Texas Instruments BQ771815DPJR

Overview

BQ771815DPJR 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 NCH open-drain active-low output. It independently monitors each cell voltage with <100 nA input leakage and draws ≈1 µA supply current below protection threshold-enabling reliable safety-critical cutoff in cordless power tools and e-bike battery management systems.

For engineers reviewing the BQ771815DPJR datasheet, BQ771815DPJR pinout, BQ771815DPJR application, or BQ771815DPJR equivalent, key selection criteria include its fixed 4.225 V overvoltage threshold, 50 mV hysteresis, QFN-8 (3.0 × 4.0 mm) package, functional safety documentation support, and compatibility with external pull-up configurations for fault signaling in multi-cell pack designs.

Technical Context

The BQ771815DPJR implements independent per-cell voltage sensing across five differential inputs (V1–V5 relative to VSS), 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 open-drain OUT pin low.

Its NCH active-low output requires an external pull-up resistor to PACK+ or system rail; during overvoltage, OUT sinks up to 14 mA while maintaining <400 mV saturation voltage at 100 µA load. The device operates from 3 V to 25 V supply (VDD–VSS) and supports –40°C to 110°C ambient temperature.

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 BQ771802DPJR and BQ771803DPJR, the BQ771815DPJR uniquely balances tight 50 mV hysteresis for responsive recovery with industry-standard 4.225 V threshold-making it optimal for mainstream 18650/21700-based power tools and e-mobility packs where both precision and noise immunity are required.

Availability

BQ771815DPJR is available at Aetrix Electronics and suitable for handheld power tools, cordless vacuum cleaners, and light electric vehicle battery packs requiring stable component supply, functional safety documentation, and long-term lifecycle support.

Supply support for BQ771815DPJR 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 and embedded processing solutions for industrial, automotive, and personal electronics markets.

The BQ7718 family is designed specifically for standalone, high-accuracy overvoltage protection in multi-cell Li-ion battery packs-prioritizing precision, ultra-low power, and functional safety readiness over programmability or communication interfaces.

FAQ

What is the overvoltage protection threshold and accuracy of the BQ771815DPJR?

The BQ771815DPJR has a fixed overvoltage protection threshold of 4.225 V with ±10 mV accuracy at 25°C and ≤54 mV total drift across –40°C to 110°C. This specification ensures reliable cell-level shutdown before lithium plating or electrolyte breakdown occurs, directly supporting UL 1642 and IEC 62133 compliance in certified battery packs. The BQ771815DPJR achieves this via trimmed internal reference and matched comparator design.

Does the BQ771815DPJR require external components for basic operation?

Yes-the BQ771815DPJR requires external RC filters on all Vx sense pins (RIN = 1 kΩ, CIN = 0.1 µF typical) and on VDD (RVD/CVD) for noise immunity and stability. An external pull-up resistor on the OUT pin is mandatory for its NCH open-drain active-low configuration. These components are specified in TI's BQ771815DPJR datasheet Section 9.1 and Figure 9-1, and omission compromises OVP accuracy and EMI resilience.

How does the Customer Test Mode (CTM) function in the BQ771815DPJR?

The BQ771815DPJR enters Customer Test Mode when VDD exceeds V5 by ≥10 V, reducing the overvoltage delay from 1 s to ~15 ms. This enables rapid functional verification during battery pack manufacturing without waiting for full delay timing. CTM exits automatically when the VDD–V5 differential drops below 10 V. The BQ771815DPJR datasheet cautions against exceeding absolute maximum ratings during CTM entry.

What package type and mounting considerations apply to the BQ771815DPJR?

The BQ771815DPJR uses an 8-pin WSON (DPJ) package measuring 3.00 mm × 4.00 mm with wettable flanks for automated optical inspection. Layout requires short, direct traces from V1/VSS and VDD to their respective cell terminals, placement of RC filters adjacent to pins, and grounding VSS exclusively to the bottom cell's negative terminal-not system ground. Thermal resistance is 56.6°C/W junction-to-ambient (RθJA).

Is the BQ771815DPJR suitable for functional safety–certified battery systems?

Yes-the BQ771815DPJR is labeled "Functional Safety-Capable" with documentation available to aid ISO 26262 ASIL-B or IEC 61508 SIL-2 system-level safety analysis, including failure modes, diagnostic coverage estimates, and FIT rate data. While the BQ771815DPJR itself is not pre-certified, its design and supporting collateral enable integration into certified BMS architectures when used per TI's safety manual guidelines.