Current-offset bias figure 7, Voltage measurement, Voltage register format figure 8 – Rainbow Electronics DS2770 User Manual
Page 11: Temperature measurement, Temperature register format figure 9, Timer
DS2770
11 of 27
CURRENT-OFFSET BIAS Figure 7
MSB—Address 32
LSB—Address 33
S
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
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
S
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
X
X
X
X
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
S
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
X
X
X
X
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.