Texas Instruments BQ771803DPJT

Overview

BQ771803DPJT 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) for long-term pack standby integrity in cordless power tools and e-bike battery management systems.

For engineers reviewing the BQ771803DPJT datasheet, BQ771803DPJT pinout, BQ771803DPJT application, or BQ771803DPJT equivalent, key selection criteria include its fixed 4.275 V overvoltage threshold, 50 mV 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 BQ771803DPJT implements independent per-cell voltage sensing across five differential inputs (V1–VSS to V5–V4), comparing each against a precision internal reference (VOV = 4.275 V). Upon detection of any cell exceeding VOV, a monolithic 1 s delay timer initiates before asserting the open-drain OUT pin low.

Its NCH open-drain output requires an external pull-up to PACK+ and supports fault signaling in battery packs where system-level disconnect logic responds to active-low signals. The device operates across –40°C to 110°C with supply voltage range 3 V to 25 V and input leakage <100 nA per sense pin - enabling high-impedance, low-error voltage monitoring without loading cells.

Key Specifications

Pinout & Package

Package: 8-pin WSON (QFN), 3.00 mm × 4.00 mm body size, wettable flank, 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 BQ771801DPJT and MP26123DJ-LF-Z, the BQ771803DPJT delivers optimal balance of speed (1 s delay), precision (±10 mV), and safety readiness - making it preferred for high-performance portable tools and mobility systems where rapid, deterministic overvoltage response is critical.

Availability

BQ771803DPJT is available at Aetrix Electronics and suitable for handheld power tools, e-scooter battery packs, and UPS backup systems requiring stable component supply, long-lifecycle support, and traceable sourcing for industrial OEM programs.

Supply support for BQ771803DPJT 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 expertise.

The BQ7718 family was designed specifically for cost-sensitive, high-reliability overvoltage protection in multi-cell Li-ion battery packs - prioritizing accuracy, ultra-low power, and functional safety readiness over integrated charging or communication features.

FAQ

What is the overvoltage protection threshold and accuracy of the BQ771803DPJT?

The BQ771803DPJT has a fixed overvoltage protection threshold of 4.275 V with ±10 mV accuracy at 25°C and ±54 mV maximum drift over –40°C to 110°C. This specification is measured per TI SLUSAX1L datasheet Section 7.5 and ensures reliable detection of Li-ion cell overcharge while maintaining safe voltage margins across operating temperature extremes. The BQ771803DPJT achieves this using a trimmed internal reference and matched comparator architecture.

Does the BQ771803DPJT support Customer Test Mode (CTM), and how is it activated?

Yes, the BQ771803DPJT supports Customer Test Mode to reduce production-line test time. CTM is activated by applying VDD at least 10 V higher than the V5 pin voltage - for example, if V5 = 16.5 V (4.275 V × 4 cells), then VDD ≥ 26.5 V triggers CTM. In this mode, the overvoltage delay reduces from 1 s to approximately 15 ms, enabling rapid functional verification without modifying PCB layout or firmware. The BQ771803DPJT exits CTM automatically when the VDD–V5 differential falls below 10 V.

What package type and footprint does the BQ771803DPJT use?

The BQ771803DPJT uses an 8-pin WSON (QFN) package designated DPJ, with nominal dimensions of 3.00 mm × 4.00 mm and wettable flanks for optical solder inspection. It is RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating (unlimited floor life at ≤30°C/60% RH). This package is pin-compatible with other BQ7718xy variants in DPJ format and requires standard QFN reflow profiles per JEDEC J-STD-020.

How does the BQ771803DPJT interface with external circuitry for fault signaling?

The BQ771803DPJT features an NCH open-drain active-low OUT pin that must be pulled up externally - typically to PACK+ via a 10–100 kΩ resistor - to generate a logic-high idle state and logic-low fault signal. When any monitored cell exceeds 4.275 V, the OUT pin sinks current to VSS after the 1 s delay, driving downstream logic (e.g., protection MOSFET gate or microcontroller interrupt) into fault state. The BQ771803DPJT specifies 0.5–14 mA sink capability and <100 nA leakage in inactive state.

Is the BQ771803DPJT suitable for functional safety–compliant battery systems?

Yes, the BQ771803DPJT is labeled "Functional Safety-Capable" by Texas Instruments, with supporting documentation including FIT rate calculations, failure mode analysis, and diagnostic coverage metrics to aid ISO 26262 ASIL-B or IEC 61508 SIL-2 system design. While the BQ771803DPJT itself is not certified, TI provides the necessary safety artifacts so system integrators can qualify the full battery pack. This capability is explicitly documented in the BQ771803DPJT datasheet Section 1 and Section 12.1.