Datasheet

DS2746 Low-Cost 2-Wire Battery Monitor
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Figure 5. Measurement Timing
VOLTAGE MEASUREMENT
Battery voltage is measured at the V
IN
input with respect to V
SS
over a range of 0V to 4.997V (limited by VDD pin
voltage) and with a resolution of 2.44mV. The result is updated every 660ms with the average voltage over the last
220ms and placed in the VOLTAGE register in two’s compliment form. Voltages above the maximum register value
are reported as 7FFFh.
Figure 6. Voltage Register Format
MSB—Address 0Ch LSB—Address 0Dh
S 2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
X X X X
MSb LSb MSb LSb
“S”: sign bit(s), “X”: reserved Units: 2.44mV
The input impedance of V
IN
is sufficiently large (>15M) to be connected to a high impedance voltage divider in
order to support multiple cell applications. The pack voltage should be divided by the number of series cells to
present a single cell average voltage to the V
IN
input.