MAXIM DS2760 User Manual

www.maxim-ic.com

DS2760

High-Precision Li+ Battery Monitor

FEATURES

§ Li+ safety circuit

- Overvoltage protection

- Overcurrent/short circuit protection

- Undervoltage protection

§ Zero Volt Battery Recovery Charge

§ Available in two configurations:

- Internal 25mW sense resistor

- External user-selectable sense resistor

§ Current measurement

- 12-bit bidirectional measurement

- Internal sense resistor configuration:

0.625mA LSB and ±1.9A dynamic range

- External sense resistor configuration:

15.625mV LSB and ±64mV dynamic range

§ Current accumulation

- Internal sense resistor: 0.25mAhr LSB

- External sense resistor: 6.25mVhr LSB

§ Voltage measurement with 4.88mV resolution

§ Temperature measurement using integrated

sensor with 0.125°C resolution

§ System power management and control feature
support

§ 32 bytes of lockable EEPROM

§ 16 bytes of general purpose SRAM

§ Dallas 1-Wire® interface with unique 64-bit

device address

§ Low power consumption:

- Active current: 90mA max

- Sleep current: 2mA max

PIN ASSIGNMENT

CC VIN

1

SNS

SNS

SNS

1

2

PLS

2

3

2

DC

4

5

6

7

DQ

8

IS2

DS2760

16-Pin TSSOP Package

16

15

14

13

12

11

10

9

V

DD

PIO

VSS

VSS

VSS

PS

IS1

1 2 3 4

SNS

PLS DC DQ

SNS

CC IS2

Probe

VSS

VIN IS1

Probe

VDD PIO PS

VSS

DS2760

Flip-Chip Packaging

Top View

PIN DESCRIPTION

- Charge control output

CC

- Discharge control output

DC

DQ - Data input/output
PIO - Programmable I/O pin
PLS - Battery pack positive terminal input

- Power switch sense input

PS

VIN - Voltage sense input
VDD - Power supply input (2.5V to 5.5V)
VSS - Device ground
SNS - Sense resistor connection
IS1 - Current sense input
IS2 - Current sense input
SNS Probe - Do not connect
VSS Probe - Do not connect

A

B

C

D

E

F

1-Wire is a registered trademark of Dallas Semiconductor.

1 of 25 010906

DS2760

ORDERING INFORMATION

Part Marking Description

DS2760AE+ DS2760A TSSOP, External Sense Resistor, 4.275V Vov, Lead-Free
DS2760BE+ DS2760B TSSOP, External Sense Resistor, 4.35V Vov, Lead-Free
DS2760AE+T&R DS2760A DS2760AE+ on Tape & Reel, Lead-Free
DS2760 BE+T&R DS2760B DS2760BE+ on Tape & Reel, Lead-Free
DS2760AE+025 2760A25
DS2760BE+025 2760B25
DS2760AE+025/T&R 2760A25 DS2760AE+025 in Tape & Reel, Lead-Free
DS2760BE+025/T&R 2760B25 DS2760BE+025 in Tape & Reel, Lead-Free
DS2760AX DS2760A Flipchip, External Sense Resistor, Tape & Reel, 4.275V Vov
DS2760BX DS2760B Flipchip, External Sense Resistor, Tape & Reel, 4.35V Vov
DS2760AX-025 DS2760AR
DS2760BX-025 DS2760BR
DS2760AE DS2760A TSSOP, External Sense Resistor, 4.275V Vov
DS2760BE DS2760B TSSOP, External Sense Resistor, 4.35V Vov
DS2760AE/T&R DS2760A DS2760AE on Tape & Reel
DS2760 BE/T&R DS2760B DS2760BE on Tape & Reel
DS2760AE-025 2760A25
DS2760BE-025 2760B25
DS2760AE-025/T&R 2760A25 DS2760AE-025 in Tape & Reel
DS2760BE-025/T&R 2760B25 DS2760BE-025 in Tape & Reel

TSSOP, 25mW Sense Resistor, 4.275V Vov, Lead-Free
TSSOP, 25mW Sense Resistor, 4.35V Vov, Lead-Free

Flipchip, 25mW Sense Resistor, Tape & Reel, 4.275V Vov
Flipchip, 25mW Sense Resistor, Tape & Reel, 4.35V Vov

TSSOP, 25mW Sense Resistor, 4.275V Vov
TSSOP, 25mW Sense Resistor, 4.35V Vov

DESCRIPTION

The DS2760 High-Precision Li+ Battery Monitor is a data acquisition, information storage, and safety
protection device tailored for cost-sensitive battery pack applications. This low-power device integrates
precise temperature, voltage, and current measurement, nonvolatile data storage, and Li+ protection into
the small footprint of either a TSSOP package or flip chip. The DS2760 is a key component in
applications including remaining capacity estimation, safety monitoring, and battery-specific data storage.

Via its 1-Wire interface, the DS2760 gives the host system read/write access to status and control
registers, instrumentation registers, and general purpose data storage. Each device has a unique factory­programmed 64-bit net address which allows it to be individually addressed by the host system,
supporting multi-battery operation.

The DS2760 is capable of performing temperature, voltage and current measurement to a resolution
sufficient to support process monitoring applications such as battery charge control, remaining capacity
estimation, and safety monitoring. Temperature is measured using an on-chip sensor, eliminating the need
for a separate thermistor. Bidirectional current measurement and accumulation are accomplished using
either an internal 25mW sense resistor or an external device. The DS2760 also features a programmable
I/O pin that allows the host system to sense and control other electronics in the pack, including switches,
vibration motors, speakers and LEDs.

Three types of memory are provided on the DS2760 for battery information storage: EEPROM, lockable
EEPROM and SRAM. EEPROM memory saves important battery data in true nonvolatile memory that
is unaffected by severe battery depletion, accidental shorts or ESD events. Lockable EEPROM becomes
ROM when locked to provide additional security for unchanging battery data. SRAM provides
inexpensive storage for temporary data.

2

BLOCK DIAGRAM Figure 1

DQ

THERMAL

SENSE

VIN

IS1

+

IS2

PLS

PS

SNS

1-WIRE

INTERFACE

AND

ADDRESS

MUX

-

internal sense resistor configuration only

IS2 IS1

REFERENCE

25mW

VOLTAGE

ADC

REGISTERS AND

USER MEMORY

LOCKABLE EEPROM

SRAM

TEMPERATURE

VOLTAGE

CURRENT

ACCUM. CURRENT

STATUS / CONTROL

LI+ PROTECTION

chip ground

DS2760

TIMEBASE

PIO

CC

DC

VSS

3

DETAILED PIN DESCRIPTION Table 1

SYMBOL TSSOP* FLIP

CHIP*

DS2760

DESCRIPTION

CC

1 C1 Charge Protection Control Output. Controls an external p-channel

high-side charge protection FET.

DC

3 B2 Discharge Protection Control Output. Controls an external p-channel

high-side discharge protection FET.

DQ 7 B4 Data Input/Out. 1-Wire data line. Open-drain output driver. Connect

this pin to the DATA terminal of the battery pack. Pin has an internal
1mA pull-down for sensing disconnection.

PIO

14 E2 Programmable I/O Pin. Used to control and monitor user-defined

external circuitry. Open drain to VSS.

PLS 2 B1 Battery Pack Positive Terminal Input. The device monitors the state of

the battery pack’s positive terminal through this pin in order to detect
events such as the attachment of a charger or the removal of a short
circuit. Additionally, a charge path to recover a deeply depleted cell is
provided from PLS to VDD.

PS

10 E4 Power Switch Sense Input. The device wakes up from Sleep Mode

when it senses the closure of a switch to VSS on this pin. Pin has an
internal 1mA pull-up to VDD.

VIN 16 D1 Voltage Sense Input. The voltage of the Li+ cell is monitored via this

input pin. This pin has a weak pullup to VDD.

VDD 15 E1 Power Supply Input. Connect to the positive terminal of the Li+ cell

through a decoupling network.

VSS

11,12,13 F3 Device Ground. Connect directly to the negative terminal of the Li+ cell.

For the external sense resistor configuration, connect the sense resistor
between VSS and SNS.

SNS 4,5,6 A3 Sense Resistor Connection. Connect to the negative terminal of the

battery pack. In the internal sense resistor configuration, the sense resistor
is connected between VSS and SNS.

IS1 9 D4 Current Sense Input. This pin is internally connected to VSS through a

4.7kW resistor. Connect a 0.1mF capacitor between IS1 and IS2 to
complete a low-pass input filter.

IS2 8 C4 Current Sense Input. This pin is internally connected to SNS through a

4.7kW resistor.

SNS

N/A C2

Do Not Connect.

Probe

VSS

N/A D2

Do Not Connect.

Probe

* Mechanical drawing for the 16-pin TSSOP and DS2760 flip-chip package can be found at:

http://pdfserv.maxim-ic.com/arpdf/Packages/16tssop.pdf
http://pdfserv.maxim-ic.com/arpdf/Packages/chips/2760x.pdf

4

APPLICATION EXAMPLE Figure 2

(2)

A

0

(1)

102

PACK+

1k

W

1k

150W

1

150W

2

DAT

PACK-

1 – R
2 – R

is present for external sense resistor configurations only

SENS

SENSINT

is present for internal sense resistor configurations only

W

DS2760

CC
PLS
DC
SNS
SNS
SNS
DQ
IS2

VIN

V

DD

PIO
VSS
VSS
VSS

PS

IS1

104

R

W

KS

150

104

4.7kW

4.7kW

DS2760

R

SENSINT

voltage

sense

W

1k

SENS

SNS

R

IS2 IS1

DS2760

BAT+

PS

BAT-

VSS

R

KS

4.7kW

5

DS2760

POWER MODES

The DS2760 has two power modes: Active and Sleep. While in Active Mode, the DS2760 continually
measures current, voltage and temperature to provide data to the host system and to support current
accumulation and Li+ safety monitoring. In Sleep Mode, the DS2760 ceases these activities. The
DS2760 enters Sleep Mode when any of the following conditions occurs:

§ the PMOD bit in the Status Register has been set to 1 and the DQ line is low for longer than
2 seconds (pack disconnection)

§ the voltage on VIN drops below undervoltage threshold VUV for t

(cell depletion)

UVD

§ the pack is disabled through the issuance of a SWAP command (SWEN bit =1)

The DS2760 returns to Active Mode when any of the following occurs:

§ the PMOD bit has been set to 1 and the SWEN bit is set to 0 and the DQ line is pulled high
(pack connection)

§ the PS pin is pulled low (power switch)

§ the voltage on PLS becomes greater than the voltage on VIN (charger connection) with the SWEN bit

set to 0

§ the pack is enabled through the issuance of a SWAP command (SWEN bit =1)

The DS2760 defaults to Sleep Mode when power is first applied.

LI+ PROTECTION CIRCUITRY

During Active Mode, the DS2760 constantly monitors cell voltage and current to protect the battery from
overcharge (overvoltage), overdischarge (undervoltage) and excessive charge and discharge currents
(overcurrent, short circuit). Conditions and DS2760 responses are described in the sections below and
summarized in Table 2 and Figure 3.

LI+ PROTECTION CONDITIONS AND DS2760 RESPONSES Table 2

Activation Condition

Name

Overvoltage VIN > V
Undervoltage VIN < V

Threshold Delay Response

OV

UV

t

OVD CC

t

UVD CC

high

, DC high,

Sleep Mode

Overcurrent, Charge V
Overcurrent, Discharge V
Short Circuit V

VIS = V

IS1

– V

. Logic high = V

IS2

IS

IS

SNS

< -V

PLS

(2)

> V

> V

OC

OC

(2)

SC

t

OCD CC

t

OCD DC

t

SCD DC

for CC and VDD for

, DC high

high
high

All voltages are with respect to VSS. I

DC

.

references current delivered from pin SNS.

(1) If V

charges the battery and allows V

<2.2V, release is delayed until the recovery charge current (IRC) passed from PLS to VDD

DD

to exceed 2.2V.

DD

(2) for the internal sense resistor configuration, the overcurrent thresholds are expressed in terms of

current: I
(3) with test current I
(4) with test current I

> IOC for charge direction and I

SNS

current flowing from PLS to VSS (pull-down on PLS)

TST

current flowing from VDD to PLS (pull-up on PLS)

TST

< -IOC for discharge direction

SNS

Overvoltage. If the voltage of the cell exceeds overvoltage threshold V
overvoltage delay t

, the DS2760 shuts off the external charge FET and sets the OV flag in the

OVD

Protection Register. When the cell voltage falls below charge enable threshold V

for a period longer than

OV

CE

Release

Threshold

VIN < V

V

PLS

> V

DD

CE

(1)

(charger connected)

V

PLS

V

> VDD – V

PLS

> VDD – V

V

PLS

< VDD – V

TP

TP

TP

(3)

(4)

(4)

SNS

, the DS2760 turns the

6

DS2760

charge FET back on (unless another protection condition prevents it). Discharging remains enabled
during overvoltage.

Undervoltage. If the voltage of the cell drops below undervoltage threshold VUV for a period longer than
undervoltage delay t
Protection Register, and enters Sleep Mode. The DS2760 provides a current-limited (I

, the DS2760 shuts off the charge and discharge FETs, sets the UV flag in the

UVD

) recovery

RC

charge path from PLS to VDD to gently charge severely depleted cells. The recovery path is enabled
when 0 £ VDD < 3V(typ). Once VDD reaches 3V(typ), the DS2760 will return to normal operation,
awaiting connection of a charger to turn on the charge FET and pull out of Sleep Mode.

Overcurrent, Charge Direction. The voltage difference between the IS1 pin and the IS2 pin (V
– V

) is the filtered voltage drop across the current sense resistor. If VIS exceeds overcurrent threshold

IS2

for a period longer than overcurrent delay t

V

OC

, the DS2760 shuts off both external FETs and sets the

OCD

IS

= V

IS1

COC flag in the Protection Register. The charge current path is not re-established until the voltage on the
PLS pin drops below V

– VTP. The DS2760 provides a test current of value I

DD

from PLS to VSS to

TST

pull PLS down in order to detect the removal of the offending charge current source.

Overcurrent, Discharge Direction. If VIS is less than –VOC for a period longer than t

, the DS2760

OCD

shuts off the external discharge FET and sets the DOC flag in the Protection Register. The discharge
current path is not re-established until the voltage on PLS rises above VDD – VTP. The DS2760 provides a
test current of value I

from VDD to PLS to pull PLS up in order to detect the removal of the offending

TST

low-impedance load.

Short Circuit. If the voltage on the SNS pin with respect to VSS exceeds short circuit threshold VSC for
a period longer than short circuit delay t

, the DS2760 shuts off the external discharge FET and sets the

SCD

DOC flag in the Protection Register. The discharge current path is not re-established until the voltage on
PLS rises above VDD – VTP. The DS2760 provides a test current of value I

from VDD to PLS to pull

TST

PLS up in order to detect the removal of the short circuit.

LITHIUM-ION PROTECTION CIRCUITRY EXAMPLE WAVEFORMS Figure 3

V

7

CELL

charge

V

IS

discharge

(1)

CC

DC

t

OVD

t

OVD

t

t

t

OCD

t

Sleep
Mode

(1) To allow the device to react quickly to short circuits, detection is actually done on the SNS pin rather

than on the filtered IS1 and IS2 pins. The actual short circuit detect condition is V

> VSC.

SNS

V

OV

V

CE

V

UV

V

OC

0

-V

OC

-V

SC

V

PLS

VSS

VDD

VSS

active

inactive

DS2760

Summary. All of the protection conditions described above are OR’ed together to affect the CC and DC
outputs.

= (Undervoltage) or (Overcurrent, EITHER Direction) or (Short Circuit) or

DC

(Protection Register bit DE = 0) or (Sleep Mode)

= (Overvoltage) or (Undervoltage) or (Overcurrent, Charge Direction) or (Protection Register

CC

bit CE = 0) or (Sleep Mode)

CURRENT MEASUREMENT

In the Active Mode of operation, the DS2760 continually measures the current flow into and out of the
battery by measuring the voltage drop across a current sense resistor. The DS2760 is available in two
configurations: (1) internal 25mW current sense resistor, and (2) external user-selectable sense resistor. In
either configuration, the DS2760 considers the voltage difference between pins IS1 and IS2 (VIS = V
V

) to be the filtered voltage drop across the sense resistor. A positive VIS value indicates current is

IS2

IS1

–

flowing into the battery (charging), while a negative VIS value indicates current is flowing out of the
battery (discharging).

VIS is measured with a signed resolution of 12-bits. The current register is updated in two’s complement
format every 88ms (128/fsample) with an average of 128 readings. Currents outside the range of the
register are reported at the limit of the range. The format of the Current Register is shown in Figure 4.

For the internal sense resistor configuration, the DS2760 maintains the Current Register in units of Amps,
with a resolution of 0.625mA and full scale range of no less than ±1.9A (see Note 7 on IFS spec for more

details). The DS2760 automatically compensates for internal sense resistor process variations and
temperature effects when reporting current.

For the external sense resistor configuration, the DS2760 writes the measured VIS voltage to the Current
Register, with a resolution of 15.625mV and a full scale range of ±64mV.

CURRENT REGISTER FORMAT Figure 4

MSB—Address 0E LSb—Address 0F

11

S 2

210 29 28 27 26 25 24 23 22 21 20 X X X

MSb LSb MSb LSb

Units: 0.625 mA for internal sense resistor

15.625 mV for external sense resistor

CURRENT ACCUMULATOR

The Current Accumulator facilitates remaining capacity estimation by tracking the net current flow into
and out of the battery. Current flow into the battery increments the Current Accumulator while current
flow out of the battery decrements it. Data is maintained in the Current Accumulator in two’s­complement format. The format of the Current Accumulator is shown in Figure 5.

When the internal sense resistor is used, the DS2760 maintains the Current Accumulator in units of Amp­hours, with a resolution of 0.25mAhrs and full scale range of ±8.2Ahrs. When using an external sense

8

DS2760

resistor, the DS2760 maintains the Current Accumulator in units of Volt-hours, with a resolution of

6.25 mVhrs and a full scale range of ±205 mVhrs.

The Current Accumulator is a read/write register that can be altered by the host system as needed.

CURRENT ACCUMULATOR FORMAT Figure 5

MSB—Address 10 LSb—Address 11

14

S 2

213 212 211 210 29 28 27 26 25 24 23 22 21 20

MSb LSb MSb LSb

Units: 0.25 mAhrs for internal sense resistor

6.25 mVhrs for external sense resistor

CURRENT OFFSET COMPENSATION

Current measurement and the current accumulation are both internally compensated for offset on a
continual basis minimizing error resulting from variations in device temperature and voltage.
Additionally a constant bias may be utilized to alter any other sources of offset. This bias resides in
EEPROM address 33h in two’s-complement format and is subtracted from each current measurement.
The current offset bias is applied to both the internal and external sense resistor configurations. The
factory default for the current offset compensation is a value of 0.

CURRENT OFFSET BIAS Figure 6

Address 33

S 26 25 24 23 22 21 20

MSb LSb

Units: 0.625 mA for internal sense resistor

15.625 mV for external sense resistor

VOLTAGE MEASUREMENT

The DS2760 continually measures the voltage between pins VIN and VSS over a range of 0 to 4.75V.
The resulting data is placed in the Voltage Register in two’s-complement format with a resolution of

4.88mV. Voltages above the maximum register value are reported as the maximum value. The Voltage
Register format is shown in Figure 7.

VOLTAGE REGISTER FORMAT Figure 7

MSB—Address 0C LSb—Address 0D

S 29 28 27 26 25 24 23 22 21 20 X X X X X

MSb LSb MSb LSb

Units: 4.88 mV

9

DS2760

TEMPERATURE MEASUREMENT

The DS2760 uses an integrated temperature sensor to continually measure battery temperature.
Temperature measurements are placed in the Temperature Register in two’s-complement format with a
resolution of 0.125°C over a range of ±127°C. The Temperature Register format is shown in Figure 8.

TEMPERATURE REGISTER FORMAT Figure 8

MSB—Address 18 LSB—Address 19

9

S 2

28 27 26 25 24 23 22 21 20 X X X X X

MSb LSb MSb LSb

Units: 0.125°C

PROGRAMMABLE I/O

To use the PIO pin as an output, write the desired output value to the PIO bit in the Special Feature
Register. Writing a 0 to the PIO bit enables the PIO output driver, pulling the PIO pin to VSS. Writing a
1 to the PIO bit disables the output driver, allowing the PIO pin to be pulled high or used as an input. To
sense the value on the PIO pin, read the PIO bit. The DS2760 turns off the PIO output driver and sets the
PIO high when it enters Sleep Mode or when DQ is low for more than 2 seconds, regardless of the state
of the PMOD bit.

POWER SWITCH INPUT

The DS2760 provides a power control function that uses the discharge protection FET to gate battery
power to the system. The PS pin, internally pulled to VDD through a 1mA current source, is continuously

monitored for a low-impedance connection to VSS. If the DS2760 is in Sleep Mode, the detection of a
low on PS causes the device to transition into Active Mode, turning on the discharge FET. If the DS2760
is already in Active Mode, activity on PS has no effect other than the mirroring of its logic level in the

bit in the Special Feature Register. The reading of a 0 in the PS bit should be immediately followed

PS

by writing a 1 to the PS bit to ensure proper operation.

MEMORY

The DS2760 has a 256-byte linear address space with registers for instrumentation, status and control in
the lower 32 bytes, with lockable EEPROM and SRAM memory occupying portions of the remaining
address space. All EEPROM and SRAM memory is general-purpose except addresses 30h, 31h, and 33h,
which should be written with the default values for the Protection Register, Status Register, and Current
Offset Register, respectively. When the MSB of any 2-byte register is read, both the MSB and LSB are
latched and held for the duration of the Read Data command to prevent updates during the read and
ensure synchronization between the two register bytes. For consistent results, always read the MSB and
the LSB of a two-byte register during the same Read Data command sequence.

EEPROM memory is shadowed by RAM to eliminate programming delays between writes and to allow
the data to be verified by the host system before being copied to EEPROM. All reads and writes to/from
EEPROM memory actually access the shadow RAM. In unlocked EEPROM blocks, the Write Data
command updates shadow RAM. In locked EEPROM blocks, the Write Data command is ignored. The
Copy Data command copies the contents of shadow RAM to EEPROM in an unlocked block of
EEPROM but has no effect on locked blocks. The Recall Data command copies the contents of a block of
EEPROM to shadow RAM regardless of whether the block is locked or not.

10

DS2760

b

b

b

b

b

b

b

b

MEMORY MAP Table 3

Address (Hex)

00 Protection Register R/W
01 Status Register R

02-06 Reserved

07 EEPROM Register R/W
08 Special Feature Register R/W

09-0B Reserved

0C Voltage Register MSb R
0D Voltage Register LSb R

0E Current Register MSB R
0F Current Register LSb R
10 Accumulated Current Register MSB R/W
11 Accumulated Current Register LSb R/W

12-17 Reserved

18 Temperature Register MSB R
19 Temperature Register LSb R

1A-1F Reserved

20-2F EEPROM, block 0 R/W*
30-3F EEPROM, block 1 R/W*
40-7F Reserved
80-8F SRAM R/W
90-FF Reserved

* Each EEPROM block is read/write until locked by the LOCK command, after which it is read-only.

Description

Read/Write

PROTECTION REGISTER

The Protection Register consists of flags that indicate protection circuit status and switches that give
conditional control over the charging and discharging paths. Bits OV, UV, COC and DOC are set when
corresponding protection conditions occur and remain set until cleared by the host system. The default
values of the CE and DE bits of the Protection Register are stored in lockable EEPROM in the
corresponding bits in address 30h. A Recall Data command for EEPROM block 1 recalls the default
values of 1 into CE and DE. The format of the Protection Register is shown in Figure 9. The function of
each bit is described in detail in the following paragraphs.

PROTECTION REGISTER FORMAT Figure 9

Address 00

it 7

OV UV COC DOC

OV – Overvoltage Flag. When set to 1, this bit indicates the battery pack has experienced an overvoltage
condition. This bit must be reset by the host system.

UV – Undervoltage Flag. When set to 1, this bit indicates the battery pack has experienced an
undervoltage condition. This bit must be reset by the host system.

11

it 6

it 5

it 4

it 3

CC

it 2

DC

it 1

CE DE

it 0

DS2760

b

b

b

b

b

b

b

b

COC – Charge Overcurrent Flag. When set to 1, this bit indicates the battery pack has experienced a
charge-direction overcurrent condition. This bit must be reset by the host system.

DOC – Discharge Overcurrent Flag. When set to 1, this bit indicates the battery pack has experienced a
discharge-direction overcurrent condition. This bit must be reset by the host system.

CC – CC Pin Mirror. This read-only bit mirrors the state of the CC output pin.

DC – DC Pin Mirror. This read-only bit mirrors the state of the DC output pin.

CE – Charge Enable. Writing a 0 to this bit disables charging (

CC output high, external charge FET off)

regardless of cell or pack conditions. Writing a 1 to this bit enables charging, subject to override by the
presence of any protection conditions. The DS2760 automatically sets this bit to 1 when it transitions
from Sleep Mode to Active Mode.

DE – Discharge Enable. Writing a 0 to this bit disables discharging (

DC output high, external discharge
FET off) regardless of cell or pack conditions. Writing a 1 to this bit enables discharging, subject to
override by the presence of any protection conditions. The DS2760 automatically sets this bit to 1 when
it transitions from Sleep Mode to Active Mode.

STATUS REGISTER

The default values for the Status Register bits are stored in lockable EEPROM in the corresponding bits
of address 31h. A Recall Data command for EEPROM block 1 recalls the default values into the Status
Register bits. The format of the Status Register is shown in Figure 10. The function of each bit is
described in detail in the following paragraphs.

STATUS REGISTER FORMAT Figure 10

Address 01

it 7

it 6

it 5

it 4

it 3

it 2

it 1

it 0

X X PMOD RNAOP SWEN X X X

PMOD – Sleep Mode Enable. A value of 1 in this bit enables the DS2760 to enter Sleep Mode when the
DQ line goes low for greater than 2 seconds and leave Sleep Mode when the DQ line goes high. A value
of 0 disables DQ-related transitions into and out of Sleep Mode. This bit is read-only. The desired
default value should be set in bit 5 of address 31h. The factory default is 0.

RNAOP – Read Net Address Opcode. A value of 0 in this bit sets the opcode for the Read Net Address
command to 33h, while a 1 sets the opcode to 39h. This bit is read-only. The desired default value should
be set in bit 4 of address 31h. The factory default is 0.

SWEN - SWAP Command Enable. A value of 1 in this bit location enables the recognition of a SWAP
command. If set to 0, SWAP commands are ignored. The desired default value should be set in bit 3 of
address 31h. This bit is read-only. The factory default is 0.

X – Reserved bits.

12

DS2760

b

b

b

b

b

b

b

b

b

b

b

b

b

b

b

b

EEPROM REGISTER

The format of the EEPROM Register is shown in Figure 11. The function of each bit is described in
detail in the following paragraphs.

EEPROM REGISTER FORMAT Figure 11

Address 07

it 7

it 6

it 5

it 4

it 3

it 2

it 1

it 0

EEC LOCK X X X X BL1 BL0

EEC – EEPROM Copy Flag. A 1 in this read-only bit indicates that a Copy Data command is in
progress. While this bit is high, writes to EEPROM addresses are ignored. A 0 in this bit indicates that
data may be written to unlocked EEPROM blocks.

LOCK – EEPROM Lock Enable. When this bit is 0, the Lock command is ignored. Writing a 1 to this
bit enables the Lock command. After the Lock command is executed, the LOCK bit is reset to 0. The
factory default is 0.

BL1 – EEPROM Block 1 Lock Flag. A 1 in this read-only bit indicates that EEPROM Block 1
(addresses 30-3F) is locked (read-only) while a 0 indicates Block 1 is unlocked (read/write).

BL0 – EEPROM Block 0 Lock Flag. A 1 in this read-only bit indicates that EEPROM Block 0
(addresses 20-2F) is locked (read-only) while a 0 indicates Block 0 is unlocked (read/write).

X – Reserved bits.

SPECIAL FEATURE REGISTER

The format of the Special Feature Register is shown in Figure 12. The function of each bit is described in
detail in the following paragraphs.

SPECIAL FEATURE REGISTER FORMAT Figure 12

Address 08

it 7

PS

it 6

it 5

it 4

it 3

it 2

it 1

it 0

PIO MSTR X X X X X

PS – PS Pin Mirror. This read-only bit mirrors the state of the PS pin. The reading of a 0 in this bit

should be immediately followed by writing a 1 to this location to insure proper operation.

PIO – PIO Pin Sense and Control. See the Programmable I/O section for details on this read/write bit.

MSTR - SWAP Master Status Bit. This bit indicates whether a device has been selected through the

SWAP command. Selection of this device through the SWAP command and the appropriate Net Address
will result in setting this bit, indicating that this device is the master. A 0 signifies that this device is not
the master.

X – Reserved bits.

13

DS2760

1-WIRE BUS SYSTEM

The 1-Wire bus is a system which has a single bus master and one or more slaves. A multidrop bus is a
1-Wire bus with multiple slaves. A single-drop bus has only one slave device. In all instances, the
DS2760 is a slave device. The bus master is typically a microprocessor in the host system. The
discussion of this bus system consists of four topics: 64-Bit Net Address, Hardware Configuration,
Transaction Sequence, and 1-Wire Signaling.

64-BIT NET ADDRESS

Each DS2760 has a unique, factory-programmed 1-Wire net address which is 64 bits in length. The first
8 bits are the 1-Wire family code (30h for DS2760). The next 48 bits are a unique serial number. The
last 8 bits are a CRC of the first 56 bits (see Figure 13). The 64-bit net address and the 1-Wire I/O
circuitry built into the device enable the DS2760 to communicate via the 1-Wire protocol detailed in the

1-Wire Bus System section of this data sheet.

1-WIRE NET ADDRESS FORMAT Figure 13

8-bit CRC 48-bit Serial Number 8-Bit Family Code 30h)
MSb LSb

CRC GENERATION

The DS2760 has an 8-bit CRC stored in the most significant byte of its 1-Wire net address. To ensure
error-free transmission of the address, the host system can compute a CRC value from the first 56 bits of
the address and compare it to the CRC from the DS2760. The host system is responsible for verifying the
CRC value and taking action as a result. The DS2760 does not compare CRC values and does not
prevent a command sequence from proceeding as a result of a CRC mismatch. Proper use of the CRC
can result in a communication channel with a very high level of integrity.

The CRC can be generated by the host using a circuit consisting of a shift register and XOR gates as
shown in Figure 10, or it can be generated in software. Additional information about the Dallas 1-Wire
Cyclic Redundancy Check is available in Application Note 27 entitled “

Redundancy Checks with Dallas Semiconductor Touch Memory Products”. (This application note can be

found on the Maxim/Dallas Semiconductor website at www.maxim-ic.com).

In the circuit in Figure 14, the shift register bits are initialized to 0. Then, starting with the least
significant bit of the family code, one bit at a time is shifted in. After the 8
been entered, then the serial number is entered. After the 48

th

bit of the serial number has been entered,

the shift register contains the CRC value.

Understanding and Using Cyclic

th

bit of the family code has

14

DS2760

1-WIRE CRC GENERATION BLOCK DIAGRAM Figure 14

MSb

XOR

XOR

LSb

input

XOR

HARDWARE CONFIGURATION

Because the 1-Wire bus has only a single line, it is important that each device on the bus be able to drive
it at the appropriate time. To facilitate this, each device attached to the 1-Wire bus must connect to the
bus with open-drain or tri-state output drivers. The DS2760 used an open-drain output driver as part of
the bidirectional interface circuitry shown in Figure 15. If a bidirectional pin is not available on the bus
master, separate output and input pins can be tied together.

The 1-Wire bus must have a pull-up resistor at the bus-master end of the bus. For short line lengths, the
value of this resistor should be approximately 5k

W. The idle state for the 1-Wire bus is high. If, for any

reason, a bus transaction must be suspended, the bus MUST be left in the idle state in order to properly
resume the transaction later. If the bus is left low for more than 120

ms, slave devices on the bus begin to

interpret the low period as a Reset Pulse, effectively terminating the transaction.

1-WIRE BUS INTERFACE CIRCUITRY Figure 15

BUS MASTER DS2760 1-WIRE PORT

+V

(2.0V–5.5V)

PULLUP

4.7kW

Rx Rx

Tx

Rx = Receive
Tx = Transmit

1mA
Typ.

W

100
MOSFET

Tx

TRANSACTION SEQUENCE

The protocol for accessing the DS2760 via the 1-Wire port is as follows:

§ Initialization

§ Net Address Command

§ Function Command

§ Transaction/Data

The sections that follow describe each of these steps in detail.

15

DS2760

All transactions of the 1-Wire bus begin with an initialization sequence consisting of a Reset Pulse
transmitted by the bus master followed by a presence pulse simultaneously transmitted by the DS2760
and any other slaves on the bus. The presence pulse tells the bus master that one or more devices are on
the bus and ready to operate. For more details, see the

1-Wire Signaling section.

NET ADDRESS COMMANDS

Once the bus master has detected the presence of one or more slaves, it can issue one of the Net Address
Commands described in the following paragraphs. The name of each ROM Command is followed by the
8-bit opcode for that command in square brackets. Figure 16 presents a transaction flowchart of the Net
Address Commands.

Read Net Address [33h or 39h]. This command allows the bus master to read the DS2760’s 1-Wire net
address. This command can only be used if there is a single slave on the bus. If more than one slave is
present, a data collision occurs when all slaves try to transmit at the same time (open-drain produces a
wired-AND result). The RNAOP bit in the Status Register selects the opcode for this command, with
RNAOP=0 indicating 33h and RNAOP=1 indicating 39h.

Match Net Address [55h]. This command allows the bus master to specifically address one DS2760 on
the 1-Wire bus. Only the addressed DS2760 responds to any subsequent Function Command. All other
slave devices ignore the Function Command and wait for a reset pulse. This command can be used with
one or more slave devices on the bus.

Skip Net Address [CCh]. This command saves time when there is only one DS2760 on the bus by
allowing the bus master to issue a Function Command without specifying the address of the slave. If
more than one slave device is present on the bus, a subsequent Function Command can cause a data
collision when all slaves transmit data at the same time.

Search Net Address [F0h]. This command allows the bus master to use a process of elimination to
identify the 1-Wire net addresses of all slave devices on the bus. The search process involves the
repetition of a simple three-step routine: read a bit, read the complement of the bit, then write the desired
value of that bit. The bus master performs this simple three-step routine on each bit location of the net
address. After one complete pass through all 64 bits, the bus master knows the address of one device.
The remaining devices can then be identified on additional iterations of the process. See Chapter 5 of the

Book of DS19xx iButton® Standards for a comprehensive discussion of a net address search, including an

actual example. (This publication can be found on the Maxim/Dallas Semiconductor website at
www.maxim-ic.com).

SWAP [AAh]. SWAP is a Net Address level command specifically intended to aid in distributed
multiplexing applications and is described specifically with regards to power control using the 27xx series
of products. The term power control refers to the ability of the DS2760 to control the flow of power into

or out the battery pack using control pins

DC and CC . The SWAP command is issued followed by the
Net Address. The effect is to cause the addressed device to enable power to or from the system while
simultaneously (break-before-make) deselecting and powering down (SLEEP) all other packs. This
switching sequence is controlled by a timing pulse issued on the DQ line following the net address. The
falling edge of the pulse is used to disable power with the rising edge enabling power flow by the selected
device. The DS2760 will recognize a SWAP command, device address, and timing pulse if and only if
the SWEN bit is set.

iButton is a registered trademark of Dallas Semiconductor.

16

DS2760

FUNCTION COMMANDS

After successfully completing one of the Net Address Commands, the bus master can access the features
of the DS2760 with any of the Function Commands described in the following paragraphs. The name of
each function is followed by the 8-bit opcode for that command in square brackets.

Read Data [69h, XX]. This command reads data from the DS2760 starting at memory address XX. The
LSb of the data in address XX is available to be read immediately after the MSb of the address has been
entered. Because the address is automatically incremented after the MSb of each byte is received, the
LSb of the data at address XX+1 is available to be read immediately after the MSb of the data at address
XX. If the bus master continues to read beyond address FFh, the DS2760 outputs logic 1 until a Reset
Pulse occurs. Addresses labeled “Reserved” in the Memory Map contain undefined data. The Read Data
command may be terminated by the bus master with a Reset Pulse at any bit boundary.

Write Data [6 Ch, XX]. This command writes data to the DS2760 starting at memory address XX. The
LSb of the data to be stored at address XX can be written immediately after the MSb of address has been
entered. Because the address is automatically incremented after the MSb of each byte is written, the LSb
to be stored at address XX+1 can be written immediately after the MSb to be stored at address XX. If the
bus master continues to write beyond address FFh, the DS2760 ignores the data. Writes to read-only
addresses, reserved addresses and locked EEPROM blocks are ignored. Incomplete bytes are not written.
Writes to unlocked EEPROM blocks are to shadow RAM rather than EEPROM. See the
for more details.

Copy Data [48h, XX]. This command copies the contents of shadow RAM to EEPROM for the 16-byte
EEPROM block containing address XX. Copy Data commands that address locked blocks are ignored.
While the Copy Data command is executing, the EEC bit in the EEPROM Register is set to 1 and writes
to EEPROM addresses are ignored. Reads and writes to non-EEPROM addresses can still occur while
the copy is in progress. The Copy Data command takes t

time to execute, starting on the next falling

EEC

edge after the address is transmitted.

Recall Data [B8h, XX]. This command recalls the contents of the 16-byte EEPROM block containing
address XX to shadow RAM.

Lock [6 Ah, XX]. This command locks (write-protects) the 16-byte block of EEPROM memory
containing memory address XX. The LOCK bit in the EEPROM Register must be set to l before the
Lock command is executed. If the LOCK bit is 0, the Lock command has no effect. The Lock command
is permanent; a locked block can never be written again.

Memory section

17

FUNCTION COMMANDS Table 4

Command

Read Data

Description

Reads data from memory

starting at address XX

Write Data Writes data to memory

starting at address XX

Copy Data Copies shadow RAM data

to EEPROM block

containing address XX

Recall Data Recalls EEPROM block

containing address XX to

shadow RAM

Lock

Permanently locks the

block of EEPROM

containing address XX

Command

Protocol

69h, XX

Bus State After

Command Protocol

Master Rx

Bus Data

up to 256 bytes

of data

6Ch, XX Master Tx up to 256 bytes

of data

48h, XX

Bus Idle

B8h, XX

Bus Idle

6Ah, XX

Bus Idle

none

none

none

DS2760

18

NET ADDRESS COMMAND FLOW CHART Figure 16

33h / 39h

READ

DS2760 Tx

FAMILY CODE

1 BYTE

DS2760 Tx

SERIAL NUMBER

6 BYTES

DS2760 Tx

CRC

1 BYTE

MASTER Tx

FUNCTION

COMMAND

NO NO NO

YES

MATCH

MASTER Tx

BIT 0

BIT 0

MATCH ?

MASTER Tx

BIT 1

BIT 1

MATCH ?

MASTER Tx

BIT 63

BIT 63

MATCH ?

NO

MASTER Tx

RESET PULSE

DS2760 Tx

PRESENCE PULSE

MASTER Tx

NET ADDRESS

COMMAND

55h

NO NO

NO NO

F0h

SEARCH

YESYES YES

DS2760 Tx BIT 0

DS2760 Tx BIT 0

MASTER Tx BIT 0

BIT 0

MATCH ?

DS2760 Tx BIT 1

DS2760 Tx BIT 1

MASTER Tx BIT 1

MATCH ?

DS2760 Tx BIT 63

DS2760 Tx BIT 63

MASTER Tx BIT 63

YESYES

BIT 1

YESYES

NO

NO

NO

FALLING EDGE

DS2760 to Sleep

OF DQ

Mode

SWAP

MASTER Tx

BIT 0

MATCH ?

MASTER Tx

BIT 1

MATCH ?

MASTER Tx

BIT 63

BIT 63

MATCH ?

AAh

YES

BIT 0

YES

BIT 1

NO

YES

RISING EDGE

DS2760 to Active

YES

OF DQ

Mode

MASTER Tx

FUNCTION

COMMAND

CCh

SKIP

DS2760

NO

YES

19

DS2760

I/O SIGNALING

The 1-Wire bus requires strict signaling protocols to insure data integrity. The four protocols used by the
DS2760 are: the initialization sequence (Reset Pulse followed by Presence Pulse), Write 0, Write 1, and
Read Data. All of these types of signaling except the Presence Pulse are initiated by the bus master.

The initialization sequence required to begin any communication with the DS2760 is shown in Figure 17.
A Presence Pulse following a Reset Pulse indicates the DS2760 is read to accept a Net Address
Command. The bus master transmits (Tx) a Reset Pulse for t

. The bus master then releases the line

RSTL

and goes into receive mode (Rx). The 1-Wire bus line is then pulled high by the pull-up resistor. After
detecting the rising edge on the DQ pin, the DS2760 waits for t
for t

PDL

.

and then transmits the Presence Pulse

PDH

1-WIRE INITIALIZATION SEQUENCE Figure 17

DQ

LINE TYPE LEGEND:

t

RSTL

t

PDH

t

PDL

t

RSTH

PACK+

PACK–

Both bus master and
DS2760 active low

WRITE TIME SLOTS

A write time slot is initiated when the bus master pulls the 1-Wire bus from a logic high (inactive) level to
a logic low level. There are two types of write time slots: Write 1 and Write 0. All write time slots must
be t

(60ms to 120ms) in duration with a 1ms minimum recovery time, t

SLOT

DS2760 samples the 1-Wire bus line between 15

ms and 60ms after the line falls. If the line is high when

, between cycles. The

REC

sampled, a Write 1 occurs. If the line is low when sampled, a Write 0 occurs (see Figure 18). For the bus
master to generate a Write 1 time slot, the bus line must be pulled low and then released, allowing the line
to be pulled high within 15

ms after the start of the write time slot. For the host to generate a Write 0 time

slot, the bus line must be pulled low and held low for the duration of the write time slot.

READ TIME SLOTS

A read time slot is initiated when the bus master pulls the 1-Wire bus line from a logic high level to a
logic low level. The bus master must keep the bus line low for at least 1
DS2760 to present valid data. The bus master can then sample the data t
read time slot. By the end of the read time slot, the DS2760 releases the bus line and allows it to be
pulled high by the external pull-up resistor. All read time slots must be t
with a 1

ms minimum recovery time, t

, between cycles. See Figure 18 for more information.

REC

ms and then release it to allow the

(15ms) from the start of the

RDV

(60ms to 120ms) in duration

SLOT

20

1-WIRE WRITE AND READ TIME SLOTS Figure 18

SLO

SLO

C

SLO

WRITE 0 SLOT WRITE 1 SLOT

t

T

t

t

RE

t

DQ

15ms

DS2760 Sample Window

15ms

30ms

>1ms

READ 0 SLOT READ 1 SLOT

t

T

t

DQ

t

>1ms

t

LINE TYPE LEGEND:

Both bus master and
DS2760 active low

SWAP COMMAND TIMING Figure 19

DQ

t

SWOFF

CC , DC

CC , DC

t

SWL

t

T

DS2760 Sample Window

15ms15ms 30ms

t

t

SWON

DS2760

PACK+

PACK–

PACK+

PACK–

21

DS2760

ABSOLUTE MAXIMUM RATINGS*

Voltage on PLS and CC pin, Relative to VSS -0.3V to +18V
Voltage on PIO pin, Relative to VSS -0.3V to +12V

Voltage on VIN and

PS , Relative to VSS -0.3V to V

+ 0.3

DD

Voltage on any other pin, Relative to VSS -0.3V to +6V
Continuous Internal Sense Resistor Current
Pulsed Internal Sense Resistor Current

±2.5A
±50A for <100µs/sec, <1000 pulses

Operating Temperature Range -40°C to +85°C
Storage Temperature Range -55°C to +125°C
Soldering Temperature See IPC/JEDEC J-STD-020A

Specification

* This is a stress rating only and functional operation of the device at these or any other conditions above

those indicated in the operation sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods of time may affect reliability.

RECOMMENDED DC
OPERATING CONDITIONS (-20°C to +70°C, 2.5V £ V

£ 5.5V)

DD

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Supply Voltage

V

DD

2.5 5.5 V 1

Data Pin DQ -0.3 5.5 V 1

DC ELECTRICAL CHARACTERISTICS (-20°C to +70°C; 2.5V £ VDD £ 5.5V)

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Active Current I

ACTIVE

DQ =

V

DD

,

60 90

mA

norm. operation

Sleep Mode Current I

DQ = 0V,

SLEEP

1 2

mA

no activity,

floating

PS

Input Logic High:

VIH 1.5 V 1

DQ, PIO
Input Logic High: PS

Input Logic Low:

V

IH

VIL 0.4 V 1

- 0.2V V 1

DD

V

DQ, PIO
Input Logic Low: PS

Output Logic High: CC

Output Logic High: DC
Output Logic Low:

V

IL

V

OH

V

OH

V

OL

I

= -0.1mA V

OH

I

= -0.1mA VDD - 0.4V

OH

I

= 0.1mA 0.4 V 1

OL

PLS

- 0.4V

V 1

V 1

0.2 V 1

CC , DC

Output Logic Low:
DQ, PIO
DQ Pulldown Current IPD 1

Input Resistance: VIN
Internal Current Sense

Resistor
DQ Low to Sleep time t

V

OL

R

IN

R

SNS

SLEEP

I

= 4mA 0.4 V 1

OL

5

+25°C

20 25 30

mA

MW

mW

2.1 sec

22

ELECTRICAL CHARACTERISTICS:

DS2760

PROTECTION CIRCUITRY (0°C to +50°C; 2.5V £ V

£ 5.5V)

DD

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Overvoltage Detect VOV 4.325

4.250

4.350

4.275

4.375

4.300

V 1, 2

Charge Enable VCE 4.10 4.15 4.20 V 1
Undervoltage Detect VUV 2.5 2.6 2.7 V 1
Overcurrent Detect I

OC

1.8 1.9 2.0 A 3
Overcurrent Detect VOC 45 47.5 50 mV 1, 4
Short Circuit Detect ISC 5.0 8.0 11 A 3
Short Circuit Detect V
Overvoltage Delay t
Undervoltage Delay t
Overcurrent Delay t
Short Circuit Delay t
Test Threshold V
Test Current I

SC

0.8 1 1.2 sec

OVD

90 100 110 ms

UVD

5 10 20 ms

OCD

SCD

TP

TST

Recovery Charge Current IRC 0.5 1 2

150 200 250 mV 1

80 100 120 ms

0.5 1.0 1.5 V

10 20 40 mA

mA

13

23

ELECTRICAL CHARACTERISTICS:

DS2760

TEMPERATURE, VOLTAGE, CURRENT (0°C to +50°C; 2.5V £ V

£ 5.5V)

DD

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Temperature Resolution T
Temperature Full Scale

T

LSB

FS

0.125

127

°C
°C

Magnitude
Temperature Error T
Voltage Resolution V
Voltage Full Scale

V

ERR

LSB

FS

±3 °C

5

4.88 mV

4.75 V
Magnitude
Voltage Offset Error V
Voltage Gain Error V

OERR

GERR

1 LSB 6
5 %V

reading

Current Resolution I

Current Full Scale
Magnitude
Current Offset Error I
Current Gain Error I

Accumulated Current
Resolution
Current Sampling

f

LSB

I

FS

OERR

GERR

q

CA

SAMP

0.625

15.625

1.9

2.56
64

mA

mV

A

3, 7

mV

3
4

4
1 LSB 8
3 1 %I

reading

0.25

6.25

mAhr

µVhr

3, 9, 14

4

3

4
1456 Hz

Frequency
Internal Timebase Accuracy t

ERR

±1 ±3

% 10

24

ELECTRICAL CHARACTERISTICS:

DS2760

1-WIRE INTERFACE (-20°C to +70°C; 2.5V £ V

£ 5.5V)

DD

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Time Slot t
Recovery Time t
Write 0 Low Time t
Write 1 Low Time t
Read Data Valid t
Reset Time High t
Reset Time Low t
Presence Detect High t
Presence Detect Low t
SWAP timing pulse width t
SWAP timing pulse

falling edge to

DC release

SWAP timing pulse rising

edge to

DC engage

60 120 ms

SLOT

1 ms

REC

60 120 ms

LOW0

1 15 ms

LOW1

15 ms

RDV

480 ms

RSTH

480 960 ms

RSTL

15 60 ms

PDH

60 240 ms

PDL

SWL

t

SWOFF

t

SWON

0.2 120 ms
0 1 ms 12

0 1 ms 12

DQ Capacitance CDQ 60 pF

EEPROM RELIABILITY SPECIFICATION (-20°C to +70°C; 2.5V £ VDD £ 5.5V)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Copy to EEPROM Time t
EEPROM Copy Endurance N

EEC

EEC

2 10 ms

25000 cycles 11

NOTES

1) All voltages are referenced to VSS.

2) See “Ordering Information” section of datasheet to determine corresponding part number for each V

3) Internal current sense resistor configuration.

4) External current sense resistor configuration.

5) Self heating due to output pin loading and sense resistor power dissipation can alter the reading from ambient conditions.

6) Voltage offset measurement is with respect to V

7) The current register supports measurement magnitudes up to 2.56A using the internal sense resistor option and 64mV with
the external resistor option. Compensation of the internal sense resistor value for process and temperature variation can
reduce the maximum reportable magnitude to 1.9A.

8) Current offset error null to ±1LSB typically requires 3.5s in-system calibration by user.

9) Current gain error specification applies to gain error in converting the voltage difference at IS1 and IS2, and excludes any
error remaining after the DS2760 compensates for the internal sense resistor’s temperature coefficient of 3700ppm/°C to
an accuracy of ±500ppm/°C. The DS2760 does not compensate for external sense resistor characteristics, and any error
terms arising from the use of an external sense resistor should be taken into account when calculating total current
measurement error.

10) Typical value for t

11) 4-year data retention at +70°C.

12) Typical load capacitance on

13) Test conditions are PLS = 4.1V, V

is at 3.6V and +25°C.

ERR

DC and CC is 1000pF.

DD

= 2.5V. Maximum current for conditions of PLS = 15V, VDD =0V is 10mA.

at +25°C.

OV

14) Error at time of shipment from Dallas Semiconductor is 3% max. Board mounting processes may cause the current gain

error to widen to as much as 10% for devices with the internal sense resistor option. Contact factory for on-board
recalibration procedure for devices with the internal sense resistor option to improve accuracy.

value.

OV

25