Maxim MAX846AC-D, MAX846AEEE Datasheet

19-1121; Rev 0; 9/96

EVALUATION KIT

AVAILABLE

Cost-Saving Multichemistry

Battery-Charger System

_______________General Description

The MAX846A is a cost-saving multichemistry battery­charger system that comes in a space-saving 16-pin
QSOP. This integrated system allows different battery
chemistries (Li-Ion, NiMH or NiCd cells) to be charged
using one circuit.

In its simplest application, the MAX846A is a stand­alone, current-limited float voltage source that charges
Li-Ion cells. It can also be paired up with a low-cost
microcontroller (µC) to build a universal charger capa­ble of charging Li-Ion, NiMH, and NiCd cells.

An internal 0.5%-accurate reference allows safe charg­ing of Li-Ion cells that require tight voltage accuracy.
The voltage- and current-regulation loops used to con­trol a low-cost external PNP transistor (or P-channel
MOSFET) are independent of each other, allowing more
flexibility in the charging algorithms.

The MAX846A has a built-in 1%, 3.3V, 20mA linear regu­lator capable of powering the µC and providing a refer­ence for the µC’s analog-to-digital converters. An
on-board reset notifies the controller upon any unex­pected loss of power. The µC can be inexpensive, since
its only functions are to monitor the voltage and current
and to change the charging algorithms.

________________________Applications

Li-Ion Battery Packs
Desktop Cradle Chargers
Li-Ion/NiMH/NiCd Multichemistry Battery

Chargers
Cellular Phones
Notebook Computers
Hand-Held Instruments

__________________Pin Configuration

TOP VIEW

DCIN

CCI
GND
CCV

VSET

ISET

OFFV

1

VL

2
3

MAX846A

4
5
6
7
8

QSOP

DRV

16

PGND

15
14

CS-
CS+

13
12

BATT

11

ON

10

CELL2

9

PWROK

____________________________Features

♦ Multichemistry Charger System (Li-Ion, NiMH, NiCd)
♦ Independent Voltage and Current Loops
♦ ±0.5% Internal Reference for Li-Ion Cells
♦ Lowers Cost:

—Stands Alone or Uses Low-Cost µC
—Built-In 1% Linear Regulator Powers µC
—Linear Regulator Provides Reference to µC ADCs
—Built-In µC Reset
—Controls Low-Cost External PNP Transistor or

P-Channel MOSFET

♦ Space-Saving 16-Pin QSOP
♦ Charging-Current-Monitor Output
♦ <1µA Battery Drain when Off

______________Ordering Information

PART

MAX846AC/D
MAX846AEEE -40°C to +85°C

*Dice are tested at TA= +25°C only. Contact factory for details.

TEMP. RANGE PIN-PACKAGE

0°C to +70°C

Dice*
16 QSOP

__________Typical Operating Circuit

3.5V
TO

20V

DRV

CS­CS+
DCIN

ISET

CELL2

GND

PGND

MAX846A

BATT

CCV

CCI

PWROK

Li-ION
BATTERY

VL

ON

MAX846A

________________________________________________________________

Maxim Integrated Products

1

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone]

Cost-Saving Multichemistry
Battery-Charger System

ABSOLUTE MAXIMUM RATINGS

DCIN, DRV, CS+, CS-, BATT to GND........................-0.3V, +21V

PGND to GND.....................................................................±0.3V

VL to GND......................................................................-0.3V, 7V

................................................................................10mA

I

PWROK

PWROK, ISET, CCI, CCV, OFFV, VSET,

CELL2, ON to GND............................................-0.3V, VL + 0.3V

CS+ to CS-..........................................................................±0.3V

VL Short to GND.........................................................Continuous

...................................................................................100mA

I

DRV

MAX846A

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

(V

= 10V, ON = VL, IVL= I

DCIN

otherwise noted. Typical values are at T

VL REGULATOR

REFERENCE

Output Voltage

CURRENT-SENSE AMPLIFIER

Transconductance V
Output Offset Current V
Input Common-Mode Range Measured at V

Maximum Differential Input Voltage

CS- Lockout Voltage
CS+, CS- Input Current V

CS+, CS- Off Input Current DCIN = VL = ON = GND 0.01 10

= 0mA, VCS- = V

VSET

A

= 10V, V

= +25°C.)

CS+

V

= 20V, I

DCIN

0mA < IVL< 20mA, 3.7V < V
VL = GND
Rising VL edge, 2% hysteresis

Measured at VSET, I

= 1.7V, V

ISET

= 4V 3

CS+

V

= V

CS-

CSA transconductance >0.9mA/V
When V

disabled.

CS+

= 2.1V,

ISET

is less than this voltage, DRV is

CS-

= 20V, V

Continuous Power Dissipation (T

QSOP (derate 8.3mW/°C above +70°C)........................667mW

Operating Temperature Range

MAX846AEEE ....................................................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec).............................+300°C

= 4.5V, V

BATT

CONDITIONS

= IVL= 0mA mA5DCIN Supply Current

DRV

VSET

- V

CS+

CS-

, V

- V

CS+

CS-

CS+-VCS-

= 165mV 250

DCIN

= 0mA, VON= 0V

= 165mV 0.95 1 1.05 mA/V

CS-

= V

OFFV

< 20V

= 165mV 2.1 20.0 V

= 0V, TA= 0°C to +85°C, unless

CELL2

= +70°C)

A

225 mV

1.9 2.1 V

UNITSMIN TYP MAXPARAMETER

V3.7 20.0Operating Range
V3.267 3.305 3.333Output Voltage

mA50Short-Circuit Current Limit

V2.9 3.0 3.1PWROK Trip Level
V2.5 2.9VL Undervoltage-Lockout Level

V-0.5% 1.650 +0.5%

kΩ-2% 20 +2%Output Resistance

µA

µA
µA

2 _______________________________________________________________________________________

Cost-Saving Multichemistry

Battery-Charger System

ELECTRICAL CHARACTERISTICS (continued)

(V

= 10V, ON = VL, IVL= I

DCIN

otherwise noted. Typical values are at T

VOLTAGE LOOP

Voltage-Loop Set Point

BATT Input Current

CURRENT LOOP

Current-Loop Set Point I
CA Voltage Gain 5
CCI Output Impedance 50 kΩ

Overcurrent Trip Level

DRIVER

DRV Sink Current V
DRV Off Current V

LOGIC INPUTS AND OUTPUTS

Input High Level CELL2, ON, OFFV 2.4 VL V
Input Low Level CELL2, ON, OFFV 0 0.8 V
Input Current CELL2, ON, OFFV 0.01 1
PWROK Output Low Level I
PWROK Output High Leakage V

= 0mA, VCS- = V

VSET

A

= +25°C.)

V

VSET

V

DRV

V

VSET

V

DRV

1mA < I
V

BATT

V

BATT

DRV

When V
is disabled.

DRV
DRV

PWROK

PWROK

= 10V, V

CS+

= 1.650V, V

= 10V

= 1.650V, V

= 10V

< 5mA

DRV

= 10V, CELL2 = GND or VL
= 10V, ON = GND, CELL2 = GND or VL

= 5mA, V

= 3V 20 mA
= 20V, VON= 0V 0.1 100

DRV

exceeds this voltage, DRV current

ISET

= 1mA, V

= 3.3V 0.01 1

= 4.5V, V

BATT

CONDITIONS

= 0V, I

CELL2

CELL2

= 10V

DCIN

DRV

= VL, I

DRV

= VVL= 2.5V 0.4 V

= V

OFFV

= 1mA,

= 1mA,

MAX846A

= 0V, TA= 0°C to +85°C, unless

CELL2

-0.25% 4.2 +0.25%

-0.25% 8.4 +0.25%

0.05Voltage-Loop Load Regulation

0.01 1BATT Off Input Current

1.634 1.650 1.666 V

1.90 2.1 V

225

MAX846A

UNITSMIN TYP MAXPARAMETER

V

V1.25 2.0VSET Common-Mode Input Range

kΩ150CCV Output Impedance

%

µA
µA

V/V

µA

µA

µA

_______________________________________________________________________________________ 3

Cost-Saving Multichemistry
Battery-Charger System

ELECTRICAL CHARACTERISTICS (Note 1)

(V

= 10V, ON = VL, IVL= I

DCIN

otherwise noted.)

= 0mA, VCS- = V

VSET

CS+

= 10V, V

BATT

= 4.5V, V

OFFV

= V

= 0V, TA= -40°C to +85°C, unless

CELL2

CONDITIONS

VL REGULATOR

V

DCIN

= 20V, I

DRV

= IVL= 0mA mA5DCIN Supply Current

0mA < IVL< 20mA, 3.7V < V

MAX846A

Rising VL edge, 2% hysteresis

REFERENCE

Measured at VSET, I

= 0mA, VON= 0V

VSET

CURRENT-SENSE AMPLIFIER

Transconductance V
Output Offset Current V
CS+, CS- Off Input Current V

ISET
CS+
ON

= 1.7V, V
= 4V

= 0V, V

CS+

CS+

= V

- V

= 165mV

CS-

= 10V 10

CS-

VOLTAGE LOOP

V

Voltage-Loop Set Point

BATT Off Input Current V

= 1.650V, V

VSET

V

= 10V

DRV

V

= 1.650V, V

VSET

V

= 10V

DRV

= 10V, ON = GND, CELL2 = GND or VL 1

BATT

CELL2

CELL2

= 0V, I

= VL, I

CURRENT LOOP

Current-Loop Set Point I
Overcurrent Trip Level

= 5mA, V

DRV

When V

ISET

is disabled.

= 10V 1.625 1.675 V

DRV

exceeds this voltage, DRV current

DRIVER

DRV Sink Current V
DRV Off Current

= 3V 20 mA

DRV

V

= 20V, ON = GND 100

DRV

Note 1: Specifications to -40°C are guaranteed by design and not production tested.

< 20V

DCIN

= 1mA,

DRV

MAX846A

= 1mA,

DRV

UNITSMIN TYP MAXPARAMETER

-2% 20 +2%Output Resistance

kΩ

0.93 1.07 mA/V
5

µA
µA

-0.35% 4.2 +0.35%

-0.35% 8.4 +0.35%
µA

1.86 2.14 V

µA

V3.259 3.341Output Voltage
V2.9 3.1PWROK Trip Level
V2.5 3.0VL Undervoltage-Lockout Level

V-0.7% 1.650 +0.7%Output Voltage

V

4 _______________________________________________________________________________________