Texas Instruments BQ294524DRVT

Overview

BQ294524DRVT from Texas Instruments is a secondary overvoltage protection IC for 3-series Li-ion battery packs, featuring a fixed 4.45 V OVP threshold, 6.5 s fault detection delay, ±10 mV accuracy, and 1 µA quiescent current. 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 notebook computers.

For engineers reviewing the BQ294524DRVT datasheet, BQ294524DRVT pinout, BQ294524DRVT application, or BQ294524DRVT equivalent, key selection criteria include OVP threshold tolerance, delay time stability over temperature, low input leakage (<100 nA per cell), thermal pad grounding requirement, and compatibility with 2- or 3-cell stack configurations.

Technical Context

The BQ294524DRVT implements independent analog voltage sensing across three differential inputs (V1–VSS, V2–V1, V3–V2) using an internal multiplexer and precision reference. Its fixed 4.45 V overvoltage threshold is factory-programmed with ±10 mV accuracy at 25°C and drift of ±54 mV over –40°C to +110°C.

Upon detection of any cell exceeding VOV, a dedicated 6.5 s delay timer activates before asserting the open-drain OUT pin high. The device operates from 3 V to 25 V supply (VDD), supports Customer Test Mode (CTM) for accelerated validation, and requires PWRPAD connection to VSS for thermal and functional integrity.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ294524DRVT, BQ294522DRVT offers identical accuracy and package but reduces delay for faster intervention, while BQ294533DRVT maintains the same 6.5 s timing but raises OVP to 4.50 V-enabling tighter margin control in high-voltage cell stacks without changing board layout.

Availability

BQ294524DRVT is available at Aetrix Electronics and suitable for notebook computers, power tools, and portable instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for BQ294524DRVT 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 broad industrial and consumer market reach.

The BQ2945xy family is designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, delivering factory-trimmed precision, ultra-low power consumption, and robust thermal performance in compact WSON packages.

FAQ

What is the overvoltage protection threshold and delay time for BQ294524DRVT?

The BQ294524DRVT has a fixed overvoltage protection threshold of 4.45 V with ±10 mV accuracy at 25°C and a fixed delay time of 6.5 s (5.2–7.8 s over –40°C to +110°C). This configuration is factory-programmed and cannot be adjusted externally. The BQ294524DRVT uses this precise timing and voltage setting to provide reliable secondary protection in 2- or 3-series Li-ion battery applications.

How does the BQ294524DRVT interface with external FETs?

The BQ294524DRVT features an open-drain OUT pin that pulls high (to VDD level) when an overvoltage condition is confirmed after the 6.5 s delay. This signal directly drives the gate of an external N-channel MOSFET, enabling it to short the fuse to ground and initiate power cutoff. The BQ294524DRVT's OUT can sink ≥4.5 mA, eliminating need for external level-shifting or buffering circuits in standard implementations.

Is the thermal pad (PWRPAD) required for BQ294524DRVT operation?

Yes, the PWRPAD on the BQ294524DRVT must be electrically and thermally connected to the VSS net on the PCB. This connection is mandatory for proper functionality, thermal dissipation (RθJB = 110.7°C/W), and electrical stability. Leaving PWRPAD unconnected or floating will result in undefined behavior and potential failure to assert OUT correctly during overvoltage events. The BQ294524DRVT datasheet explicitly requires this bond for all operating conditions.

Can BQ294524DRVT be used in both 2-cell and 3-cell battery configurations?

Yes, the BQ294524DRVT supports both 2-series and 3-series Li-ion cell configurations. In a 2-cell setup, the V3 pin is shorted to V2; in a 3-cell setup, V1, V2, and V3 are connected to the respective cell positives. All three differential inputs (V1–VSS, V2–V1, V3–V2) are monitored independently, and the BQ294524DRVT asserts OUT if any one exceeds 4.45 V for 6.5 s. No configuration pins or external components are needed to switch between modes.

What is Customer Test Mode (CTM) and how is it activated on BQ294524DRVT?

Customer Test Mode (CTM) on the BQ294524DRVT reduces production test time by shortening the overvoltage delay from 6.5 s to ~15 ms. CTM is activated by applying VDD at least 10 V higher than the V3 pin voltage. The mode exits automatically when the VDD–V3 differential drops below 10 V. This feature allows rapid validation of OVP functionality without waiting for full delay timing, and is documented in the BQ294524DRVT datasheet Section 8.4.3.