The bq20851-v1p2 is a SBS-compliant fuel gauge IC from TI for battery pack installation that maintains an accurate record of available charge in Li-ion or Li-polymer batteries. The bq20851-v1p2 monitors capacity and other critical parameters of the battery pack and reports the information to the system host controller over a serial communication bus. It is designed to work with the bq29311 analog front-end (AFE) protection IC to maximize function.
The bq20851‑V1P2 provides accurate measurement of battery charge, voltage, temperature and remaining capacity for 10.8‑V or 14.4‑V packs. It integrates a 16‑bit sigma‑delta ADC, a 512‑byte flash memory for configuration, and supports the Smart Battery Specification (SBS) V1.1 via SMBus.
The device is supplied in a 38‑pin TSSOP (DBT) package, operates from –20 °C to 85 °C, and includes features such as self‑calibration, offset error < 1 µV, and a resolution better than 3 nV·h. Electrical characteristics, timing specifications, and mechanical dimensions are detailed in the data sheet.
| Package Type | 38‑pin TSSOP (DBT) |
|---|---|
| Operating Temperature Range | -20 °C to 85 °C |
| Supply Voltage Range | -0.3 V to 6 V |
| Flash Memory Size | 512 bytes |
| Resolution (Current Measurement) | better than 3 nV·h |
| Offset Measurement Error | < 1 µV (typical) |
| SMBus Frequency | 10 kHz – 100 kHz |
It is supplied in a 38‑pin TSSOP (DBT) package.
The device includes 512 bytes of internal data flash memory for configuration storage.
It operates from –20 °C to 85 °C.
SMBus clock frequencies from 10 kHz up to 100 kHz are supported.