DS2786B Datasheet, PDF (6/21 Pages) Maxim Integrated Products – Stand-Alone OCV-Based Fuel Gauge

Stand-Alone OCV-Based Fuel Gauge
Detailed Description
The DS2786B provides current-flow, voltage, and
temperature-measurement data to support battery-
capacity monitoring in cost-sensitive applications.
Current is measured bidirectionally over a dynamic
range of ±51.2mV with a resolution of 25µV. Assuming
a 15mΩ sense resistor, the current-sense range is
±3.4A, with a 1 least significant bit (LSB) resolution of
1.667mA. Current measurements are performed at reg-
ular intervals and each measurement is accumulated
internally to coulomb count host power consumption.
Each current measurement is reported with sign and
magnitude in the 2-byte Current Register. Battery-
voltage measurements are reported in the 2-byte
Voltage Register with 12-bit (1.22mV) resolution, and
auxiliary voltage measurements are reported in the 2-
byte Aux Volt Registers with 11-bit resolution.
Additionally, the Temperature Register reports tempera-
ture with 0.125°C resolution and ±3°C accuracy from
the on-chip sensor. The on-chip temperature measure-
ment is optional and replaces auxiliary voltage channel
AIN1. Figure 1 is the 2-wire bus timing diagram; Figure
2 is the DS2786B block diagram. Figure 3 is an appli-
cation example.
V_OUT
TEMPERATURE
MEASUREMENT
AIN1
Figure 2. Block Diagram
SWITCH IS ON WHEN AIN0 OR AIN1 IS BEING MEASURED.
BIAS
TIMEBASE
VOLTAGE
REFERENCE
ADC
STATE
MACHINE
EEPROM
2-WIRE
INTERFACE
1kΩ
V_DD
V_PROG
SDA
SCL
SNS
V_IN AIN0
1kΩ
V_SS
IC
GROUND
6 _______________________________________________________________________________________