DS2782: Stand-Alone Fuel Gauge IC

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Figure 2. Block Diagram

SDA

2-Wire

Interface

BIAS/VREF

Timebase

Temp

&

Voltage

ADC

Current ADC

15 bit + sign

Rate,

Temperature

Compensation

EEPROM

Status

&

Control

Accumulated

Current

EN

SNS

VSS

VDD

SCL

PIO

VIN

DETAILED DESCRIPTION

The DS2782 operates directly from 2.5V to 5.5V and supports single cell Lithium-ion battery packs. As shown in

Figure 3, the DS2782 accommodates multicell applications by adding a voltage regulator for VDD and voltage

divider for VIN. Nonvolatile storage is provided for cell compensation and application parameters. Host side

development of fuel-gauging algorithms is eliminated. On-chip algorithms and convenient status reporting of

operating conditions reduce the serial polling required of the host processor.

Additionally, 16 bytes of EEPROM memory are made available for the exclusive use of the host system and/or

pack manufacturer. The additional EEPROM memory can be used to facilitate battery lot and date tracking and NV

storage of system or battery usage statistics.

Through its 2-Wire interface, the DS2782 gives the host system read/write access to status and control registers,

instrumentation registers, and general-purpose data storage. The 7-bit slave address is field programmable, thus

allowing up to 128 devices to be distinctly addressed by the host system. A unique, factory programmed 64-bit

registration number (8-bit family code + 48-bit serial number + 8-bit CRC) option assures that no two parts are alike

and enables absolute traceability.