Texas Instruments BQ294524DRVR

Overview

BQ294524DRVR from Texas Instruments is a secondary overvoltage protection IC for 3-series Li-ion battery packs, monitoring V1–VSS, V2–V1, and V3–V2 independently with ±10 mV accuracy, fixed 4.45 V OVP threshold, 6.5 s delay, and low 1 µA supply current. It drives an external N-channel FET to trigger fuse blow in tablet and power tool battery packs.

For engineers reviewing the BQ294524DRVR datasheet, BQ294524DRVR pinout, BQ294524DRVR application, or BQ294524DRVR equivalent, key selection criteria include confirmed 3-cell support, factory-programmed 4.45 V / 6.5 s OVP timing, SON-6 package thermal performance, and integration with NMOS-based secondary protection circuits requiring <100 nA per-cell leakage.

Technical Context

The BQ294524DRVR implements independent analog voltage sensing per cell via internal multiplexer, comparing each differential input against a fixed 4.45 V reference with 300 mV hysteresis. Its delay timer is hardwired to 6.5 s (typ), non-adjustable, and activates only when any monitored cell exceeds VOV for the full duration.

Operation requires external RC filters on all Vx inputs (RIN = 100–4700 Ω, CIN = 0.1–1 µF) and VDD (RVD/CVD). The OUT pin delivers active-high drive capable of sourcing ≥4.5 mA at VDD – 0.2 V to gate an external NMOS, with output rise time ≤5 µs into 1 nF load.

Key Specifications

Pinout & Package

6-pin SON package (2.00 mm × 2.00 mm) with exposed thermal pad (PWRPAD) electrically connected to VSS and required to be soldered to PCB ground plane for thermal and functional integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ294524DRVR, BQ294522DRVR offers faster response but less noise immunity, while BQ294533DRVR raises the protection threshold-both require revalidation of fuse blow energy and timing coordination with primary protection layers.

Availability

BQ294524DRVR is available at Aetrix Electronics and suitable for tablet battery packs, power tool battery systems, and portable medical instrumentation requiring stable component supply with guaranteed long-term manufacturability.

Supply support for BQ294524DRVR 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 specializing in analog and embedded processing technologies, with leadership in battery management and power ICs.

The bq2945xx family was designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, delivering factory-programmed, hardware-based safety without software dependency.

FAQ

What is the exact overvoltage protection threshold and delay time for BQ294524DRVR?

The BQ294524DRVR has a factory-programmed overvoltage protection threshold of 4.45 V ±10 mV and a fixed delay time of 6.5 seconds (typical), with min/max specification of 5.2 s to 7.8 s across –40°C to +110°C. These values are laser-trimmed during manufacturing and cannot be adjusted externally. The BQ294524DRVR uses this fixed timing to ensure deterministic secondary protection behavior independent of system firmware.

How does BQ294524DRVR interface with the external MOSFET in a battery pack?

The BQ294524DRVR drives the gate of an external N-channel MOSFET via its active-high OUT pin, which sources ≥4.5 mA at VDD – 0.2 V. When any monitored cell exceeds 4.45 V for the full 6.5 s delay, OUT transitions high to turn on the NMOS, creating a low-impedance path from fuse to Pack– and enabling battery/charger current to blow the fuse. The BQ294524DRVR resets OUT low only after all cell voltages fall below 4.45 V minus 300 mV hysteresis.

Can BQ294524DRVR be used in 2-cell battery configurations?

Yes, BQ294524DRVR supports 2-cell (2S) configurations: V3 must be shorted to V2 per TI's application guidance, leaving V1, V2, and VSS active to monitor V1–VSS and V2–V1. All electrical specifications-including 4.45 V OVP, 6.5 s delay, and 1 µA supply current-remain valid. The BQ294524DRVR maintains the same pinout and external component requirements (RIN/CIN on V1/V2, RVD/CVD on VDD) in both 2S and 3S modes.

What are the mandatory layout requirements for BQ294524DRVR to ensure reliable operation?

Reliable BQ294524DRVR operation requires: (1) PWRPAD soldered to solid PCB ground plane for thermal stability and noise immunity; (2) RIN/CIN filters placed within 2 mm of each Vx pin; (3) VSS routed directly to Pack– with minimal trace length; and (4) OUT trace sized to handle fuse-blow current without voltage drop. These practices prevent measurement error, thermal shutdown, or false OVP triggering. The BQ294524DRVR datasheet specifies these as non-negotiable for production designs.

Does BQ294524DRVR support customer test mode (CTM), and how is it activated?

Yes, BQ294524DRVR supports Customer Test Mode (CTM) to verify OVP timing during pack assembly. CTM is activated by applying VDD at least 10 V higher than V3-e.g., V3 = 12.6 V (3 × 4.2 V), VDD ≥ 22.6 V. This reduces the delay to ~15 ms for rapid functional testing. CTM exits automatically when the VDD–V3 differential drops below 10 V. The BQ294524DRVR datasheet warns against exceeding absolute maximum ratings during CTM to prevent permanent damage.