BQ2040SN-C408 BENCHMARQ, BQ2040SN-C408 Datasheet - Page 18

• 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

bq2040
End of Discharge Voltage1 (0x3e)
This read-only word returns the first end-of-discharge
voltage programmed for the pack.
End of Discharge VoltageF (0x3f)
This read-only word returns the final end-of-discharge
voltage programmed for the pack.
FLAGS1&2() (0x2f)
This read-only register returns an unsigned integer rep-
resenting the internal status registers of the bq2040.
The MSB represents FLAGS2, and the LSB represents
FLAGS1. See Table 6 for the bit description for FLAGS1
and FLAGS2.
FLAGS2
The Display Mode flag (DMODE), bit 7 determines
whether the bq2040 displays Relative or Absolute capac-
ity.
The DMODE value is:
Where DMODE is:
Bit 6 reflects the high/low state of PSTAT. PSTAT 1.5V
generates a charge suspend condition.
The PSTAT value is:
Where PSTAT is:
The Chemistry flag (CHM), bit 5, selects Li-Ion or nickel
compensation factors.
DMODE
7
Output: two’s complemented unsigned integer.
Returns battery end-of-discharge voltage pro-
grammed in EEPROM in mV.
Output: two’s complemented unsigned integer.
Returns battery final end-of-discharge voltage pro-
grammed in EEPROM in mV.
0
1
0
1
-
7
Selects Absolute display
Selects Relative display
PSTAT input < 1.0V
PSTAT input
PSTAT
6
6
-
5
5
-
-
FLAGS2 Bits
FLAGS2 Bits
1.5V
4
4
-
-
3
3
-
-
2
2
-
-
1
1
-
-
0
0
-
-
18
The CHM value is:
Where CHM is:
Bit 4, the Charge Control flag (CC), determines whether
a bq2040-based charge termination will set RM to a
user-defined programmable full charge capacity.
The CC value is:
Where CC is:
Bit 3 is reserved.
Bit 2, the Overvoltage flag (OV), is set when the bq2040
detects a pack voltage 5% greater than the programmed
charging voltage. This bit is cleared when the pack volt-
age falls 5% below the programmed charging voltage.
The OV value is:
Where OV is:
Bit 1, the Low Temperature Fault flag (LTF), is set when
Temperature is < 12°C and cleared when Temperature
is
The LTF value is:
7
0
1
7
0
1
7
0
1
7
-
-
-
-
15°C.
Selects Nickel
Selects Li-Ion
RM is not modified on valid bq2040
charge termination
RM is set to a programmable percentage of
the FCC when a valid bq2040 charge termi-
nation occurs
Voltage < 1.05
Voltage
6
6
6
-
-
6
-
-
CHM
1.05
5
5
5
-
-
5
-
FLAGS2 Bits
FLAGS2 Bits
FLAGS2 Bits
FLAGS2 Bits
ChargingVoltage
ChargingVoltage
CC
4
4
4
-
4
-
-
3
3
3
-
-
3
-
-
OV
2
2
2
-
2
-
-
LTF
1
1
1
-
-
1
-
0
0
0
-
-
0
-
-