Texas Instruments BQ771809DPJR

Overview

BQ771809DPJR 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 only ≈1 µA in normal state, enabling reliable cell-level voltage monitoring in portable power tools and e-bike battery management systems.

For engineers reviewing the BQ771809DPJR datasheet, BQ771809DPJR pinout, BQ771809DPJR application, or BQ771809DPJR equivalent, key selection criteria include its 4.200 V OVP threshold with 50 mV hysteresis, 1 s fault delay timing, QFN-8 (3.00 mm × 4.00 mm) package, functional safety documentation support, and compatibility with 2–5 cell stack topologies requiring low-leakage (<100 nA per cell) sensing.

Technical Context

The BQ771809DPJR 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.

Its sensing architecture requires external RC filters on each Vx input and supports Customer Test Mode (CTM) with sub-15 ms fault detection for production-line validation. The device draws <1 µA supply current when all cells are below threshold and maintains <100 nA leakage per sense input.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ771809DPJR, BQ771808DPJR offers identical protection timing but requires external biasing for logic-level compatibility, while BQ771811DPJR raises the trip point by 25 mV to improve robustness in thermally stressed or high-impedance pack configurations.

Availability

BQ771809DPJR is available at Aetrix Electronics and suitable for handheld power tools, cordless vacuum cleaners, and light electric vehicle battery packs requiring stable component supply, long-term lifecycle support, and functional safety documentation.

Supply support for BQ771809DPJR 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 deep expertise in battery management solutions.

The BQ7718 family is designed specifically for standalone overvoltage protection in multi-cell Li-ion battery packs, emphasizing precision, ultra-low power, and functional safety readiness without requiring microcontroller intervention.

FAQ

What is the overvoltage protection threshold and accuracy of the BQ771809DPJR?

The BQ771809DPJR has a fixed overvoltage protection threshold of 4.200 V with ±10 mV accuracy at 25°C and ±54 mV maximum drift across –40°C to 110°C. This specification ensures reliable cell-level voltage clamping for 2- to 5-series Li-ion battery packs without external calibration or trimming, supporting safe operation in demanding portable power applications where precise voltage limits are critical.

How does the BQ771809DPJR handle multiple cell monitoring and what is its input leakage current?

The BQ771809DPJR independently monitors up to five differential cell voltages (V1–VSS through V5–V4) using dedicated sense inputs. Each input exhibits less than 100 nA leakage current, preserving inter-cell voltage balance during long idle periods and minimizing impact on pack self-discharge rate. This low-leakage design reduces passive balancing requirements and extends battery shelf life in applications like UPS and e-bike storage.

What output configuration does the BQ771809DPJR use and how is it driven?

The BQ771809DPJR features a CMOS active-high output (OUT pin) that drives high (≥6 V at 100 µA load) upon overvoltage detection after the 1 s delay timer expires. Unlike open-drain variants, it requires no external pull-up resistor and interfaces directly with logic-level inputs of gate drivers or microcontrollers, simplifying PCB layout and reducing bill-of-materials count in space-constrained battery pack designs.

Does the BQ771809DPJR support functional safety standards and what documentation is available?

Yes, the BQ771809DPJR is functional safety-capable, with TI providing documentation to aid ISO 26262 ASIL-B or IEC 61508 SIL-2 system-level safety analysis. This includes failure mode, effects, and diagnostic analysis (FMEDA) data and safety manual guidance-enabling integration into automotive, industrial, and medical battery systems where hardware-level fault detection must meet rigorous safety integrity requirements.

What package type and thermal characteristics apply to the BQ771809DPJR?

The BQ771809DPJR is packaged in an 8-pin WSON (DPJ) format measuring 3.00 mm × 4.00 mm with wettable flanks. Its junction-to-ambient thermal resistance is 56.6°C/W, and it supports continuous operation from –40°C to 110°C ambient. The small footprint and robust thermal performance make it suitable for densely populated battery pack PCBs in handheld tools and e-mobility applications where space and reliability are critical.