Texas Instruments BQ294522DRVR

Overview

BQ294522DRVR from Texas Instruments is a secondary overvoltage protection IC for 2- or 3-series Li-ion battery packs, featuring fixed 4.45 V OVP threshold, 4 s fault detection delay, ±10 mV accuracy, 1 µA supply current, and 6-pin WSON package. It independently monitors each cell voltage and drives an external N-channel FET to trigger fuse blow during overvoltage events in portable power tools and notebooks.

For engineers reviewing the BQ294522DRVR datasheet, BQ294522DRVR pinout, BQ294522DRVR application, or BQ294522DRVR equivalent, key selection criteria include OVP threshold tolerance, delay time stability across temperature, low leakage per cell input (<100 nA), thermal pad grounding requirement, and compatibility with 2-/3-cell stack configurations using discrete NMOS switching.

Technical Context

The BQ294522DRVR implements independent analog sensing of V1–VSS, V2–V1, and V3–V2 differential voltages via internal multiplexer, comparing each against a factory-programmed 4.45 V overvoltage threshold. Detection triggers a fixed 4 s delay timer before asserting high-level OUT signal.

Its functional architecture includes integrated oscillator-based timing, hysteresis (300 mV typical) to prevent chatter near threshold, and output drive capable of sourcing ≥4.5 mA into short-circuit while maintaining VOH ≥ VDD – 0.2 V across –40°C to +110°C ambient.

Key Specifications

Pinout & Package

Package: 6-pin WSON (DRV), 2.00 mm × 2.00 mm body size, exposed thermal pad (PWRPAD) requiring PCB connection to VSS for proper thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar overvoltage protection applications.

Compared with BQ294522DRVR, BQ294524DRVR extends fault confirmation time to reduce nuisance trips, while BQ294532DRVR raises the protection threshold for advanced NMC or silicon-anode cells - both retain identical pinout, package, and thermal pad requirements.

Availability

BQ294522DRVR is available at Aetrix Electronics and suitable for power tools, notebook computers, tablets, and portable medical instruments requiring stable component supply and long-term lifecycle support.

Supply support for BQ294522DRVR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The BQ2945xx product line is designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, emphasizing precision threshold accuracy, ultra-low power consumption, and robust operation across extended temperature ranges.

FAQ

What is the overvoltage protection threshold and accuracy of the BQ294522DRVR?

The BQ294522DRVR has a factory-programmed overvoltage protection threshold of 4.45 V with ±10 mV accuracy at 25°C. This specification is guaranteed across the full operating temperature range of –40°C to +110°C, and the device includes 300 mV typical hysteresis to prevent oscillation near the trip point. The BQ294522DRVR achieves this precision without external components, simplifying design and improving reliability in safety-critical battery applications.

How does the BQ294522DRVR interface with the battery pack and external FET?

The BQ294522DRVR connects directly to the battery stack via V1, V2, and V3 sense inputs, measuring differential voltages across each cell. Its OUT pin drives the gate of an external N-channel MOSFET, pulling high after the 4 s delay when overvoltage is detected. The FET then shorts the fuse to ground, enabling battery or charger current to blow the fuse. The BQ294522DRVR requires the PWRPAD thermal pad to be connected to VSS on the PCB for correct operation and thermal stability.

What is the purpose of Customer Test Mode (CTM) in the BQ294522DRVR?

Customer Test Mode (CTM) in the BQ294522DRVR reduces production test time by enabling rapid validation of the overvoltage delay timer. Entering CTM requires applying VDD at least 10 V higher than V3, which activates a shortened internal delay (>15 ms) instead of the full 4 s. This allows functional verification of the timing circuit without waiting for extended test cycles, while maintaining full electrical safety margins. The BQ294522DRVR exits CTM automatically when the VDD–V3 differential drops below threshold.

Can the BQ294522DRVR be used in both 2-cell and 3-cell Li-ion battery configurations?

Yes, the BQ294522DRVR supports both 2-series and 3-series Li-ion battery configurations. In a 3-cell setup, V1, V2, and V3 connect to each cell's positive terminals, with VSS tied to the stack's negative terminal. For 2-cell use, V3 is connected to V2, effectively disabling the third channel while retaining full monitoring of the lower two cells. The BQ294522DRVR maintains identical OVP accuracy, delay timing, and output drive capability in both configurations.

What are the key PCB layout requirements for reliable operation of the BQ294522DRVR?

Reliable operation of the BQ294522DRVR requires placing RC filters (RIN/CIN) as close as possible to V1, V2, V3, and VDD pins to minimize noise coupling; routing VSS directly to the battery's negative terminal and connecting it to the exposed PWRPAD thermal pad; and ensuring the trace from OUT to the NMOS gate can handle surge current during fuse blow. The BQ294522DRVR datasheet specifies minimum trace widths and recommends avoiding vias in critical sense paths to preserve measurement integrity.