The bq2941x is a secondary overvoltage protection IC for 2-, 3-, or 4-cell lithium-ion battery packs that incorporates a high-accuracy precision overvoltage detection circuit. It includes a programmable delay circuit for overvoltage detection time.
The bq2941x family consists of secondary overvoltage protection integrated circuits designed for 2-, 3-, or 4-cell lithium-ion battery packs. These devices incorporate a high-accuracy precision overvoltage detection circuit and include a programmable delay circuit to prevent false triggering during pulse charge operations.
Each cell in the pack is compared against an internal reference voltage specific to the model (bq29410: 4.35 V, bq29411: 4.40 V, bq29412: 4.45 V). Upon detecting an overvoltage condition, the device charges an external capacitor connected to the CD pin. When this voltage reaches 1.2 V, the OUT pin activates a high level to trigger an external N-channel FET and blow an external fuse in the positive battery rail.
| Overvoltage detection voltage (bq29410) | 4.35 V |
|---|---|
| Overvoltage detection voltage (bq29411) | 4.40 V |
| Overvoltage detection voltage (bq29412) | 4.45 V |
| Low power consumption Icc | < 2 µA |
| Operating ambient temperature range | -40°C to 110°C |
The fixed high accuracy overvoltage protection threshold for the bq29410 is 4.35 V.
The device starts charging an external capacitor through the CD pin when a cell reaches an overvoltage condition.
An external capacitor connected to this pin determines the programmable delay time for overvoltage detection.