Texas Instruments BQ294533DRVR

Overview

BQ294533DRVR from Texas Instruments is a secondary overvoltage protection IC for 3-series Li-ion battery packs, featuring a fixed 4.5 V OVP threshold, 6.5 s fault detection delay, ±10 mV accuracy, 1 µA supply current (VCELL < VPROTECT), and 6-pin SON package. It independently monitors each cell and drives an external N-channel FET to trigger fuse blow during overvoltage events in portable power tools and notebooks.

For engineers reviewing the BQ294533DRVR datasheet, BQ294533DRVR pinout, BQ294533DRVR application, or BQ294533DRVR equivalent, key selection criteria include confirmed 3-cell support, fixed 4.5 V / 6.5 s configuration, thermal pad grounding requirement, low-leakage (<100 nA per cell) sensing inputs, and compatibility with NMOS-based secondary protection circuits.

Technical Context

The BQ294533DRVR implements independent analog voltage monitoring across three differential cell inputs (V1–VSS, V2–V1, V3–V2) using internal precision comparators referenced to a factory-trimmed 4.5 V OVP threshold. Its fixed 6.5 s delay timer activates only upon sustained overvoltage exceeding VOV minus 300 mV hysteresis.

Output logic is open-drain compatible with external NMOS gate drive; OUT transitions high after delay expiration to enable fuse-blow path. The device operates from 3 V to 25 V supply (VDD), supports –40°C to +110°C ambient, and requires PCB-level PWRPAD-to-VSS connection 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) that must be connected to VSS on PCB for proper operation and thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ294533DRVR, BQ294532DRVR offers faster response at identical voltage threshold, while BQ294524DRVR provides earlier intervention at reduced voltage-both retain identical pinout, leakage, and thermal characteristics for drop-in layout reuse.

Availability

BQ294533DRVR is available at Aetrix Electronics and suitable for power tools, notebook computers, and portable instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed second-source availability for safety-critical battery protection.

Supply support for BQ294533DRVR 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 leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in battery management solutions.

The BQ2945xy family is designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, delivering factory-trimmed accuracy, ultra-low power consumption, and robust operation across industrial temperature ranges.

FAQ

What is the exact overvoltage protection threshold and tolerance for BQ294533DRVR?

The BQ294533DRVR has a factory-programmed overvoltage protection threshold of 4.5 V with ±10 mV accuracy at 25°C. This specification is guaranteed across –40°C to +110°C ambient temperature, with additional drift of ±54 mV at temperature extremes. The BQ294533DRVR uses this fixed threshold to trigger protection independently on any of the three monitored cells.

Does BQ294533DRVR support both 2-cell and 3-cell Li-ion configurations?

Yes, BQ294533DRVR supports both 2-series and 3-series Li-ion battery configurations. In 2-cell mode, the V3 pin is shorted to V2; in 3-cell mode, all three sense inputs (V1, V2, V3) are used independently. The BQ294533DRVR maintains identical OVP threshold and delay timing regardless of configuration, with no external programming required.

How is the thermal pad (PWRPAD) used in BQ294533DRVR layout?

The PWRPAD on BQ294533DRVR must be electrically and thermally connected to the VSS net on the PCB-this is mandatory for correct operation and thermal performance. Failure to connect PWRPAD to VSS may result in unstable output behavior or premature thermal shutdown. The BQ294533DRVR datasheet specifies this as a functional requirement, not just a recommendation.

What is the purpose of Customer Test Mode (CTM) in BQ294533DRVR?

Customer Test Mode (CTM) in BQ294533DRVR reduces production test time by shortening the overvoltage delay from 6.5 s to 15 ms when VDD exceeds V3 by ≥10 V. This allows rapid verification of the protection circuit without waiting for full delay timeout. CTM exits automatically when the VDD–V3 differential drops below 10 V, and the BQ294533DRVR resumes normal operation.

Can BQ294533DRVR drive an external MOSFET directly, and what are the output specifications?

Yes, BQ294533DRVR drives external N-channel MOSFET gates directly via its OUT pin. The output delivers ≥6 V at 100 µA load when VDD = 7.2 V and pulls low to ≤400 mV under same conditions. Output impedance is 2–5 kΩ, and short-circuit current capability is 4.5 mA-sufficient to rapidly charge/discharge typical NMOS gate capacitance in fuse-blow circuits.