Texas Instruments BQ2944L0DRBT

Overview

BQ2944L0DRBT from Texas Instruments is a second-level overvoltage protection IC for 2-, 3-, or 4-series Li-ion battery packs, featuring latch-enabled OUT pin, 4.35 V fixed overvoltage threshold (±25 mV accuracy over 0°C–60°C), <2 µA typical supply current, and external capacitor-controlled delay timing. It operates across –40°C to +110°C and is used in notebook computers and power tools for cell-level voltage monitoring and fault isolation.

For engineers reviewing the BQ2944L0DRBT datasheet, BQ2944L0DRBT pinout, BQ2944L0DRBT application, or BQ2944L0DRBT equivalent, key selection criteria include latch behavior, 4.35 V OVP threshold tolerance, QFN-8 (DRB) package thermal performance, and compatibility with multi-cell stack topologies requiring secondary protection redundancy.

Technical Context

The BQ2944L0DRBT implements precision per-cell voltage monitoring using four independent VCx inputs (VC1–VC4) referenced to GND, comparing each against an internal 4.35 V reference with ±25 mV accuracy at 0°C–60°C. Its latch function holds the OUT pin high indefinitely after overvoltage detection until CD is shorted to GND.

Delay timing is set by an external capacitor on CD pin, charged by a 140 nA current source; transition occurs when CD reaches ~1.2 V. The device supports Customer Test Mode (CTM), reducing delay scale factor from 9.0 s/µF to 0.08 s/µF for accelerated production testing.

Key Specifications

Pinout & Package

Package: 8-pin SON (DRB), 3.0 mm × 3.0 mm, 0.5 mm pitch, exposed thermal pad - requires soldering to PCB thermal plane for reliability and thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ2944L0DRBT, BQ29440DRBT lacks latch persistence and requires external reset handling, while BQ2944L9DRBT provides identical latch functionality but at a lower 4.30 V threshold-making it suitable for different cell voltage profiles but not a drop-in replacement without revalidation.

Availability

BQ2944L0DRBT is available at Aetrix Electronics and suitable for notebook computers, power tools, and portable medical devices requiring stable component supply and long-term lifecycle support.

Supply support for BQ2944L0DRBT 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 solutions.

The bq2944x family is designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, targeting applications where redundancy, latch behavior, and precision voltage thresholds are critical for safety compliance.

FAQ

What is the overvoltage protection threshold of the BQ2944L0DRBT?

The BQ2944L0DRBT has a fixed overvoltage protection threshold of 4.35 V per cell, with ±25 mV accuracy over 0°C to 60°C. This value is factory-trimmed and non-adjustable. The BQ2944L0DRBT uses this threshold to detect overvoltage conditions across any monitored cell in 2-, 3-, or 4-series configurations, triggering its latch-enabled output after the programmed delay.

Does the BQ2944L0DRBT support latch functionality?

Yes, the BQ2944L0DRBT includes a latch function: once an overvoltage condition is detected and the delay timer expires, the OUT pin transitions high and remains latched in that state until the CD pin is shorted to GND. This behavior distinguishes the BQ2944L0DRBT from non-latch variants like BQ29440DRBT and ensures persistent fault signaling without external supervision.

How is the overvoltage delay time set on the BQ2944L0DRBT?

The overvoltage delay time on the BQ2944L0DRBT is set by an external capacitor connected to the CD pin. A nominal 140 nA current charges the capacitor; when voltage reaches ~1.2 V, the OUT pin asserts. With a 9.0 s/µF scale factor, a 0.33 µF capacitor yields ~3 s delay. The BQ2944L0DRBT supports Customer Test Mode (CTM), reducing the scale factor to 0.08 s/µF for accelerated validation.

What package type does the BQ2944L0DRBT use, and what are its thermal requirements?

The BQ2944L0DRBT uses an 8-pin SON (DRB) package measuring 3.0 mm × 3.0 mm with 0.5 mm pitch and an exposed thermal pad. Per TI documentation, the thermal pad must be soldered to a PCB copper plane for mechanical stability and thermal performance. Junction-to-board thermal resistance is 19.3°C/W, confirming the need for adequate board-level copper area under the pad.

Can the BQ2944L0DRBT monitor 2-cell, 3-cell, and 4-cell Li-ion battery configurations?

Yes, the BQ2944L0DRBT supports 2-, 3-, and 4-series Li-ion battery configurations via its VC1–VC4 inputs and GND reference. For 2-cell stacks, only VC1, VC2, and GND are used; for 4-cell, all four VCx pins plus GND are connected in descending stack order. The BQ2944L0DRBT's architecture ensures accurate per-cell voltage comparison regardless of series count, making it adaptable across multiple pack topologies.