Texas Instruments BQ29440DRBR

Overview

BQ29440DRBR from Texas Instruments is a second-level overvoltage protection IC for 2-, 3-, or 4-series Li-ion battery packs, featuring ±25 mV overvoltage detection accuracy (0°C to 60°C), 4.35 V fixed overvoltage threshold, and external capacitor-controlled delay timing. It operates with ICC < 2 µA typical supply current and delivers regulated OUT pin drive up to 9.5 V in overvoltage fault condition-used in notebook computers and power tools for cell-level voltage safety monitoring.

For engineers reviewing the BQ29440DRBR datasheet, BQ29440DRBR pinout, BQ29440DRBR application, or BQ29440DRBR equivalent, this page provides verified technical context, validated pin functions, confirmed 8-pin DRB QFN package mapping, real-world application roles, and two rigorously cross-checked alternative parts with documented functional and threshold differences.

Technical Context

The BQ29440DRBR implements independent per-cell voltage monitoring across up to four series-connected Li-ion cells using precision comparators referenced to an internal bandgap. Each VCx input (VC1–VC4) measures differential voltage between adjacent cell terminals, with overvoltage detection triggered when any single cell exceeds 4.35 V.

Upon detection, a 140 nA current source charges an external capacitor on the CD pin; when voltage reaches 1.2 V, the OUT pin transitions high (latched behavior is disabled in this variant). The device supports Customer Test Mode (CTM) with reduced delay scaling factor (0.08 s/µF) for accelerated production verification.

Key Specifications

Pinout & Package

Package: 8-pin SON (DRB), 3.0 mm × 3.0 mm body, 1.0 mm max height, thermally enhanced exposed pad requiring PCB solder connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29440DRBR, BQ29441DRBR raises the overvoltage trip point by 50 mV for wider cell voltage operating windows, while BQ29449DRBR lowers it by 50 mV to enforce stricter voltage clamping-both retain identical delay control, supply current, and thermal performance in the DRB package.

Availability

BQ29440DRBR is available at Aetrix Electronics and suitable for notebook computers, portable power tools, and industrial handheld scanners requiring stable component supply across extended product lifecycles.

Supply support for BQ29440DRBR 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, power conversion, and signal chain solutions.

The bq2944x family was designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, delivering precision voltage monitoring, programmable fault timing, and ultra-low-power operation for portable and industrial energy storage systems.

FAQ

What is the overvoltage protection threshold of the BQ29440DRBR?

The BQ29440DRBR has a fixed overvoltage protection (OVP) threshold of 4.35 V, specified with ±25 mV accuracy over 0°C to 60°C. This value is factory-trimmed and non-adjustable. The BQ29440DRBR does not support user-programmable thresholds - alternative variants like BQ29441DRBR (4.40 V) or BQ29449DRBR (4.30 V) offer different fixed thresholds within the same family and package.

Does the BQ29440DRBR provide latched or non-latched overvoltage output behavior?

The BQ29440DRBR implements non-latched overvoltage output behavior: the OUT pin transitions high during an overvoltage event and returns low once the fault condition clears and the CD capacitor fully discharges. Unlike the BQ2944L0 variant, the BQ29440DRBR lacks internal latch functionality - no external shorting of CD to GND is required to reset the output state.

How is the overvoltage delay time set on the BQ29440DRBR?

The overvoltage delay time on the BQ29440DRBR is set by an external capacitor connected to the CD pin. A 140 nA internal current source charges this capacitor; when voltage reaches 1.2 V, the OUT pin asserts. With a nominal scale factor of 9.0 s/µF, a 0.33 µF capacitor yields ~3 s delay. The BQ29440DRBR supports Customer Test Mode (CTM) for reduced delay scaling (0.08 s/µF) during production verification.

What package type and thermal characteristics does the BQ29440DRBR use?

The BQ29440DRBR uses an 8-pin SON (DRB) package measuring 3.0 mm × 3.0 mm with 1.0 mm max height and an exposed thermal pad. Its junction-to-ambient thermal resistance (qJA) is 50.5°C/W on a JEDEC-standard high-K board. The exposed pad must be soldered to the PCB for optimal thermal and mechanical performance, as specified in TI's SLUA271 layout guidelines.

Can the BQ29440DRBR monitor 2-series, 3-series, and 4-series Li-ion battery configurations?

Yes, the BQ29440DRBR supports 2-, 3-, and 4-series Li-ion battery configurations via its four dedicated voltage sense inputs (VC1–VC4). For 2-series use, only VC1, VC2, and GND are required; for 3-series, VC1–VC3 and GND; for 4-series, all VC1–VC4 plus GND. The BQ29440DRBR automatically adapts to the connected topology without configuration pins or firmware.