DS2764AE+ Maxim Integrated Products, DS2764AE+ Datasheet - Page 12

• Manufacturer Part Number: DS2764AE+
• Description: IC MON BATT LI-ION HP 16-TSSOP
• Manufacturer: Maxim Integrated Products

Specifications of DS2764AE+

• Function: Battery Monitor
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

CURRENT OFFSET COMPENSATION
The current measurement and current accumulation are internally compensated for offset on a continual basis
minimizing error resulting from variations in device temperature and voltage. Additionally, the Current Offset Bias
register is a user programmable constant bias that can be used to alter the offset of the Current and Accumulated
current registers. User programmed bias values can be used to correct for offset errors after final assembly of the
module or pack. An offset value can be purposely chosen to bias current accumulation in the discharge polarity to
ensure a pessimistic accounting of A level standby currents.
The Current Offset Bias value resides in EEPROM address 33h in two’s-complement format and is subtracted from
current measurements during the accumulation process. The Current Offset Bias is applied to the internal and
external sense resistor configurations. The factory default for EEPROM address 33h is 0.
Figure 7. Current Offset Bias
VOLTAGE MEASUREMENT
The DS2764 continually measures the voltage between pins V
register is updated in two’s-complement format every 3.4ms with a 4.88mV resolution. Voltages above the
maximum register value are reported as the maximum value. Figure 8 shows the voltage register format.
Figure 8. Voltage Register Format
TEMPERATURE MEASUREMENT
The DS2764 uses an integrated temperature sensor to continually measure battery temperature. Temperature
measurements are placed in the temperature register every 220ms in two’s-complement format with a 0.125°C
resolution over a 127°C range. Figure 9 shows the temperature register format.
Figure 9. Temperature Register Format
MSb
MSb
S
S
2
2
9
9
2
2
MSB—Address 0C
MSB—Address 18
8
8
2
2
7
7
2
2
6
6
MSb
S
2
2
5
5
2
6
2
2
4
4
2
Units: 0.625mA for Internal Sense Resistor
5
LSb
LSb
2
2
Address 33
3
3
15.625V for External Sense Resistor
12 of 20
2
4
2
3
MSb
MSb
2
2
2
2
IN
2
2
and V
2
2
1
1
2
1
SS
2
2
LSB—Address 0D
LSB—Address 19
LSb
0
0
over a 0 to 4.75V range. The voltage
2
0
X
X
X
X
X
X
Units: 0.125C
Units: 4.88mV
X
X
LSb
LSb
X
X