3-5 cell Li-ion protection in a 20-TSSOP footprint
The BQ7790522PWR is a battery protection IC from Texas Instruments designed for 3 to 5 series-connected lithium-ion cells. It integrates overcurrent, over/under voltage, short circuit, and overtemperature fault protection into a single 20-TSSOP package. Operating across -40°C to 85°C, this part suits portable power tools, e-bike battery packs, energy storage systems, and other multi-cell Li-ion applications where a dedicated protection controller is required to meet safety standards.
What the fault-protection set means for your BOM
The overcurrent and short-circuit detection thresholds are set internally — the part latches off when a fault is detected, and the recovery behavior depends on the specific variant's timing. The over/under voltage protection monitors each cell independently, which is critical for preventing cell imbalance damage in a 3-5 series stack. The overtemperature protection uses an internal sensor, so the IC's own die temperature is the trip point — not the cell temperature. If the application sees high ambient heat from nearby power FETs, a separate NTC on the pack may still be needed for cell-level thermal monitoring.
Active production — no last-time-buy pressure
ROHS3 compliant per the lifecycle entry, so it passes EU material restrictions without an exemption. For a BOM line that needs a multi-cell Li-ion protector, this part is still a valid design-in choice — no migration planning required yet.
Package and supply-chain note
The 20-TSSOP package (4.40 mm body width) is a standard footprint for this pin count. Available in Tape & Reel for automated assembly or Cut Tape for prototyping — the reel quantity is set by TI's standard packaging, so confirm the MOQ at RFQ.