The Texas Instruments bq27425-G2 fuel gauge is an easy-to-configure microcontroller peripheral that provides system-side fuel gauging for single-cell Li-Ion batteries. The device requires minimal user configuration and system microcontroller firmware development.
The fuel gauge uses the patented Impedance Track™ algorithm for fuel gauging, and provides information such as remaining battery capacity (mAh), state-of-charge (%), and battery voltage (mV).
Battery fuel gauging with the bq27425-G2 fuel gauge requires connections only to PACK+ (P+) and PACK– (P–) for a removable battery pack or embedded battery circuit. The 15-pin, 2.69 mm × 1.75 mm, 0.5-mm pitch chip scale package (DSBGA) is ideal for space-constrained applications.
DEVICE NAME | PACKAGE | BODY SIZE (NOM) |
---|---|---|
bq27425-G2 | DSBGA (15) | 2.69 mm × 1.75 mm |
Changes from A Revision (February 2013) to B Revision
Changes from * Revision (October 2012) to A Revision
PART NUMBER | BATTERY TYPE | CHEM_ID (1) | FIRMWARE VERSION (2) | COMMUNICATION FORMAT |
---|---|---|---|---|
bq27425YZFR-G2A | LiCoO2
(4.2 V maximum charge) |
0x128 | 2.05 (0x0205) |
I2C |
bq27425YZFT-G2A | ||||
bq27425YZFR-G2B | LiMn2O4
(4.3 to 4.35 V maximum charge) |
0x312 | ||
bq27425YZFT-G2B |
PIN | I/O(1) | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
BAT | E2 | I | Cell-voltage measurement input. ADC input. Recommend 4.8 V maximum for conversion accuracy. |
BIN | C3 | I | Battery-insertion detection input. A logic high-to-low transition is detected as a battery insertion event. Recommend using a pullup resistor >1 MΩ (1.8 MΩ, typical) to VCC for reduced power consumption. An internal pullup resistor option is also available using the Operation Configuration [BI_PU_EN] register bit. |
CE | D2 | I | Chip Enable. Internal LDO is disconnected from REGIN when driven low. |
GPOUT | A2 | O | General Purpose open-drain output. May be configured as a Battery Low indicator or perform SOC interrupt (SOC_INT) function. |
NC | A1, B2 | NA | No internal connection. May be left floating. |
C2, D3, E3 | IO | Reserved for factory use. Must be left floating for proper operation. | |
REGIN | E1 | P | Regulator input. Decouple with 0.1-μF ceramic capacitor to VSS. |
SCL | A3 | I | Slave I2C serial communications clock input line for communication with system (Master). Use with 10-kΩ pullup resistor (typical). |
SDA | B3 | I/O | Slave I2C serial communications data line for communication with system (Master). Open-drain IO. Use with 10-kΩ pullup resistor (typical). |
SRX | B1 | IA | Integrated Sense Resistor and Coulomb Counter input typically connected to battery PACK– terminal. For best performance decouple with 0.1-μF ceramic capacitor to VSS. |
VCC | D1 | P | Regulator output and bq27425 processor power. Decouple with 1-μF ceramic capacitor to VSS. |
VSS | C1 | P, IA | Device ground and Integrated Sense Resistor termination. |