as the battery nears the end of its life.

SMBus Protocol: Read Word Output:

Unsigned integer—percent uncertainty for selected information.

Units: % Range: 2to 100% Granularity: 1% Accuracy: notapplicable

RelativeStateOfCharge() (0x0d); [0x0d]

Description:

Returns the predicted remaining battery capacity ex pressed as a percentage of FullChargeCapacity() (%).

Purpose:

The RelativeStateOfCharge() function is used to esti mate the amount of charge remaining in the battery rel

ative to the last learned capacity.

SMBus Protocol: Read Word Output:

Unsigned integer—percent of remaining capacity. Units: % Range: 0to 100% Granularity: 1%

Accuracy: -0,+MaxError()

bq2060A

AbsoluteStateOfCharge()(0x0e); [0x0e]

Description:

Returns the predicted remaining battery capacity ex pressed as a percentage of DesignCapacity() (%). Note that AbsoluteStateOfCharge() can return values greater than 100%.

Purpose:

The AbsoluteStateOfCharge() function is used to esti mate the amount of charge remaining in the battery rel ative to the nominal or DesignCapacity().

SMBus Protocol: Read Word Output:

Unsigned integer—percent of remaining capacity. Units: % Range: 0to 100+% Granularity: 1% Accuracy: -0,+MaxError()

RemainingCapacity() (0x0f); [0x0f]

Description:

Returns the predicted charge or energy remaining in the battery. The RemainingCapacity() value is expressed in either charge (mAh at a C/5 discharge rate) or energy (10mWh at a P/5 discharge rate) depending on the setting of the BatteryMode()’sCAPACITY_MODEbit.

Purpose:

The RemainingCapacity() function returns the battery’s remaining capacity. This information is a numeric indica tion of remaining charge or energy given by the Absolute or Relative StateOfCharge() functions and may be in a better form for use by power management systems.

SMBus Protocol: Read Word Output:

Unsigned integer—remaining charge in mAh or 10mWh.

Battery Mode

CAPACITY_MODE

bit=0

Units mAh 10mWh

Range 0–65,535mAh 0–65,535 10mWh

Granularity mAh 10mWh

Accuracy

-0, +MaxError() ∗ FullChargeCapacity()

CAPACITY_MODE

bit=1

FullChargeCapacity() (0x10); [0x10]

Description:

Returns the predicted pack capacity when it is fully

charged. The FullChargeCapacity() value is expressed in either current (mAh at a C/5 discharge rate) or power (10mWh at a P/5 discharge rate) depending on the set ting of the BatteryMode()’sCAPACITY_MODEbit.

Purpose:

The FullChargeCapacity() function provides the user

with a means of understanding the tank size of their battery. This information, along with information about the original capacity of the battery, can be presented to the user as an indication of battery wear.

SMBus Protocol: Read Word Output:

Unsigned integer—estimated full-charge capacity in mAh or 10mWh.

Battery Mode

CAPACITY_MODE

bit=0

Units mAh 10mWh

Range 0–65,535mAh 0–65,535 10mWh

Granularity mAh 10mWh

Accuracy

-0, +MaxError() ∗ FullChargeCapacity()

CAPACITY_MODE

bit=1

RunTimeToEmpty() (0x11);[0x11]

Description:

Returns the predicted remaining battery life at the pres

ent rate of discharge (minutes). The RunTimeToEmpty() value is calculated based on either current or power depending on the setting of the BatteryMode()’sCAPACITY_MODEbit.

Purpose:

The RunTimeT oEmpty() provides the power management system with information about the relative gain or loss in remaining battery life in response to a change in power policy. This information is NOT the same as the AverageTimeToEmpty(), which is not suitable to deter mine the effects that result from a change in power policy.

SMBus Protocol: Read Word Output:

Unsigned integer—minutes of operation left. Units: minutes Range: 0to 65,534 min Granularity: 2min or better

bq2060A

Accuracy: -0, +MaxError() ∗ FullChargeCapacity() / Current()

Invalid Data Indication: 65,535 indicates battery is not being discharged.

AverageTimeToEmpty() (0x12);[0x12]

Description: Returns a one-minute rolling average of the predicted remaining battery life (minutes). The AverageTimeToEmpty() value is calculated based on ei ther current or power depending on the setting of the BatteryMode()’sCAPACITY_MODEbit.

Purpose:

The AverageTimeToEmpty() displays state-of-charge in formation in a more useful way. It averages the instan taneous estimations so the remaining time does not ap pear to jumparound.

SMBus Protocol: Read Word Output:

Unsigned integer — minutes of operation left. Units: minutes Range: 0to 65,534 min Granularity: 2min or better Accuracy: -0, +MaxError() ∗ FullChargeCapacity()

/ AverageCurrent() Invalid Data Indication: 65,535 indicates battery is

not being discharged.

AverageTimeToFull() (0x13);[0x13]

Description: Returns a one-minute rolling average of the predicted remaining time until the battery reaches full charge (minutes).

Purpose: The AverageTimeToFull() function can be used by the SMBus Host’s power management system to aid in its policy. It may also be used to find out how long the system must be left on to achieve full charge.

SMBus Protocol: Read Word Output:

Unsigned integer —remaining time in minutes. Units: minutes Range: 0to 65,534 minutes Granularity: 2minutes or better Accuracy: MaxError() ∗ FullChargeCapacity() /

AverageCurrent() Invalid Data Indication: 65,535 indicates the bat

tery is not being charged.

ChargingCurrent() (0x14); [0x14]

Description: Returnsthe desired charging rate in mA. Purpose: The ChargingCurrent() function sets the

maximum charge current of the battery. The ChargingCurrent() value should be used in combination with the ChargingVoltage() value to set the charger’s op erating point. Together, these functions permit the bq2060A to dynamically control the charging profile

(current/voltage) of the battery. The bq2060A can effec

tively turn off a charger by returning a value of 0 for this function. The charger may be operated as a con stant-voltage source above its maximum regulated cur rent range by returning a ChargingCurrent() value of

65,535.

SMBus Protocol: Read Word Output:

Unsigned integer—maximum charger output cur rent in mA.

Units: mA Range: 0to 65,535mA Granularity: 1mA Accuracy: notapplicable Invalid Data Indication: 65,535 indicates that a

charger should operate as a voltage source outside its maximum regulated current range.

ChargingVoltage()(0x15); [0x15]

Description: Returns the desired charging voltage in mV.

Purpose: The ChargingVoltage() function sets the max imum charge voltage of the battery. The ChargingVoltage() value should be used in combination with the ChargingCurrent() value to set the charger’s operating point. Together, these functions permit the bq2060A to dynamically control the charging profile (current/voltage) of the battery. The charger may be op erated as a constant-current source above its maximum regulated voltage range by returning a ChargingVoltage() value of 65,535.

SMBus Protocol: WriteWord Output:

Unsigned integer—charger output voltage in mV. Units: mV

Range: 0to 65,535mV Granularity: 1mV

bq2060A

Accuracy: notapplicable Invalid Data Indication: 65,535 indicates that the

charger should operate as a current source outside its maximum regulated voltage range.

BatteryStatus()(0x16); [0x16]

Description: Returns the bq2060’s status word (flags). Some of the BatteryStatus() flags (REMAINING_CA PACITY_ALARM and REMAINING_TIME_ALARM) are calculated based on either current or power depend ing on the setting of the BatteryMode()’s CAPAC ITY_MODE bit. This is important because use of the wrong calculation mode may result in an inaccurate alarm.

Purpose: The BatteryStatus() function is used by the power-management system to get alarm and status bits, as well as error codes from the bq2060A. This is basi cally the same information broadcast to both the SMBus Host and the Smart Battery Charger by the AlarmWarning() function except that the AlarmWarning() function sets the Error Code bits all high before sending the data.

SMBus Protocol: Read Word Output:

Unsigned integer—Status Register with alarm conditions bit mapped as follows:

Alarm Bits

0x8000 OVER_CHARGED_ALARM 0x4000 TERMINATE_CHARGE_ALARM 0x2000 reserved 0x1000 OVER_TEMP_ALARM 0x0800 TERMINATE_DISCHARGE_ALARM 0x0400 reserved 0x0200 REMAINING_CAPACITY_ALARM 0x0100 REMAINING_TIME_ALARM

Status Bits

0x0080 INITIALIZED 0x0040 DISCHARGING 0x0020 FULLY_CHARGED 0x0010 FULLY_DISCHARGED

Error Codes

0x0007 Unknown Error 0x0006 BadSize 0x0005 Overflow/Underflow 0x0004 AccessDenied 0x0003 UnsupportedCommand 0x0002 ReservedCommand 0x0001 Busy 0x0000 OK

Alarm Bits

OVER_CHARGED_ALARM bit is set whenever the bq2060A detects that the battery is being charged be yond the Maximum Overcharge limit. This bit is cleared when the bq2060A detects that the battery is no longer being charged (i.e., the bq2060A detects discharge activ ity or no activity for the digital filter timeout periods. The digital filter timeout period (seconds) equates to 10 time the value shared in Digital Filter EE0x52.)

TERMINATE_CHARGE_ALARM bit is set when the

bq2060A detects that one or more of the battery’s charg

ing parameters are out of range (e.g., its voltage, cur rent, or temperature is too high) or when the bq2060A detects a primary charge termination. This bit is cleared when the parameter falls back into the allow able range, the termination condition ceases, or when the bq2060A detects that the battery is no longer being charged.

OVER_TEMP_ALARM bit is set when the bq2060A de

tects that the internal battery temperature is greater than or equal to the MaxT limit. This bit is cleared when the internal temperature falls back into the acceptable range.

TERMINATE_DISCHARGE_ALARM bit is set when the bq2060A detects Voltage() ≤ EDV0, the CVUV bit in Pack Status is set (Li-Ion cell voltage has dropped below the limit programmed in Cell Under / Over Voltage),or RemainingCapacity() = 0. The bit is cleared when Voltage() > EDV0 or CVUV bit is cleared, and RemainingCapacity() > 0.

REMAINING_CAPACITY_ALARM bit is set when the bq2060A detects that RemainingCapacity() is less than that set by the RemainingCapacityAlarm() function. This bit is cleared when either the value set by the RemainingCapacityAlarm() function is lower than RemainingCapacity() or when the RemainingCapacity() is increased by charging.

REMAINING_TIME_ALARM bit is set when the bq2060A detects that the estimated remaining time at the present discharge rate is less than that set by the RemainingTimeAlarm() function. This bit is cleared when either the value set by the RemainingTimeAlarm() func tion is lower than the AverageT imeToEmpty() or when the AverageT imeToEmpty() is increased by charging.

Status Bits

INITIALIZED bit is set when the bq2060A is has de tected a valid load of EEPROM. It is cleared when the bq2060Adetects an improper EEPROM load.

DISCHARGING bit is set when the bq2060A deter mines that the battery is not being charged. This bit is cleared when the bq2060A detects that the battery is be ing charged.

bq2060A

FULLY_CHARGED bit is set when the bq2060A de tects a primary charge termination or an overcharged condition. It is cleared when RelativeStateOfCharge() ≤ the programmed Fully Charged Clear % in EE 0x4c.

FULLY_DISCHARGED bit is set when Voltage() ≤ EDV2 threshold, or RemainingCapacity() < Full Charge Capacity*BatteryLow%. This bit is cleared when the Relative StateOfCharge() is ≥ 20%.

Error Codes Description

Busy

Reserved

Unsupported

AccessDenied

Over/Underflow

BadSize

UnknownError

The bq2060A processed the function

code without detecting any errors.

The bq2060A is unable to process the

function code at this time.

The bq2060A detected an attempt to

read or write to a function code

reserved by this version of the

specification. The 2060 detected an

attempt to access an unsupported

optional manufacturer function code.

The bq2060A does not support this

function code which is defined in this

version of the specification.

The bq2060A detected an attempt to

write to a read-only function code.

The bq2060A detected a data overflow

or underflow.

The bq2060A detected an attempt to

write to a function code with an

incorrect data block.

The bq2060A detected an

unidentifiable error.

CycleCount()(0x17); [0x17]

Description: Returns the number of cycles the battery has experienced. The mAh value of each count is deter mined by programming the Cycle Count Threshold value in EE 0x3c–0x3d. The bq2060A saves the cycle count value to Cycle Count EE 0x0e–0x0f after an update to CycleCount().

Purpose: The CycleCount() function provides a means to determine the battery’s wear. It may be used to give advanced warning that the battery is nearing its end of life.

SMBus Protocol: Read Word Output:

Unsigned integer—count of total charge removed from the battery over its life.

Units: cycle Range: 0 to 65,534 cycles 65,535 indicates battery

has experienced 65,535 or more cycles.

Granularity: 1cycle Accuracy: absolutecount

DesignCapacity() (0x18); [0x18]

Description: Returns the theoretical or nominal capac ity of a new pack. The DesignCapacity() value is ex pressed in either current (mAh at a C/5 discharge rate) or power, (10mWh at a P/5 discharge rate) depending on the setting of the BatteryMode()’s CAPACITY_MODE bit.

Purpose: The DesignCapacity() function is used by the SMBus Host’s power management in conjunction with FullChargeCapacity() to determine battery wear. The power management system may present this informa tion to the user and also adjust its power policy as a re sult.

SMBus Protocol: Read Word Output:

Unsigned integer—battery capacity in mAh or 10mWh.

Battery Mode

CAPACITY_MODE

bit=0

Units mAh 10mWh

Range 0–65,535mAh 0–65,535 10mWh

Granularity Not applicable

Accuracy Not applicable

CAPACITY_MODE

bit=1

DesignVoltage()(0x19); [0x19]

Description: Returns the theoretical voltage of a new pack (mV). The bq2060A sets DesignVoltage() to the

value programmed in Design VoltageEE0x12–0x13. Purpose: The DesignVoltage() function can be used to

give additional information about a particular Smart Battery’sexpected terminal voltage.

SMBus Protocol: Read Word Output:

Unsigned integer—the battery’s designed terminal voltage in mV

Units: mV Range: 0to 65,535 mV Granularity: notapplicable Accuracy: notapplicable

bq2060A

SpecificationInfo() (0x1a); [0x1a]

Description: Returns the version number of the Smart Battery specification the battery pack supports, as well as voltage and current scaling information in a packed unsigned integer. Power scaling is the product of the voltage scaling times the current scaling. The SpecificationInfo is packed in the following fashion: (SpecID_H ∗ 0x10 + SpecID_L) + (VScale + IPScale∗ 0x10)∗ 0x100.

The bq2060A VScale (voltage scaling) and IPScale (cur rent scaling) should always be set to zero. The bq2060A sets SpecificationInfo() to the value programmed in Specification Information EE 0x14–0x15.

Purpose: The SpecificationInfo() function is used by the SMBus Host’s power management system to deter mine what information the Smart Battery can provide.

SMBus Protocol: Read Word Output:

Unsigned integer—packed specification number and scaling information.

Field

SpecID_L 0...3 SpecID_H 4...7

VScale 8...11

IPScale 12...15

Bits

Used Format Allowable Values

4-bit binary

value

4-bit binary

value

4-bit binary

value

4-bit binary

value

0–15 0–15

0 (multiplies voltage

by 10^ VScale)

0 (multiplies current

by 10 ^ IPScale)

ManufactureDate() (0x1b); [0x1b]

Description: This function returns the date the cell pack was manufactured in a packed integer. The date is packed in the following fashion: (year-1980) ∗ 512 + month ∗ 32 + day. The bq2060A sets ManufactureDate() to the value programmed in Manufacture Date EE 0x16–0x17.

Purpose: The ManufactureDate() provides the system with information that can be used to uniquely identify a particular battery pack when used in conjunction with SerialNumber().

SMBus Protocol: Read Word Output:

Unsigned integer—packed date of manufacture.

Field Bits Used Format Allowable Values

Day 0...4

Month 5...8

Year 9...15

5-bit binary

value

4-bit binary

value

7-bit binary

value

0–31 (corresponds to

date)

1–12 (corresponds to

month number)

0–127 (corresponds to

year biased by 1980)

SerialNumber() (0x1c); [0x1c]

Description: This function is used to return a serial

number. This number, when combined with the ManufacturerName(), the DeviceName(), and the ManufactureDate(), uniquely identifies the battery (un signed int). The bq2060A sets SerialNumber() to the value programmed in Serial Number EE 0x18–0x19.

Purpose: The SerialNumber() function can be used to

identify a particular battery. This may be important in

systems that are powered by multiple batteries where the system can log information about each battery that it encounters.

SMBus Protocol: Read Word Output:

Unsigned integer

ManufacturerName() (0x20); [0x20-0x25]

Description: This function returns a character array containing the battery’s manufacturer’s name. For example, MyBattCo would identify the Smart Battery’s manufacturer as MyBattCo. The bq2060A sets ManufacturerName() to the value programmed in Man ufacturer Name EE 0x20–0x2a.

Purpose: The ManufacturerName() function returns the name of the Smart Battery’s manufacturer. The manufacturer’s name can be displayed by the SMBus Host’s power management system display as both an identifier and as an advertisement for the manufac turer. The name is also useful as part of the informa tion required to uniquely identify a battery.

SMBus Protocol: Read Block Output:

String—character string with maximum length of 11characters (11+lengthbyte).

DeviceName() (0x21); [0x28-0x2b]

Description: This function returns a character string that contains the battery’s name. For example, a DeviceName() of BQ2060A would indicate that the battery is a model BQ2060A. The bq2060A sets DeviceName() to the value programmed in Device Name EE 0x30–0x37.

bq2060A

Purpose: The DeviceName() function returns the bat tery’sname for identification purposes.

SMBus Protocol: Read Block Output:

String—character string with maximum length of 7 characters (7+length byte).

DeviceChemistry() (0x22); [0x30-0x32]

Description: This function returns a character string that contains the battery’s chemistry. For example, if the DeviceChemistry() function returns NiMH, the battery pack would contain nickel metal hydride cells. The bq2060A sets DeviceChemistry() to the value programmed in Device Chemistry EE 0x40–0x44.

Purpose: The DeviceChemistry() function gives cell chemistry information for use by charging systems. The bq2060A does not use DeviceChemisty() values for inter nal charge control or fuel gauging.

SMBus Protocol: Read Block Output:

String—character string with maximum length of 4 characters (4+length byte).

Note: The following is a partial list of chemistries and their expected abbreviations. These abbreviations are NOT case sensitive.

Lead acid PbAc Lithium ion LION Nickel cadmium NiCd Nickel metal hydride NiMH Nickel zinc NiZn Rechargeable alkaline-manganese RAM Zinc air ZnAr

ManufacturerData() (0x23); [0x38–0x3a]

Description: This function allows access to the manu facturer data contained in the battery (data). The bq2060A stores seven critical operating parameters in this data area.

Purpose: The ManufacturerData() function may be used to access the manufacturer’s data area. The data fields of this command reflect the programming of five critical EEPROM locations and can be used to facilitate evaluation bq2060A under various programming sets. The ManufacturerData() function returns the following information in order: Control Mode, Digital Filter, Self-Discharge Rate, Battery Low %, Near Full, and the pending EDV threshold voltage (low byte and high byte.)

SMBus Protocol: Read Block

Output:

Block data—data that reflects EEPROM program ming as assigned by the manufacturer with maxi mum length of 7 characters (7+length byte).

Pack Status and Pack Configuration (0x2f); [0x2f]

This function returns the Pack Status and Pack Config uration registers. The Pack Status register contains a number of status bits relating to bq2060A operation. The Pack Status register is the least significant byte of the word. The Pack Configuration register is the most significant byte of the word. The byte reflects how the bq2060A is configured as defined by the value pro grammed in Pack Configuration in EE 0x3f.

The Pack Status Register consists of the following bits:

b7 b6 b5 b4 b3 b2 b1 b0

OCE EDV2 EINT VDQ COK DOK CVOV CVUV

OCE

The OCE bit indicates that offset cancellation is enabled. The bq2060A sets this bit after VFC offset calibration is complete.

0 Offset calibration is not enabled 1 Offset calibration is enabled

EDV2

The EDV2 bit indicates that Voltage() is less than the EDV2 threshold.

0 Voltage()> EDV2 threshold (discharging) 1

Voltage() ≤ EDV2 threshold

EINT

The EINT bit indicates that the VFC has detected a

charge or discharge pulse. 0 No charge/discharge activity detected 1 Charge/discharge activity detected.

VDQ

The VDQ bit indicates if the present discharge cycle is valid for an FCC update.

0 Discharge cycle is not valid 1 Discharge cycle is valid

bq2060A

COK

The COK bit indicates the status of the CFC pin of the bq2060A.

0 CFC pin is low 1 CFC pin is high

DOK

The DOK bit indicates the status of the DFC pin of the bq2060A.

0 DFC pin is low 1 DFC pin is high

CVOV

The CVOV bit indicates that a secondary Li-Ion protec tion limit has been exceeded. It is set if any individual cell exceeds the programmed high voltage limit, if the pack voltage exceeds the overvoltage threshold, or if an over temperature condition occurs. The bit is not latched and merely reflects the present overvoltage status.

0 No secondary protection limits exceeded 1 A secondary protection limit exceeded

CVUV

The CVUV bit indicates if any individual cell falls below the programmed low-voltage limit. The bit applies to lithium batteries only. The bit is not latched and merely reflects the present undervoltage status.

0 All series cells are above the low-voltage limit 1 A series cell is below the low voltage limit

VCELL4–VCELL1 (0x3c–0x3f); [0x3c–0x3f]

These functions return the calculated voltages in mV at the VCELL

through VCELL1inputs.

EEPROM

General

The bq2060A accesses the external EEPROM during a full reset and when storing historical data. During an EEPROM access, the V bq2060A uses the ESCL and ESDA pins to communicate with the EEPROM. The EEPROM stores basic configu ration information for use by the bq2060A. The EEPROM must be programmed correctly for proper bq2060Aoperation.

Memory Map

Table 9 shows the memory map for the EEPROM. It also contains example data for a 10 series NiMH and a 3s3p Li-Ion battery pack with a 0.05Ω sense resistor.

pin becomes active and the

OUT

EEPROM Programming

The following sections describes the function of each EEPROM location and how the data is to be stored.

Fundamental Parameters

Sense Resistor Value

Two factors are used to scale the current related mea surements. The 16-bit ADC Sense Resistor Gain value in EE 0x68–0x69 scales Current() to mA. Adjusting ADC Sense Resistor Gain from its nominal value pro vides a method to calibrate the current readings for sys tem errors and the sense resistor value (R nal value is set by

ADC Sense Resistor Gain=

The 16-bit VFC Sense Resistor Gain in EE 0x6a–0x6b scales each VFC interrupt to mAh. VFC Sense Resistor Gain is based on the resistance of the series sense resistor. The following formula computes a nominal or starting value for VFC Sense Resistor Gain from the sense resistor value.

VFC Sense Resistor Gain=

Sense resistor values are limited to the range of 0.00916 to 0.100Ω.

Digital Filter

The digital filter threshold, VDF (µV), is set by the value stored in Digital Filter EE 0x52.

Digital Filter=

2250 VDF

Cell Characteristics

Battery Pack Capacity and Voltage

Pack capacity in mAh units is stored in Pack Capacity EE 0x3a–0x3b. In mAh mode, the bq2060A copies Pack Capacity to DesignCapacity(). In mWh mode, the bq2060A multiplies Pack Capacity by Design Voltage EE

0x12–0x13 to calculate DesignCapacity() scaled to 10mWh. DesignVoltage is stored in mV.

The initial value for Last Measured Discharge in mAh is stored in EE 0x38–0x39. Last Measured Discharge is modified over the course of pack usage to reflect cell aging under the particular use conditions. The bq2060A updates Last Measured Discharge in mAh after a capacity learning cycle. The bq2060A uses the LastMeasuredDischarge value to calculate FullChargeCapacity() in mAh or 10mWh mode.

) . The nomi

625

(Rs)

409.6 (Rs)

(4)

(5)

(6)

bq2060A

Table 9. EEPROM Memory Map

EEPROM

Address Name Chemistry

0x00 0x01 0x02 0x03 0x04 0x05

0x06

0x07 0x08 Misc Options -0-000-00

0x09 0x0a 0x0b 0x0c 0x0d Reserved - 128 00 80 128 00 80 0x0e 0x0f 0x10 0x11 Reserved - 0 00 00 0 00 00 0x12 0x13 0x14 0x15 0x16 0x17 0x18 0x19 0x1a 0x1b

0x1c 0x1d 0x1e 0x1f

0x20 0x21 0x22 0x23 0x24 0x25 0x26 0x27 0x28 0x29 0x2a 0x2b 0x2c 0x2d Reserved - 0 00 00 0 00 00 0x2e 0x2f 0x30 0x31 0x32 0x33 0x34

(Continued on next page) Note: Reserved locations must be set as shown. Locationsmarked with an * are calibration values that canbe

Check Byte 1

Remaining Time Alarm

Remaining Capacity Alarm

EDV A0 Impedance Age

Factor

EDV TC Cold Impedance

Factor

Safety Overtemperature

Charging Voltage

Cycle Count

Design Voltage

Specification Information

Manufacture Date

Serial Number Fast-Charging Current Maintenance Charging

Current

Pre-Charge Current

Manufacturer Name Length

Character 1 Character 2 Character 3 Character 4 Character 5 Character 6 Character 7 Character 8 Character 9

Character 10

Light Discharge Current

Maximum Overcharge

Device Name Length

Character 1 Character 2 Character 3 Character 4

adjusted for maximum accuracy. For these locations thetable shows the appropriate default or initial

Li-Ion, Nickel 15487 3c 7f 15487 3c 7f Li-Ion, Nickel 10 minutes 00 0a 10 minutes 00 0a Li-Ion, Nickel 350mAh 01 5e 400mAh 01 90

Li-Ion, Nickel 0 - 00 0 - 00

-0-003-03

-0-000-00

Li-Ion, Nickel 18000mV 46 50 12600mV 31 38

Li-Ion, Nickel 0 00 00 0 00 00

Li-Ion, Nickel 12000mV 2e e0 10800mV 2a 30 Li-Ion, Nickel v1.1/PEC 00 31 v1.1/PEC 00 31 Li-Ion, Nickel 2/25/99=9817 26 59 2/25/99=9817 26 59 Li-Ion, Nickel 1 00 01 1 00 01 Li-Ion, Nickel 4000mA 0f a0 3000mA 0b b8

Li-Ion, Nickel 200mA 00 c8 0mA 00 00 Li-Ion, Nickel 800mA 03 20 100mA 00 64

Li-Ion, Nickel 9 - 09 9 - 09 Li-Ion, Nickel B - 42 B - 42 Li-Ion, Nickel E - 45 E - 45 Li-Ion, Nickel N - 4e N - 4e Li-Ion, Nickel C - 43 C - 43 Li-Ion, Nickel H - 48 H - 48 Li-Ion, Nickel M - 4d M - 4d Li-Ion, Nickel A - 41 A - 41 Li-Ion, Nickel R - 52 R - 52 Li-Ion, Nickel Q - 51 Q - 51 Li-Ion, Nickel 0 - 00 0 - 00 Li-Ion, Nickel 0 - 00 0 - 00

Li-Ion, Nickel 200mAh ff 38 256mAh ff 00 Li-Ion, Nickel 7 - 07 7 - 07 Li-Ion, Nickel B - 42 B - 42 Li-Ion, Nickel Q - 51 Q - 51 Li-Ion, Nickel 2 - 32 2 - 32 Li-Ion, Nickel 0 - 30 0 - 30

NiMH

Example

Data Li-Ion

MSB LSB MSB LSB

Example

Data

bq2060A

Table 9. EEPROM Memory Map (Continued)

EEPROM

Address Name Chemistry

0x35 0x36 0x37 0x38 0x39 Last Measured Discharge Li-Ion, Nickel 4000mAh 0f a0 4050mAh 0f d2 0x3a 0x3b 0x3c 0x3d 0x3e Reserved - 0 - 00 0 - 00

0x3f Pack Configuration Li-Ion, Nickel 232 - e8 246 - f6 0x40 Device Chemistry Length Li-Ion, Nickel 4 - 04 4 - 04 0x41 0x42 0x43 0x44 0x45 0x46 0x47 0x48 Overvoltage Margin Li-Ion, Nickel 0 - 00 800mV - 32 0x49 Overcurrent Margin Li-Ion, Nickel 512mA - 20 512mA - 20

0x4a 0x4b Fast Charge Termination % Li-Ion, Nickel 96% - a0 100% - 9c

0x4c Fully Charged Clear % Li-Ion, Nickel 90% - a6 95% - a1 0x4d Charge Efficiency Li-Ion, Nickel 97% - el 100% - ff

0x4e

0x4f 0x50 Manufacturers Data Length Li-Ion, Nickel 7 - 07 7 - 07

0x51 Control Mode Li-Ion, Nickel 4 04 4 04 0x52 Digital Filter Li-Ion, Nickel 0x53 0x54 BatteryLow % Li-Ion, Nickel 7% - 12 7% - 12 0x55 0x56 0x57 Reserved - 0 - 00 0 - 00 0x58 0x59 Reserved - 0 - 00 0 - 00 0x5a 0x5b Reserved - 0 - 00 0 - 00

Character 5 Character 6 Character 7

Pack Capacity

Cycle Count Threshold

Character 1 Character 2 Character 3 Character 4

MaxT DeltaT

Overload Current

Reserved Nickel 0 - 00 - - -

Cell Under/Over Voltage Li-Ion - - - 118 - 76

Current Taper Threshold Li-Ion - - - 200mA - 12

DeltaT Time

Holdoff Time

Current Taper Qual Voltage Li-Ion - - - 128mV - 40

Self-Discharge Rate

Near Full

Li-Ion, Nickel 6 - 36 6 - 36 Li-Ion, Nickel 0 - 30 0 - 30 Li-Ion, Nickel A - 41 A - 41

Li-Ion, Nickel 4000mAh 0f a0 4050mAh 0f d2 Li-Ion, Nickel 500mAh fe 0c 3240mAh f3 58

Li-Ion, Nickel N - 4e L - 4c Li-Ion, Nickel I - 49 I - 49 Li-Ion, Nickel M - 4d O - 4f Li-Ion, Nickel H - 48 N - 4e Li-Ion, Nickel 50C, 3.0 - c7 50C, 4.6 - cf Li-Ion, Nickel 6000mA 17 70 6000mA 17 70

Nickel 180s - 07 - - Nickel 240s - 04 - - -

Li-Ion, Nickel 1% - cb 0.21% - 05

Li-Ion, Nickel 200mAh - 64 200mAh - 64

NiMH

Example

50µV

Data Li-Ion

MSB LSB MSB LSB

-2d

Example

50µV

Data

-2d

(Continued on next page) Note: Reserved locations must be set as shown. Locations marked with an * are calibration values that can be

adjusted for maximum accuracy. For these locations the table shows the appropriate default or initial setting.

bq2060A

Table 9. EEPROM Memory Map (Continued)

EEPROM

Address Description Chemistry

0x5c 0x5d Reserved - 0 00 00 0 00 00

0x5e 0x5f VFC Offset* Li-Ion, Nickel 0 00 00 0 00 00 0x60 VFC Offset* Li-Ion, Nickel 0 - 00 0 - 00 0x61 Temperature Offset* Li-Ion, Nickel 0 - 00 0 - 00 0x62 ADC Offset* Li-Ion, Nickel 0 - 00 0 - 00

Cell 2 Calibration Factor* Li-Ion - - - 0 - 00

0x63

0x64

0x65 0x66 0x67 ADC Voltage Gain* Li-Ion, Nickel 16 : 1 4e 20 16 : 1 4e 20

0x68 0x69 ADC Sense Resistor Gain* Li-Ion, Nickel 0x6a 0x6b VFC Sense Resistor Gain* Li-Ion, Nickel

0x6c 0x6d VOC 25% Li-Ion, Nickel 11500mV d3 14 10550mV d6 ca

0x6e 0x6f VOC 50% Li-Ion, Nickel 12500mV cf 2c 10750mV d6 02 0x70 0x71 VOC 75% Li-Ion, Nickel 13500mV cb 44 11200mV d4 40 0x72 0x73 EDVF/EDV0 Li-Ion, Nickel 9500mV 25 1c 10265mV 28 19 0x74 0x75 EMF/ EDV1 Li-Ion, Nickel 10000mV 27 10 11550 2d 1e 0x76 0x77 EDV T0 Factor Li-Ion, Nickel 0 00 00 4475 11 7b

0x78 0x79 EDV C1/C0 Factor/EDV2 Li-Ion, Nickel 10500mV 29 04 0x7a 0x7b EDV R0 Factor Li-Ion, Nickel 0 00 00 5350 14 e6

0x7c 0x7d EDV R1 Factor Li-Ion, Nickel 0 - 00 250 00 fa

0x7e 0x7f Check Byte 2 Li-Ion, Nickel 42330 a5 5a 42330 a5 5a

Efficiency Temperature

Compensation

Cell 3 Calibration Factor* Li-Ion - - - 0 - 00

Efficiency Drop Off

Percentage Cell 4 Calibration Factor* Li-Ion - - - 0 - 00 Efficiency Reduction Rate Nickel 1% - 50 - - -

Nickel 0.25% - 20 - - -

Nickel 96% - a0 - - -

NiMH

Example

0.05Ω

Data Li-Ion

MSB LSB MSB LSB

30 d4 20 00

Example

0.05Ω

C1=0

C0 = 235

Data

30 d4 20 00

00 eb

Note: Reserved locations must be set as shown. Locations marked with an * are calibration values that can be adjusted

for maximum accuracy.For these locations the table shows the appropriate default or initialsetting.

bq2060A

EDV Thresholds and Near FullPercentage

The bq2060A uses three pack voltage thresholds to pro vide voltage-based warnings of low battery capacity. The bq2060A uses the values stored in EEPROM for the EDV0, EDV1, and EDV2 values or calculates the three thresholds from a base value and the temperature, ca pacity, and rate adjustment factors stored in EEPROM. If EDV compensation is disabled then EDV0, EDV1, andEDV2 are stored directly in mV in EE 0x72–0x73, EE 0x74–0x75, and EE 0x78–0x79, respectively.

For capacity correction at EDV2, Battery Low % EE 0x54 can be set at a desired state-of-charge, STATEOFCHARGE%, in the range of 5 to 20%. Typical values for STATEOFCHARGE% are 7–12% representing 7 –12% capacity.

Battery Low % = STATEOFCHARGE% ∗ 2.56

(7)

The bq2060A updates FCC if a qualified discharge oc curs from a near-full threshold to EDV2. The desired near-full threshold window, NFW (mAh), is programmed in Near Full inEE 0x55.

Near Full =

NFW

(8)

EDV Discharge Rate and Temperature Compensation

If EDV compensation is enabled, the bq2060A calculates battery voltage to determine EDV0, EDV1, and EDV2 thresholds as a function of battery capacity, temperature, and discharge load. (See Figures 7 and 8.) The general equation for EDV0, EDV1, and EDV2 calculation is

(9)

EDV0,1,2 = EMF ∗ F

where

EMF is a no-load battery voltage that is higher than the highest EDV threshold that is computed. EMF is programmed in mV in EMF/EDV1 EE 0x74–0x75.

is the current discharge load.

LOAD

is the factor that adjusts the EDV voltage for bat

tery capacity and temperature to match the no-load characteristics of the battery.

where C (0%, 3%, or Battery Low % for EDV0, EDV1, and EDV2, respectively) and C0 are the capacity related EDV adjustment factors. C0 is programmed in the lower 11bits of EDV C0 Factor/EDV2 EE 0x78–79.

The Residual Capacity Factor is stored in the upper 5 bits of EE 0x78–0x79.

-|I

| ∗ R0 ∗ FTZ∗ F

LOAD

= f ( C0, C + C1, T ) (10)

Residual Capacity Factor C1=*RESIDUAL%.256

RESIDUAL % is the desired battery capacity remaining

at EDV0 (RM = 0).

T is the current temperature in °K

R0 ∗ F

represents the resistance of the battery as a

function of temperature and capacity.

=f(R1,T0,T,C+C1,TC) (11)

R0 is the first order rate dependency factor stored in

EDV R0 FactorEE 0x7a–0x7b. T is the current temperature; C is the battery

capacity relating to EDV0, EDV1, and EDV2; and C1 is the desired residual battery capacity remaining at EDV0 (RM = 0).

R1 adjusts the variation of impedance with battery

capacity. R1 is programmed in EDV R1 Rate Factor EE 0x7c–0x7d.

T0 adjusts the variation of impedance with battery

temperature. T0 is programmed in EDV T0 Rate Factor EE 0x76–0x77.

TC adjusts the variation of impedance for cold

temperature (T < 23°C). TC is programmed in EDV TC EE 0x07.

is the factor that adjusts for changing cell imped-

ance as the battery pack is cycled:

= f(A0, CycleCount()) (12)

where A0 is the EDV aging factor that is stored in EDV A0 Factor EE 0x06. It should be set to 0 for most appli cations.

Typical values for the EDV compensation factors for a Li-Ion 3s3p 18650 pack are

EMF = 11550 T0 = 4475 C0 = 235

C1=0 R0 = 5350 R1 = 250 A0=0 TC=3

The graphs in Figures 7 and 8 show the calculated EDV0, EDV1, and EDV2 thresholds versus capacity us ing the typical compensation values for different temperatures and loads for a Li-Ion 3s3p 18650 pack. The compensation values vary widely for different cell

bq2060A

types and manufacturers and must be matched exactly to the unique characteristics for optimal performance.

Overload Current Threshold

The Overload Current threshold is a 16-bit value stored in EE 0x46-0x47 in mAunits.

Midrange Capacity Corrections

Three voltage-based thresholds, VOC25 EE 0x6c–0x6d, VOC50 EE 0x6e–0x6f, and VOC75 EE 0x70–0x71, are

used to test the accuracy of the RM based on open-circuit pack voltages. These thresholds are stored in the EEPROM in 2’s complement of voltage in mV. The values represent the open-circuit battery voltage at which the battery capacity should correspond to the as sociated state of charge for each threshold.

Self-Discharge Rate

The nominal self-discharge rate, %PERDAY (% per day), is programmed in an 8-bit value Self-Discharge Rate EE 0x53 by the following relation:

52.73

Self Discharge Rate-=

256 -

ç è

%PERDAY

(13)

÷ ø

Light Load Current

The amount of light load current in mA, ILEAK, used for compensation is stored in Light Discharge Current in EE 0x2b as follows:

ILEAK 1024

Light Disch Current =

ILEAK is between 0.044 and 11.2mA.

arge

(14)

Charge Efficiency

The bq2060A uses four charge-efficiency factors to com pensate for charge acceptance. These factors are coded in Charge Efficiency, Efficiency Reduction Rate, Effi

ciency Drop Off Percentage, and Efficiency Temperature Compensation.

The bq2060A applies the efficiency factor, EFF%, when RelativeStateOfCharge() is less than the value coded in Efficiency Drop Off Percentage EE 0x64. When RelativeStateOfCharge() is greater than or equal to the value coded in Efficiency Drop Off Percentage, EFF% and ERR% determine the charge efficiency rate. ERR% defines the percent efficiency reduction per percentage point of RelativeStateOfCharge() over Efficiency Drop

Off Percentage. EFF% is encoded in High Charge Efficiency EE 0x4d according to the following equation:

Charge Efficiency =10∗ (EFF% - 74.5)

where

74.5 ≤ EFF% ≤100

ERR% is encoded in Efficiency Reduction Rate EE 0x65 according to the following equation:

Efficiency Reduction Rate =

where

0 ≤ ERR% ≤ 3.19

The Efficiency Drop Off Percentage is stored in 2’s com plement of percent.

The bq2060A also adjusts the efficiency factors for tem perature. TEFF% defines the percent efficiency reduc tion per degree C over 25°C. TEFF% is encoded in Effi ciency Temperature Compensation EE 0x63 according to the following equation

Efficiency Temperature Compensation =

where

0 ≤ TEFF% ≤1.99

The bq2060A applies all four charge-compensation factors when the CHEM bit in Pack Configuration is not set denoting a nickel pack.

Effective Charge Efficiency Reduction (nickel only)

= ERR%[RSOC() – EFF%] + TEFF%[T(°C) – 25]

where

If CHEM is set denoting a Li-Ion pack, the bq2060A ap plies only the value coded in High Charge Efficiency and

makes no other adjustments for charge acceptance.

RSOC() ≥ EFF% and T ≥ 25°C

ERR%

0.0125

TEFF% 1.6

0.0125

Charge Limits and Termination Techniques

Charging Voltage

The 16-bit value, Charging Voltage EE 0x0a-0x0b pro grams the ChargingVoltage() value broadcast to a Smart Charger. It is also sets the base value for determining overvoltage conditions during charging and voltage com pliance during a constant-voltage charging methodology. It is stored in mV.

(15)

(16)

(17)

(18)

bq2060A

11500

11000

10500

10000

Voltage (mV)

EDV2

EDV1

9500 9000 8500 8000 7500

Battery Low % = 7%, Load = 500mA

45C/500mA 20C/500mA

109876543210

% Capacity

Figure 7. EDV Calculations vs. Capacity

for Various Temperatures

Overvoltage

The 8-bit value, Overvoltage Margin EE 0x48, sets the limit over ChargingVoltage() that is to be considered as an overvoltage charge-suspension condition. The voltage in mV above the ChargingVoltage(), VOVM, that should trigger a charge suspend is encoded in

Overvoltage Margin as follows:

Overvoltage Margin=

VOVM

(19)

VOVM is between 0 and 4080mV.

Charging Current

ChargingCurrent() values are either broadcast to a Level 2 Smart Battery Charger or read from the bq2060A by a Level 3 Smart Battery Charger. The bq2060A sets the value of ChargingCurrent(), depending on the charge requirements and charge conditions of the pack.

When fast charge is allowed, the bq2060A sets ChargingCurrent() to the rate programmed in Fast Charging Current EE 0x1a-0x1b.

When fast charge terminates, the bq2060A sets ChargingCurrent() to zero and then to the Maintenance Charging Current EE 0x1c-0x1d when the termination condition ceases.

When Voltage() is less than EDV0, the bq2060A sets ChargingCurrent() to Pre-charge Current EE 0x1e-0x1f. Typically this rate is larger than the maintenance rate to charge a deeply depleted pack up to the point where it may be fast charged.

Battery Low % =7%, Temperature = 35 C

11500 11000

EDV2

10500

EDV1

10000

9500 9000

Voltage (mV)

8500 8000

7500

EDV0

7000

109876543210

35C/500mA 35C/1A

35C/2A

% Capacity

Figure 8. EDV Calculations vs. Capacity

for Various Loads

Fast Charging Current, Maintenance Charging Current, and Pre-Charge Current are stored in mA.

Charge Suspension

During charge, the bq2060A compares the current to the ChargingCurrent() plus the value IOIM. If the pack is charged at a current above the ChargingCurrent() plus IOIM, the bq2060A sets ChargingCurrent() to zero to stop charging. IOIM is programmed in the EEPROM value, Overcurrent Margin, encoded as follows:

Overcurrent Margin=

IOIM

Overcurrent Margin EE 0x49 may be used to program IOIM values of 0 to 4080mAin 16mAsteps.

The desired temperature threshold for charge suspen sion, MAXTEMP, may be programmed between 45°C and 69°C in 1.6°C steps. Charge-suspension tempera ture is increased by 16° above the programmed value of bit5inMiscellaneous Option EE 0x08 is set. MaxT DeltaT EE 0x45 (most significant nibble) is stored in a 4-bit value as shown:

MaxT=

é ê

1.6

ù ú

69 MAXTEMP

The bq2060A suspends fast charge when fast charge continues past full by the amount programmed in Maxi mum Overcharge EE 0x2e-0x2f. Maximum Overcharge is programmed in 2s complement form of charge in mAh.

(20)

(21)

bq2060A

FULLY_CHARGED Bit ClearThreshold

The bq2060A clears the FULLY_CHARGED bit in BatteryStatus() when RelativeStateOfCharge() reaches the value, Fully Charged Clear % EE 0x4c. Fully Charged Clear % is an 8-bit value and is stored as a 2’s complement of percent.

Fast Charge Termination Percentage

The bq2060A sets RM to a percentage of FCC on charge termination if the CSYNC bit is set in the Pack Configu ration register. The percentage of FCC is stored in Fast Charge Termination % in EE 0x4b. The value is stored in 2’scomplement of percent.

Cycle Count Threshold

Cycle Count Threshold 0x3c–0x3d sets the number of mAh that must be removed from the battery to incre ment CycleCount(). Cycle Count Threshold is a 16-bit value stored in 2’scomplement of charge in mAh.

∆T/Dt Rate Programming

The ∆T portion of the ∆T/∆t rate is programmed in

DeltaT, the low nibble of MaxT DeltaT EE 0x45 (least significant nibble). The ∆t portion is programmed in DeltaT TimeEE 0x4e.

[]

DeltaT

216

/100°

∆T/∆t=

[]

DeltaT Time

320- 2Cs

DeltaT D(°C) DeltaT_Time

0 1.6 00 320 1 1.8 01 300 2 2.0 02 280 3 2.2 03 260 4 2.4 04 240 5 2.6 05 220 6 2.8 06 200 7 3.0 07 180 8 3.2 08 160 9 3.4 09 140 a 3.6 0a 120 b 3.8 0b 100 c 4.0 0c 80 d 4.2 0d 60 e 4.4 0e 40

f 4.6 0f 20

(22)

t (s)

DT/Dt Hold-off Timer Programming

The hold-off timer is programmed in the lower nibble of Holdoff Time EE 0x4f. The hold-off time is 320s minus 20 times the HoldoffTimevalue.

Hold-off

Time

00 320 08 160 01 300 09 140 02 280 0a 120 03 260 0b 100 04 240 0c 80 05 220 0d 60

06 200 0e 40 07 180 0f 20

Hold-off Time (s)

Hold-off

Time

Hold-off Time (s)

Current TaperTerminationCharacteristics

Two factors in the EEPROM set the current taper termi nation for Li-Ion battery packs. The two coded locations are Current Taper Qual Voltage EE 0x4f and Current

Taper Threshold EE 0x4e. Current taper termination oc curs during charging when the pack voltage is above the charging voltage minus CELLV (mV) and the charging current is below the threshold coded in Current Taper

Threshold forat least 80s.

Current Taper Qual Voltage =

Current Taper Threshold =

where i = the desired current termination threshold in mA, and R

= VFC sense resistor in ohms.

CELLV

0.5625

Pack Options

Pack Configuration

Pack Configuration EE 0x3f contains bit-programmable features.

b7 b6 b5 b4

SEAL

DMODE

CSYNC CEDV VCOR CHEM LCC1 LCC0

DMODE

The DMODE bit determines whether the LED outputs will indicate AbsoluteStateOfCharge() or RelativeStateOfCharge()

0 LEDs reflect AbsoluteStateOfCharge() 1 LEDs reflect RelativeStateOfCharge()

b3 b2 b1 b0

(23)

(24)

bq2060A

SEAL

The SEAL bit determines the SMBus access state of the bq2060Aon reset

0 SMBus commands (0x00–0xff) are accessible for

both read and write.

1 SMBus read access is limited to commands

(0x05–0x1c) and (0x20–0x23). SMBus read/write access is limited to commands (0x00–0x04), (0x2f), and (0x3c–0x3f).

CSYNC

In usual operation of the bq2060A, the CSYNC bit is set so that the coulomb counter is adjusted when a fast charge termination is detected. In some applications, es pecially those where an externally controlled charger is used, it may be desirable NOT to adjust the coulomb counter.In these cases the CSYNC bit should be cleared.

0 The bq2060A does not alter RM at the time of a

valid charge termination.

1 The bq2060A updates RM with a programmed per-

centage of FCC at a valid charge termination.

CEDV

The CEDV bit determines whether the bq2060A implements automatic EDV compensation to calculate the EDV0, EDV1 and EDV2 thresholds base on rate, temperature, and capacity. If reset, the bq2060A uses the fixed values programmed in EEPROM for EDV0, EDV1 and EDV2. If set the bq2060A calculates EDV0, EDV1 and EDV2.

0 EDV compensation disabled 1 EDV compensation enabled

VCOR

The VCOR bit enables the midrange voltage correction algorithm. When set, the bq2060A compares the pack voltage to RM and may adjust RM according to the val ues programmed in VOC25, VOC50, and VOC75.

0 Midrange corrections disabled 1 Midrange corrections enabled

CHEM

The CHEM bit configures the bq2060A for nickel packs (NiCd or NiMH) or Li-Ion packs. When set the bq2060A employs the configuration parameters in EEPROM des ignated for Li-Ion. When not set, the bq2060A employs the configuration parameters designated for nickel.

0 The bq2060A uses nickel configuration parameters. 1 The bq2060A uses Li-Ion configuration parameters.

LCC0 and LCC1

The LCC0 and LCC1 bits configure the cell voltage in puts (VCELL

No. of Series

Cells LCC1 LCC0

1–4

Cell Voltage

NA 00 VCELL

201

VCELL VCELL

VCELL

310

VCELL VCELL

VCELL

411

VCELL VCELL VCELL

Inputs

= Cell Stack

= Cell 1

= Cell 2

= Cell 1

= Cell 2

= Cell 3

= Cell 1

= Cell 2

= Cell 3

= Cell 4

For Li-Ion packs with individual measurements, LCC0 and LCC1 define the number of series elements and their voltage measurement inputs. In each case (2, 3, or

4), the bq2060A uses the highest numbered cell voltage input to measure the pack voltage measurement as returned with Voltage(). For nickel chemistries or Li-Ion without single-cell measurements, LCC0 and LCC1 must be set to 00. VCELL

is the pack voltage input for

this programming.

Remaining Time andCapacity Alarms

Remaining Time Alarm in EE 0x02–0x03 and Remaining Capacity Alarm in 0x04–0x05set the alarm

thresholds used in the SMBus command codes 0x01 and 0x02, respectively. Remaining Time Alarm is stored in minutes and Remaining Capacity Alarm in mAh.

Secondary Protection Limits for Li-Ion

The cell undervoltage (VUV) and overvoltage (VOV) limits are programmed in Cell Undervoltage/Over Voltage EE 0x4a according to the equations:

V -4096

Cell Undervoltage/Overvoltage (lower) =

Cell Undervoltage/Overvoltage (upper) =

V 2048

UV -

(25)

(26)

bq2060A

Cell Under/Over

Voltage

(upper nibble)

0 2048 0 4096 1 2112 1 4128 2 2176 2 4160 3 2240 3 4192 4 2304 4 4224 5 2368 5 4256 6 2432 6 4288 7 2496 7 4320 8 2560 8 4352 9 2624 9 4384 a 2688 a 4416 b 2752 b 4448 c 2816 c 4480 d 2880 d 4512 e 2944 e 4544 f 3008 f 4576

Safety Overtemperature EE 0x09 sets Safety Overtemperature Threshold (SOT) level for the CFC pin. It can be programmed for a threshold of 69° to 85°C. This range is increased by 16° if Miscellaneous Options bit5=1.

SafetyOvertemperature SOT=- *(. )945 10

if Miscellaneous Options bit5=0.

SafetyOvertemperature SOT=-*(. )1105 10

if Miscellaneous Options bit5=1.

(mV)

Cell Under/Over

Voltage

(lower nibble)

(mV)

Miscellaneous Options

Miscellaneous Options EE 0x08 contains bit-programmable options. Bits 0–4 should be pro grammed to zero.

HIT

The HIT bit controls the available temperature range for maximum temperature.

Maximum temperature set in normal 45–85°C range

1 Maximum temperature set in elevated 61–85°C

range

Cycle Count Initialization

Cycle Count EE 0x0e–0x0f stores the initial value for the CycleCount() function. It should be programmed to 0x0000.

Control Modes

Control Mode EE0x51 contains additional bit program mable features.

b7 b6 b5 b4 b3 b2 b1 b0

NDF - HPE CPE LED SC - SM

NDF

The NDF bit disables the digital filter during discharge if the SMBC and SMBD lines are high.

0 Digital filter enabled all the time 1 Digital filter disabled if SMBC and SMBD are high

HPE

The HPE bit enables/disables PEC transmissions to the Smart Battery host for master mode alarm messages.

0 No PEC byte on alarm warning to host

1 PEC byte on alarm warning to host

b7 b6 b5 b4 b3 b2 b1 b0

NE1 SOT HIT 0 0 0 0 0

NE1

The NE1 bit disables the EDV1 threshold. 0 EDV1 enabled 1 EDV1 disabled

SOT

The SOT bit controls override of the CFC pin for Safety Overtemperature threshold.

0 CFC control with overvoltage, maximum tempera

ture, and safety overtemperature.

1 CFC control; only with safety overtemperature.

CPE

The CPE bit enables/disables PEC transmissions to the Smart Battery Charger for master mode alarm mes sages.

0 No PEC byte on broadcasts to charger 1 PEC byte on broadcasts to charger

LED

The LED bit configures the bq2060A for 4 or 5 LED indi cation

0 Selects the 5 LED indication mode

1 Selects the 4 LED indication mode

bq2060A

The SC bit enables learning cycle optimization for a Smart Charger or independent charge

0 Learning cycle optimized for independent charger 1 Learning cycle optimized for Smart Charger

The SM bit enables/disables master mode broadcasts by the bq2060A

0 Broadcasts to host and charger enabled 1 Broadcasts to host and charger disabled If the SM bit is set, modifications to bits in

BatteryMode() will not re-enable broadcasts.

Measurement Calibration

ADC

To describe how the bq2060A calculates reported battery and individual cell voltages, the following abbreviations and designations are used:

VCELL bq2060A

VCELL1–4 = reported cell voltages Vnl–4 = voltages at the different series nodes in the

battery Voltage() = reported battery voltage V

= voltage across the sense resistor

The reported voltages measurements, Voltage() and VCELL1–4, may be calibrated by adjusting five 8- or 16-bit registers in EEPROM: ADC Offset in EE0x62,

ADC Voltage Gain in EE 0x66–0x67, Cell 2 Calibration Factor in EE 0x63, Cell 3 Calibration Factor in EE 0x64,

and Cell 4 Calibration Factor in EE 0x65. The bq2060A first computes the node voltages Vnl, Vn2,

Vn3, and Vn4. The node voltages are inputs to the volt age dividers to the VCELL of the bq2060A. The bq2060A computes node voltages to calculate the five reported voltages by the bq2060A: Voltage(), VCELL1, VCELL2, VCELL3, and VCELL4.

An ADC Voltage Gain factor of 20,000 is the nominal value when using the recommended cell-voltage division ratios of 16:1 on the VCELL 8:1 on the VCELL subtracts the voltage across the sense resistor from the measurements so that the reported voltages reflect the cell-stack voltages only.

= voltages at the input pins of the

1–4

through VCELL4input pins

and VCELL3inputs and

and VCELL1inputs. The bq2060A

The bq2060Acompute the node voltages as follows:

ê ë

Vn2

Vn3

ê ë

[]

é ê

Vn4

ê ë

[]

é ê

VCELL

é ê

VCELL

ADC Voltage Gai

65536

VCELL

ADC Voltage Gai

65536

32768

1250

VCELL

32768

1250

ADC Voltage Gai

32768

1250

ú û

32768

1250

ú û

ADC Offset

n Cell CalibrationFactor+*

ADC Offset

n Cell CalibrationFactor+* *

ADC Offset

n Cell CalibrationFactor+* *

ADC Voltage Gai

*ADC Offset

()

65536

ù ú

()3

ú û

()4

65536

ú û

Note: With LCC1-LCC0 = 00, Cell 4 Calibration Factor =0.

ADC Offset adjusts the ADC reading for voltage and cur

rent measurements. ADC Offset is a signed 8-bit value that cancels offset present in the circuit with no poten tial or current flow. ADC Offset is typically set between

-20 and 20. The bq2060A uses the computed node voltages to calcu

late the reported voltages. It does not compute reported cell voltages greater than the selected number of nodes. If no individual cell voltages are to be measured, LCC1–LCC0 should be set to 00 and the top of the bat tery stack should be connected to a voltage divider to

the VCELL

input.

The bq2060Acomputes the reported voltages as follows:

Voltage() = Vn4 (LCC1–LCC0 = 11or 00) - V Voltage() = Vn3 (LCC1–LCC0 = 10) - V Voltage() = Vn2 (LCC1–LCC0 = 01) - V

VCELL4 = Vn4 - Vn3 VCELL3 = Vn3 - Vn2 VCELL2 = Vn2 - Vn1 VCELL1 = Vn1 - V

(27)

ú û

(28)

ù ú

(29)

(30)

bq2060A

Current

The bq2060A scales Current() to mA units by the 16-bit value ADC Sense Resistor Gain in EE 0x68–0x69. Adjusting ADC Sense Resistor Gain from its nominal value provides a method to calibrate the current read ings for variances in the ADC gain, internal voltage ref erence, and sense resistor value. The bq2060A calculates Current() by

Current() =

[]

(ADC Reading + )

The nominal value for ADC Sense Resistor Gain is given by equation (6).

ADC Offset ADC Sense Resistor Gain*

,384

VFC

To calibrate the coulomb counting measurement for VFC gain errors and sense resistor tolerance, the value of VFC Sense Resistor Gain EE 0x6a-0x6b may be adjusted from its nominal value.

The nominal value of VFC Sense Resistor Gain is given by equation (5).

The bq2060A VFC circuit can introduce a signal opposite in sign from that of the inherent device and circuit offset to cancel this error. The offset calibration routine is initiated with commands to ManufacturerAccess().

The bq2060A calculates the offset with the calibration routine and stores the calibration value using the least 21 bits of VFC Offset in EE 0x5e–0x60.

The least 20 bits store the offset calibration value (OCV). The sign of the offset calibration value is positive if the 21st bit is 0.

OCV =

0.6V

VFC Offset

u 19 0–

Temperature

The bq2060A uses Temperature Offset in EE 0x61 to cali brate the Temperature() function for offset. The required offset adjustment, TOFF (C), sets Temperature Offset ac cording to the equation

Temperature Offset = TOFF

where

-12.8 ≤ TOFF ≤12.7

10 (33)

Constants and String Data

EEPROM Constants

Check/Byte 1 EE 0x00–0x01 and Check Byte 2 EE 0x7e–0x7f must be programmed to 0x3c7f and 0xa55a,

respectively.

Specification Information

Specification Information EE 0x14–0x15 stores the de

(31)

fault value for the SpecificationInfo() function. It is stored in EEPROM in the same format as the data re turned by the SepcificationInfo().

Manufacture Date

Manufacture Date EE 0x16–0x17 stores the default value for the ManufactureDate() function. It is stored in EEPROM in the same format as the data returned by the ManufactureDate().

Serial Number

Serial Number EE 0x18–0x19 stores the default value for the SerialNumber() function. It is stored in EEPROM in the same format as the data returned by the SerialNumber().

Manufacturer Name Data

Manufacturer Name Length EE 0x20 stores the length of the desired string that is returned by the ManufacturerName() function. Locations EE 0x21–0x2a store the characters for ManufacturerName() in ASCII code.Device Name Data

Device Name Length EE 0x30 stores the length of the desired string that is returned by the DeviceName() function. Locations EE 0x31–0x37 store the characters for DeviceName() in ASCII code.

Device Chemistry Data

(32)

Device Chemistry Length EE 0x40 stores the length of the desired string that is returned by the DeviceChemistry() function. Locations EE 0x41–0x44 store the characters for DeviceChemistry() in ASCII code.

Manufacturers Data Length

Manufacturers Data Length EE 0x50 stores the length

of the desired number of bytes that is returned by the ManufacturersData() function. It should be set to 7.

bq2060A

Absolute Maximum Ratings

Symbol Parameter Minimum Maximum Unit Notes

—Supply voltage Relative to V

–All other pins Relative to V

OPR

Operating

temperature

SS SS

Note: Permanent device damage may occur if Absolute Maximum Ratings are exceeded. Functional operation

should be limited to the Recommended DC Operating Conditions detailed in this data sheet. Exposure to conditions beyond the operational limits for extended periods of time may affect device reliability.

-0.3 +6.0 V

-20 +70 °C Commercial

DC Electrical Characteristics (VCC=2.7–3.7V, T

Symbol

SLP

LVOUT

VOUT

OLS

ILS

IHS

RBI

AI1

AI2

Low-power storage mode current

Output voltage low: LED1–LED5, CFC,

Output voltage low: THON, CVON I

Output voltage low SMBC, SMBD,

Input voltage low SMBC, SMBD,

Input voltage high SMBC, SMBD,

Input voltage range VCELL

RBI data-retention input current V

Input impedance: SR1, SR2 0–1.25V 10

Input impedance: VCELL

Parameter Conditions Minimum Typical Maximum Unit

Supply voltage 2.7 3.3 3.7 V

Operating current

OUT

1.5V < V

leakage current V

OUT

source current

OUT

DFC

OUT

OUT=VCC

OLS

Input voltage low DISP -0.3 0.8 V

Input voltage high DISP 2.0 VCC+ 0.3 V

= 1.0mA

HDQ16, ESCL, ESDA

, TS,

1–4

SRC

> 3.0V,VCC< 2.0V 10 50 nA

RBI

RBI data-retention voltage 1.3 V

, TS, SRC

1–4

0–1.25V 5

= -20–70°C, Unless Otherwise Noted)

OPR

inactive

< 3.7V

inactive

active,

- 0.6V = 5mA = 5mA 0.36 V

Note: ZAIspecifications are reference numbers based on process data.

180 235

510

-0.2 0.2

-5.0 mA

0.4 V

-0.3 0.8 V

1.7 6.0 V

- 0.3

1.25 V

µA µA µA

MΩ MΩ

bq2060A

VFC Characteristics (V

= 3.1–3.5V, T

= 0–70°C Unless Otherwise Noted))

OPR

Symbol Parameter Conditions Minimum Typical Maximum Unit

Input voltage range, V

SROS

SRCOS

VCO

TCO

INL

Note: RM

TCO

and V

SR1

VSRinput offset

Calibrated offset –16 +16

Supply voltage gain

coefficient (see Note)

Temperature gain

coefficient (see note)

Integral nonlinearity

error

total deviation is from the nominal gain at 25°C.

REG Characteristics (T

SR2

Slope for T

Total Deviation T

Slope for T

Total Deviation T

= -20–70°C)

OPR

VSR=V

SR2=VSR1

disabled

OPR

SR2–VSR1

, autocorrection

= 3.3V

= –20 to 70°C

OPR

= –20 to 70°C

OPR

=–0to50°C

OPR

=–0to50°C

OPR

= 0–50C

–0.25 +0.25 V

–250 –50 250

µV µ

0.8 1.2 %/V

–0.09 +0.09 %/°C

–1.6 0.1 %

–0.05 +0.05 %/°C

–0.6 0.1 %

0.21 %

Symbol Parameter Conditions Minimum Typical Maximum Unit

REG controlled output voltage

REG

REG output current 1.0

JFET: R

(on) < 150Ω

(off) < –3.0V @ 10µA

3.1 3.3 3.5 V

bq2060A

SMBus AC Specifications (VCC=2.7–3.7V, T

= -20–70°C, Unless Otherwise Noted)

OPR

Symbol Parameter Conditions Min. Typ. Max. Unit

SMB

MAS

BUF

HD:STA

SU:STA

SU:STO

HD:DAT

SU:DAT

TIMEOUT

LOW

HIGH

LOW:SEXT

LOW:MEXT

Notes: 1. The bq2060A will time out when any clock low exceeds T

SMBus operating frequency Slave mode, SMBC 50% duty cycle 10 100 kHz

SMBus master clock frequency

Bus free time between start and

stop

Master mode, no clock low slave

extend

51.2 kHz

4.7

Hold time after (repeated) start 4.0

Repeated start setup time 4.7

Stop setup time 4.0

Data hold time

Receive mode 0 ns

Transmit mode 300 ns

Data setup time 250 ns

Error signal/detect See Note 1 25 35 ms

Clock low period 4.7

Clock high period See Note 2 4.0 50

Cumulative clock low slave

extend time

Cumulative clock low master

extend time

2. T

Max. is minimum bus idle time. SMBC = SMBD=1fort>50µs will cause reset of any

HIGH

See Note 3 25 ms See Note 4 10 ms

TIMEOUT

transaction involving bq2060A that is in progress.

3. T

LOW:SEXT

is the cumulative time a slave device is allowed to extend the clock cycles in one message from initial start to the stop. The bq2060Atypically extends the clock only 20µs as a slave in the read byte or write byte protocol.

4. T

LOW:MEXT

is the cumulative time a master device is allowed to extend the clock cycles in one message from initial start to the stop. The bq2060A typically extends the clock only 20µs as a master in the read byte or write byte protocol.

µs µs

µs µ

µs µs

HDQ16 AC Specifications (VCC=2.7–3.7V, T

= -20–70 C, Unless Otherwise Noted)

OPR

Symbol Parameter Conditions Min. Typ. Max. Unit

CYCH

CYCB

STRH

STRB

DSU

DSUB

SSU

SSUB

RSPS

DH DV

Cycle time, host to bq2060A(write) 190 - -

Cycle time, bq2060Ato host (read) 190 205 250

Start hold time, host to bq2060A

(write)

5--ns

Start hold time, bq2060A to host (read) 32 - -

Data setup time - - 50 Data setup time - - 50

Data hold time 100 - Data valid time 80 - Stop setup time - - 145 Stop setup time - - 145

Response time, bq2060Ato host 190 - 320

Break time 190 - -

Break recovery time 40 - -

µs µs

µs µs µ µs µs µs µs µs µs µs

bq2060A

SMBus Timing Data

HDQ16 Break Timing

HDQ16 Host to bq2060A

STRH

DSU

HDQ16 bq2060A to Host

STRB

DSUB

SSUB

SSU

Write "1" Write "0"

CYCH

Read "1" Read "0"

CYCB

TD201803.eps

TD201805.eps

bq2060A

Ordering Information

bq2060A-E619 DBQ

Tapeand Reel

blank = tubes R = tape and reel

Package Option:

DBQ = 28-pin SSOP

Device:

bq2060ASBS v1.1-Compliant Gas Gauge IC

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TEXAS INSTRUMENTS bq2060A Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual