Texas Instruments BQ771815DPJT

Overview

BQ771815DPJT 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 monitors each cell independently and delivers ultra-low quiescent current (≈1 µA) and sub-100 nA per-cell leakage for long-term pack standby integrity in cordless power tools and e-bike battery management systems.

For engineers reviewing the BQ771815DPJT datasheet, BQ771815DPJT pinout, BQ771815DPJT application, or BQ771815DPJT 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 high-reliability portable energy storage designs.

Technical Context

The BQ771815DPJT implements independent differential voltage sensing across five cell inputs (V1–V5 relative to VSS), comparing each against a precision internal reference to trigger an overvoltage event. Its internal delay timer initiates upon first cell OVP detection and expires after exactly 1 s (typical), at which point the OUT pin actively pulls low.

This device operates in NORMAL mode when all cell voltages remain below 4.225 V and transitions to OVERVOLTAGE mode only when any single cell exceeds that threshold by more than hysteresis (50 mV). The NCH open-drain output requires an external pull-up resistor to PACK+ and supports Customer Test Mode (CTM) with 15 ms fault detection for production-line validation.

Key Specifications

Pinout & Package

Package: 8-pin WSON (QFN), 3.00 mm × 4.00 mm, wettable flank, RoHS-compliant, moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ771815DPJT, BQ771802DPJT offers identical electrical behavior and mechanical fit, whereas MP2672GQ-Z introduces higher integration at the cost of increased complexity, larger footprint, and non-interchangeable pinout - making BQ771815DPJT optimal for discrete, low-power, space-constrained OVP-only implementations.

Availability

BQ771815DPJT 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-lifecycle support, and functional safety documentation.

Supply support for BQ771815DPJT 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 specializing in analog, embedded processing, and power management technologies with decades of battery management system expertise.

The BQ7718 family was designed specifically for high-accuracy, low-power, hardware-based overvoltage protection in multi-cell Li-ion battery packs used in portable industrial and consumer energy storage applications.

FAQ

What is the overvoltage protection threshold and accuracy of the BQ771815DPJT?

The BQ771815DPJT has a fixed overvoltage protection threshold of 4.225 V with ±10 mV accuracy at 25°C and ±54 mV maximum drift over –40°C to +110°C. This specification is guaranteed across temperature and supply voltage (3–25 V), enabling reliable cell-level voltage clamping without calibration in production.

Does the BQ771815DPJT require external timing components for its overvoltage delay?

No, the BQ771815DPJT integrates a fixed 1 s (typical) internal delay timer - no external capacitors or resistors are needed. This eliminates component count, layout sensitivity, and parametric variation, ensuring consistent OVP response time across units and environmental conditions.

How is the output configured on the BQ771815DPJT, and what external circuitry is required?

The BQ771815DPJT features an NCH open-drain active-low output (OUT pin). An external pull-up resistor to PACK+ is mandatory to establish a defined logic-high state when no fault is present. Typical values range from 10 kΩ to 100 kΩ depending on rise-time and noise immunity requirements.

Can the BQ771815DPJT monitor fewer than five cells, such as in a 2S or 3S battery pack?

Yes, the BQ771815DPJT supports 2-, 3-, 4-, and 5-series configurations. Unused sense inputs (e.g., V4 and V5 in a 2S pack) must be tied to appropriate potentials per TI's layout guidelines - typically VSS or adjacent cell terminals - to avoid floating nodes and ensure stable operation.

Is functional safety documentation available for the BQ771815DPJT?

Yes, Texas Instruments provides functional safety documentation for the BQ771815DPJT to aid system-level ISO 26262 and IEC 61508 compliance. This includes FMEDA reports, diagnostic coverage analysis, and safety manual guidance - all accessible through TI's official BQ7718 product folder.