BQ2040_15 Datasheet, PDF (18/36 Pages) Texas Instruments – Gas Gauge IC With SMBus Interface

Not Recommended For New Designs
bq2040
End of Discharge Voltage1 (0x3e)
This read-only word returns the first end-of-discharge
voltage programmed for the pack.
Output: two’s complemented unsigned integer.
Returns battery end-of-discharge voltage pro-
grammed in EEPROM in mV.
End of Discharge VoltageF (0x3f)
This read-only word returns the final end-of-discharge
voltage programmed for the pack.
Output: two’s complemented unsigned integer.
Returns battery final end-of-discharge voltage pro-
grammed in EEPROM in mV.
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:
FLAGS2 Bits
7
6543210
DMODE -
-
-
-
-
-
-
Where DMODE is:
0 Selects Absolute display
1 Selects Relative display
Bit 6 reflects the high/low state of PSTAT. PSTAT ≥1.5V
generates a charge suspend condition.
The PSTAT value is:
FLAGS2 Bits
7
6
5
4
3
2
1
0
- PSTAT -
-
-
-
-
-
Where PSTAT is:
0 PSTAT input < 1.0V
1 PSTAT input ≥ 1.5V
The Chemistry flag (CHM), bit 5, selects Li-Ion or nickel
compensation factors.
The CHM value is:
FLAGS2 Bits
76
5
43210
-
- CHM -
-
-
-
-
Where CHM is:
0 Selects Nickel
1 Selects Li-Ion
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:
76
-
-
FLAGS2 Bits
5
43210
-
CC -
-
-
-
Where CC is:
0 RM is not modified on valid bq2040
charge termination
1 RM is set to a programmable percentage of
the FCC when a valid bq2040 charge termi-
nation occurs
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:
76
-
-
FLAGS2 Bits
5
43210
-
-
- OV -
-
Where OV is:
0 Voltage < 1.05 ∗ ChargingVoltage
1 Voltage ≥ 1.05 ∗ ChargingVoltage
Bit 1, the Low Temperature Fault flag (LTF), is set when
Temperature is < 12°C and cleared when Temperature
is ≥ 15°C.
The LTF value is:
FLAGS2 Bits
76
5
43210
-
-
-
-
-
- LTF -
18