Texas Instruments BQ771811DPJT

Overview

BQ771811DPJT from Texas Instruments is a dedicated overvoltage protection IC for 2- to 5-series Li-ion battery packs, featuring ±10 mV OVP accuracy, 1 s internal delay timer, and CMOS active-high output drive. It monitors each cell independently and delivers ultra-low quiescent current (≈1 µA) for long-term pack standby integrity in cordless power tools and e-bike battery management systems.

For engineers reviewing the BQ771811DPJT datasheet, BQ771811DPJT pinout, BQ771811DPJT application, or BQ771811DPJT equivalent, key selection criteria include its fixed 4.225 V overvoltage threshold, 0.05 V hysteresis, 8-pin QFN (3.00 mm × 4.00 mm) package, functional safety documentation support, and compatibility with Customer Test Mode for accelerated production-line validation.

Technical Context

The BQ771811DPJT implements independent per-cell voltage sensing across five differential inputs (V1–VSS to V5–V4), comparing each against a precision internal reference (VOV = 4.225 V). Upon detection of any cell exceeding VOV, a fixed 1 s delay timer initiates before asserting the CMOS active-high OUT signal.

Its architecture integrates low-leakage input circuitry (<100 nA per cell), unregulated VDD operation (3–25 V), and thermal robustness (–40°C to 110°C operating range). The device supports Customer Test Mode (CTM) with sub-15 ms fault detection delay for factory testing without compromising normal-mode timing fidelity.

Key Specifications

Pinout & Package

Package: 8-pin WSON (QFN), 3.00 mm × 4.00 mm body, wettable flanks, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ771811DPJT, BQ771802DPJT offers identical protection thresholds but different output polarity for system-level fault bus design, while BQ771818DPJT trades tighter hysteresis and higher trip point for broader chemistry compatibility-neither is pin-compatible, but both share identical QFN-8 footprint and layout rules.

Availability

BQ771811DPJT is available at Aetrix Electronics and suitable for handheld power tools, e-bike battery packs, and cordless vacuum cleaner designs requiring stable component supply, long-term lifecycle assurance, and functional safety documentation support.

Supply support for BQ771811DPJT 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 industrial interface solutions.

The BQ7718 family is designed specifically for cost-sensitive, high-reliability overvoltage protection in multi-cell Li-ion battery packs used in portable power equipment and light electric vehicles.

FAQ

What is the exact overvoltage protection threshold and accuracy of the BQ771811DPJT?

The BQ771811DPJT has a fixed overvoltage protection threshold of 4.225 V with ±10 mV accuracy at 25°C, and maintains ±44 mV accuracy across the full –40°C to 110°C operating temperature range. This specification is measured under defined conditions (VDD = 18 V, TA = –40°C to 110°C) and applies to all five cell inputs (V1–VSS through V5–V4) independently. The BQ771811DPJT uses an internal trimmed reference to achieve this precision without external calibration components.

Does the BQ771811DPJT support Customer Test Mode, and how is it activated?

Yes, the BQ771811DPJT supports Customer Test Mode (CTM) to reduce production-line OVP validation time. CTM is activated by applying a VDD voltage at least 10 V higher than the V5 pin voltage, which triggers a shortened fault detection delay of ≤15 ms. The BQ771811DPJT exits CTM automatically when the VDD-to-V5 differential falls below 10 V. This mode is fully documented in the official datasheet Section 8.4.3 and requires no additional pins or configuration.

What package type and footprint does the BQ771811DPJT use, and is it RoHS-compliant?

The BQ771811DPJT uses an 8-pin WSON (QFN) package with a 3.00 mm × 4.00 mm body size, wettable flanks, and NiPdAu lead finish. It is RoHS-compliant, rated MSL Level-1 (unlimited floor life at ≤30°C/60% RH), and compatible with standard reflow profiles up to 260°C peak. The BQ771811DPJT shares the same footprint as other DPJ-orderable variants in the BQ7718xy family, enabling layout reuse across voltage-threshold options.

How does the BQ771811DPJT handle cell voltage sensing and what external components are required?

The BQ771811DPJT senses each cell differentially using five dedicated inputs (V1–VSS to V5–V4), requiring a 1 kΩ resistor (RIN) and 0.1 µF capacitor (CIN) per input for noise filtering and stable measurement. The device is calibrated for RIN = 1 kΩ; deviation affects OVP accuracy. A separate RC filter (RVD/CVD) is required on VDD. All external components must be placed close to respective pins per layout guidelines in the BQ771811DPJT datasheet.

Is the BQ771811DPJT functional safety-certified, and what documentation is available?

The BQ771811DPJT is functional safety-capable, with TI providing supporting documentation-including FIT rate data, failure mode effects analysis (FMEA), and diagnostic coverage metrics-to aid system-level ISO 26262 ASIL-B or IEC 61508 SIL-2 certification. This documentation is accessible via TI's product folder and is specific to the BQ771811DPJT device; no additional hardware modifications are needed to leverage these resources in safety-critical battery pack designs.