DS2781
Figure 1. Block Diagram
VB
VDD
Voltage
Regulator
V
PIO
DQ
POR
BIAS/VREF
Timebase
EN
VIN
Temp
&
Voltage
Status
&
Control
1-Wire
Interface
OVD
ADC
Rate,
Temperature
Compensation
EEPROM
Accumulated
Current
Current ADC
15 bit + sign
SNS
VSS
DETAILED DESCRIPTION
The DS2781 operates directly from 2.5V to 10V and supports single or dual cell Lithium-ion battery packs.
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
non-volatile storage of system or battery usage statistics.
A Maxim 1-Wire interface provides serial communication at the standard 16kbps or overdrive 140kbps speeds
allows access to data registers, control registers and user memory. A unique, factory programmed 64-bit
registration number (8-bit family code + 48-bit serial number + 8-bit CRC) assures that no two parts are alike and
enables absolute traceability. The Maxim 1-Wire interface on the DS2781 supports multidrop capability so that
multiple slave devices may be addressed with a single pin.
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