Texas Instruments BQ29442DRBR

Overview

BQ29442DRBR from Texas Instruments is a second-level overvoltage protection IC for 2-, 3-, or 4-series Li-ion battery packs, featuring 4.45 V fixed overvoltage threshold, ±25 mV accuracy (0°C to 60°C), <2 µA typical supply current, and external capacitor-controlled delay timing. It serves as critical secondary safety circuitry in portable power tools and notebook battery management systems.

For engineers reviewing the BQ29442DRBR datasheet, BQ29442DRBR pinout, BQ29442DRBR application, or BQ29442DRBR equivalent, key selection criteria include its precise 4.45 V OVP threshold, QFN-8 DRB package compatibility with thermal pad soldering, latch-free operation, and support for up to four-cell stack monitoring without external FETs.

Technical Context

The BQ29442DRBR implements independent per-cell voltage monitoring across VC1–VC4 inputs using high-accuracy comparators referenced to an internal bandgap. When any cell exceeds 4.45 V, a 140 nA current source charges the external CD capacitor until it reaches 1.2 V, triggering OUT high after a delay scalable by capacitor value (nominally 9.0 s/µF).

No internal latch is present-OUT returns low once overvoltage clears and the CD capacitor fully discharges via internal discharge block. The device operates from 4 V to 25 V supply, supports –40°C to +110°C ambient, and maintains ≤0.4 mV OVP accuracy drift over 0°C–60°C.

Key Specifications

Pinout & Package

Package: 8-pin SON (DRB), 3.0 mm × 3.0 mm, 0.5 mm pitch, exposed thermal pad (must be soldered to PCB ground plane for thermal and mechanical integrity).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29442DRBR, BQ29441DRBR offers a 50 mV lower OVP threshold for more conservative protection, while BQ29443DRBR provides a 50 mV higher threshold for extended charge acceptance - all share identical timing control, package, and temperature range.

Availability

BQ29442DRBR is available at Aetrix Electronics and suitable for power tools, notebook computers, and portable medical devices requiring stable component supply with guaranteed long-term sourcing.

Supply support for BQ29442DRBR 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 and ultra-low power are mandatory.

FAQ

What is the overvoltage protection threshold of the BQ29442DRBR?

The BQ29442DRBR has a fixed overvoltage protection (OVP) threshold of 4.45 V, with ±25 mV accuracy over 0°C to 60°C ambient temperature. This value is factory-trimmed and non-adjustable - it distinguishes BQ29442DRBR from other members of the bq2944x family such as BQ29441DRBR (4.40 V) and BQ29443DRBR (4.50 V). The BQ29442DRBR uses this precise threshold to trigger secondary protection in 2-, 3-, or 4-series Li-ion battery packs.

Does the BQ29442DRBR include an internal latch function?

No, the BQ29442DRBR does not include an internal latch. It is a non-latching variant - when an overvoltage condition clears, the internal discharge block resets the CD capacitor to 0 V, allowing the OUT pin to return low automatically. This behavior contrasts with latched versions like BQ2944L0DRBR. The BQ29442DRBR's unlatched operation enables automatic recovery without manual reset, making it suitable for applications requiring self-clearing fault responses.

How is the overvoltage delay time set on the BQ29442DRBR?

The overvoltage delay time on the BQ29442DRBR is set by an external capacitor connected to the CD pin (Pin 6). A nominal 140 nA internal current source charges this capacitor; when voltage reaches ~1.2 V, OUT transitions high. Delay = CCD × xDELAY, where xDELAY is nominally 9.0 s/µF (range 5.5–13.5 s/µF over –40°C to +110°C). For example, a 0.33 µF capacitor yields ~3 s nominal delay. The BQ29442DRBR does not require external resistors for timing - only the CD capacitor is needed.

What package type and thermal requirements apply to the BQ29442DRBR?

The BQ29442DRBR uses an 8-pin SON (DRB) package measuring 3.0 mm × 3.0 mm with 0.5 mm pitch and 1 mm maximum height. Its exposed thermal pad must be soldered to the PCB ground plane for both thermal dissipation and mechanical reliability - TI documentation explicitly states this is required, not optional. The BQ29442DRBR achieves 50.5°C/W junction-to-ambient thermal resistance on JEDEC-standard high-K board, and proper pad layout is essential for operation up to +110°C ambient.

Can the BQ29442DRBR monitor fewer than four cells?

Yes, the BQ29442DRBR supports 2-series and 3-series configurations in addition to 4-series. For 2-cell use, connect VC1 to top of stack, VC2 to midpoint, and GND to bottom; leave VC3 and VC4 unconnected (or tie VC3 to VC2 and VC4 to GND per TI guidance). For 3-cell, use VC1, VC2, VC3, and GND. All configurations retain full ±25 mV OVP accuracy and <2 µA ICC. The BQ29442DRBR's flexible input mapping eliminates need for external components when scaling across cell counts.