Texas Instruments BQ771809DPJT

Overview

BQ771809DPJT from Texas Instruments is a dedicated overvoltage protection IC for 2- to 5-series Li-ion battery packs, featuring ±10 mV OVP accuracy, 4.200 V fixed overvoltage threshold, 1 s internal delay timer, and CMOS active-high output drive. It operates across –40°C to 110°C and consumes ≈1 µA in normal state, enabling reliable cell-level fault detection in cordless power tools and e-bike battery management systems.

For engineers reviewing the BQ771809DPJT datasheet, BQ771809DPJT pinout, BQ771809DPJT application, or BQ771809DPJT equivalent, key selection criteria include its 4.200 V OVP threshold with 50 mV hysteresis, 1 s delay timing, QFN-8 (3.00 mm × 4.00 mm) package, functional safety documentation support, and compatibility with 2–5 cell stack topologies.

Technical Context

The BQ771809DPJT independently monitors up to five differential cell voltages (V1–VSS through V5–V4) using precision internal references. Upon detecting any cell exceeding 4.200 V, it initiates a fixed 1 s delay timer before asserting the CMOS active-high OUT signal.

This device integrates no external timing components-delay is fully internal-and supports Customer Test Mode (CTM) with sub-15 ms fault detection for production-line validation. Its low 100 nA per-cell input leakage and 1 µA supply current enable minimal impact on pack self-discharge.

Key Specifications

Pinout & Package

Package: 8-pin WSON (DPJ), 3.00 mm × 4.00 mm body, wettable flank, RoHS-compliant, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ771809DPJT, BQ771808DPJT offers identical protection thresholds but requires external biasing for logic-level compatibility, while BQ771811DPJT raises the OVP point by 25 mV to improve robustness against voltage transients in thermally stressed packs-both retain the same QFN-8 footprint and functional safety documentation support.

Availability

BQ771809DPJT is available at Aetrix Electronics and suitable for handheld power tools, cordless vacuum cleaners, and light electric vehicles requiring stable component supply, long-term lifecycle assurance, and functional safety documentation support.

Supply support for BQ771809DPJT 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, embedded processing, and power management technologies, with leadership in battery management solutions for industrial and consumer applications.

The BQ7718 family is designed specifically for standalone overvoltage protection in multi-cell Li-ion battery packs, targeting cost-sensitive, high-reliability applications where simplicity, low power, and functional safety readiness are essential.

FAQ

What is the overvoltage protection threshold and accuracy of the BQ771809DPJT?

The BQ771809DPJT has a fixed overvoltage protection (OVP) threshold of 4.200 V with ±10 mV accuracy at 25°C, and maintains ±54 mV accuracy across the full –40°C to 110°C operating range. This precision enables reliable cell-level protection without trimming or calibration, and the 50 mV hysteresis prevents chatter during voltage recovery. The BQ771809DPJT achieves this using factory-trimmed internal references and matched comparator circuitry.

Does the BQ771809DPJT require external timing components for its overvoltage delay?

No, the BQ771809DPJT features a fully internal 1 s delay timer-no external capacitor or resistor is needed. This simplifies PCB layout, reduces bill-of-materials cost, and improves timing consistency across temperature and unit-to-unit variation. The BQ771809DPJT also supports Customer Test Mode (CTM), which reduces the effective delay to under 15 ms for production-line functional testing without modifying hardware.

How does the BQ771809DPJT interface with a microcontroller or protection FET driver?

The BQ771809DPJT provides a CMOS active-high output on the OUT pin, capable of sourcing up to 4.5 mA at VDD = 18 V. It drives logic-high directly without external pull-up resistors and interfaces seamlessly with standard 3.3 V or 5 V MCU GPIOs or discrete MOSFET gate drivers. The BQ771809DPJT's rail-to-rail output swing ensures robust noise margin in noisy battery-pack environments.

What package type and mounting features does the BQ771809DPJT use?

The BQ771809DPJT is supplied in an 8-pin WSON (DPJ) package measuring 3.00 mm × 4.00 mm with wettable flanks for automated optical inspection (AOI) of solder joints. It uses a single-row, no-lead design with exposed thermal pad, rated MSL Level-1, and supports standard reflow profiles. The BQ771809DPJT's compact footprint and thermal performance make it ideal for space-constrained battery pack PCBs.

Is functional safety documentation available for the BQ771809DPJT?

Yes, Texas Instruments provides functional safety documentation for the BQ771809DPJT, including FMEDA reports, safety analysis summaries, and diagnostic coverage data to support ISO 26262 ASIL-B system-level development. This documentation is publicly accessible via TI's product folder and is included in the BQ7718 technical documentation suite. The BQ771809DPJT itself is classified as "Functional Safety-Capable" per TI's safety program.