BQ2040SN-C408 BENCHMARQ, BQ2040SN-C408 Datasheet - Page 25

• Manufacturer Part Number: BQ2040SN-C408
• Description: BATTERY CHARGE MONITOR, SMD, 2040
• Manufacturer: BENCHMARQ

Specifications of BQ2040SN-C408

• Battery Management Function: Charger, Status Monitor
• Battery Type: Li-Ion / NiCd / NiMH
• Supply Voltage Range: 3V To 6.5V
• Battery Ic Case Style: SOIC
• No. Of Pins: 16
• Operating Temperature Range: 0°C
• Interface Type: 2-Wire, Serial

Note:
Digital filter
Current integra-
tion gain
Self-discharge rate
Voltage gain
Reserved
EDVF charging
current
End of discharge
voltage 1
End-of-discharge
voltage final
Full charge
capacity
Hold-off time
EEPROM check 2 0x64
Reserved
t step
Description
1
1. Can be adjusted to calibrate the battery pack.
1
0x4d
Byte
0x4e
0x56 0x57
0x58 0x59
0x5a 0x5b
0x5c 0x5d
0x5e
0x60 0x61
0x62
0x63
0x65 0x7f
Low
0x4f
EEPROM
Address
Table 10. Example Register Contents (Continued)
High
Byte
0x5f
Byte
Low
EEPROM
Contents
96
40
2d
17
00
64
20
40
d0
00
b5
0f
Hex
High
Byte
d1
d4
07
00
00
07
0
320s hold-off The hold-off time is 320 - (byte value
12000mV
11200mV
Example
2000mA
0.30mV
3.2/0.05
Values
100mA
0.25%
7.09
181
20s
NA
0
25
Used to set the digital magnitude filter as described in
Table 2.
Represents the following: 3.2/sense resistor in ohms.
It is used by the bq2040 to scale the measured voltage
values on the SR pin in mA and mAh. This register
also compensates for variations in the reported sense
resistor value.
This packed field is the two’s complement of (52.73/x)
where x is the desired self-discharge rate per day (%)
at room temperature.
Voltage gain is packed as two units. For example, (R4
+ R5)/R4 = 7.09 would be stored as: whole number
stored in 0x57 as 7 and the decimal component stored
in 0x56 as 256 x 0.09 = 23(= 17h).
Should be programmed to 0.
Contains the desired charge current below EDVF.
The value programmed is the two’s complement of the
threshold voltage in mV.
The value programmed is the two’s complement of the
threshold voltage in mV.
This value sets the initial estimated pack capacity.
The t step for T/ t termination equals
320 - (byte value
Must be equal to 0xb5.
Not currently used by the bq2040.
20).
Notes
20).
bq2040