Texas Instruments BQ29443DRBR

Overview

BQ29443DRBR from Texas Instruments is a second-level overvoltage protection IC for 4-series Li-ion battery packs, featuring fixed 4.50 V per-cell overvoltage threshold, ±25 mV accuracy (0°C to 60°C), external capacitor-controlled delay timing, and low 2 µA typical supply current. It operates across –40°C to +110°C and drives an open-drain OUT pin to signal fault conditions in portable power tools and notebook battery management systems.

For engineers reviewing the BQ29443DRBR datasheet, BQ29443DRBR pinout, BQ29443DRBR application, or BQ29443DRBR equivalent, key selection criteria include its 4.50 V OVP threshold, DRB 8-pin QFN package with exposed thermal pad, programmable delay via CD pin capacitor, latch-free operation, and compatibility with 2–4 series cell configurations.

Technical Context

The BQ29443DRBR implements precision voltage monitoring across four independent cell inputs (VC1–VC4) using high-accuracy comparators referenced to an internal bandgap. Each cell voltage is compared against a fixed 4.50 V threshold with 200–400 mV hysteresis to prevent chatter during marginal overvoltage events.

Upon detection of any cell exceeding VPROTECT, a 140 nA current source charges an external capacitor on the CD pin; when the capacitor voltage reaches 1.2 V, the OUT pin transitions high after a delay scalable at 9.0 s/µF (nominal). The device lacks internal latching-OUT returns low once the overvoltage condition clears and the CD capacitor discharges.

Key Specifications

Pinout & Package

Package: DRB - 8-pin 3.0 mm × 3.0 mm SON (Small Outline No-Lead) with exposed thermal pad, RoHS-compliant, MSL Level-2-260°C-1 year.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29443DRBR, BQ29442DRBR offers a 50 mV lower trip point for conservative protection, while BD14000GUL integrates switching but sacrifices pin compatibility and multi-cell sensing granularity-making BQ29443DRBR optimal for drop-in 4-series upgrades requiring fixed 4.50 V precision.

Availability

BQ29443DRBR is available at Aetrix Electronics and suitable for power tools, notebook computers, and portable medical devices requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for BQ29443DRBR 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, precision, and energy efficiency.

The bq2944x family is designed specifically for secondary overvoltage protection in multi-cell Li-ion battery packs, targeting applications where hardware-based redundancy is mandated beyond primary charger control.

FAQ

What is the overvoltage protection threshold of the BQ29443DRBR?

The BQ29443DRBR has a fixed overvoltage protection threshold of 4.50 V per cell, specified with ±25 mV accuracy over 0°C to 60°C. This value is factory-trimmed and non-adjustable-unlike variants such as BQ29442DRBR (4.45 V) or BQ29449DRBR (4.30 V). The BQ29443DRBR uses this precise threshold to trigger secondary protection only when individual cell voltage exceeds safe operational limits, preventing thermal runaway in 2–4 series Li-ion configurations.

Does the BQ29443DRBR include internal latching functionality?

No, the BQ29443DRBR does not include internal latching. It is a non-latch variant-when an overvoltage condition clears, the internal current source disables and the CD capacitor discharges, causing the OUT pin to return to low. Latching is only available in the "L" suffix variants (e.g., BQ2944L3), which hold OUT high until CD is shorted to GND. The BQ29443DRBR's auto-reset behavior simplifies system recovery but requires continuous monitoring of cell voltage post-trip.

How is the overvoltage delay time set on the BQ29443DRBR?

The overvoltage delay time on the BQ29443DRBR is set by an external capacitor connected to the CD pin. A nominal 140 nA current charges the capacitor; when it reaches ~1.2 V, the OUT pin asserts. Delay = CCD × 9.0 s/µF (nominal), e.g., 0.33 µF yields ~3 s. The BQ29443DRBR supports Customer Test Mode (CTM), reducing delay scaling to 0.08 s/µF for accelerated production testing-activated by biasing VDD ≈ 9.5 V above VC1.

What package type and thermal characteristics does the BQ29443DRBR use?

The BQ29443DRBR uses the DRB package: an 8-pin 3.0 mm × 3.0 mm SON (Small Outline No-Lead) with exposed thermal pad. Its junction-to-ambient thermal resistance (θJA) is 50.5°C/W under JEDEC-standard conditions, and junction-to-board (θJB) is 19.3°C/W. The exposed pad must be soldered to a PCB copper pour for effective heat dissipation and mechanical stability-per TI's SLUA271 guidelines. This package enables high-density placement in space-constrained battery packs.

Can the BQ29443DRBR monitor fewer than four series cells?

Yes, the BQ29443DRBR supports 2-series and 3-series configurations in addition to 4-series. For 2-cell operation, connect VC1 to top of Cell 1, VC2 to node between cells, and GND to bottom of Cell 2; leave VC3 and VC4 unconnected (or tie VC3 to VC2, VC4 to GND per Figure 5). For 3-cell, use VC1–VC2–VC3–GND and leave VC4 floating. All configurations retain full 4.50 V per-cell OVP accuracy-the BQ29443DRBR adapts its sensing topology automatically based on connected VCx pins.