DS2770

11 of 27

CURRENT-OFFSET BIAS Figure 7

MSB—Address 32

LSB—Address 33

MSb

LSb

MSb

LSb

Units: 0.0625mA for internal sense resistor

1.5625

mV for external sense resistor

VOLTAGE MEASUREMENT

The DS2770 continuously measures the voltage between pins VIN and VSS with a resolution of 4.88mV

over a range of 0V to 4.992V. Measurement data is updated every 55ms and placed in the Voltage

Register in two’s complement format. Voltages above the maximum register value are reported as the

maximum value. Figure 8 shows the Voltage Register format.

VOLTAGE REGISTER FORMAT Figure 8

MSB—Address 0C

LSB—Address 0D

XXXX

X

MSb

LSb

MSb

LSb

Units: 4.88mV

TEMPERATURE MEASUREMENT

The DS2770 uses an integrated temperature sensor to continually measure battery temperature with a

resolution of 0.125°C. Temperature measurements are updated every 55ms and placed in the Temperature

Register in two’s complement format. Figure 9 shows the Temperature Register format.

TEMPERATURE REGISTER FORMAT Figure 9

MSB—Address 18

LSB—Address 19

XXXX

X

MSb

LSb

MSb

LSb

Units: 0.125

°C

TIMER

The DS2770 provides a general-purpose timer with a range of 1024h. The timer count is stored in the

Elapsed Time Register with a resolution of approximately 56s. The count will roll over to zero when it

reaches its maximum value and begin counting up again. Additionally, the user can write any desired

value to the register. Figure 10 shows the Elapsed Time Register format.