Texas Instruments BQ7721605PWR

Overview

BQ7721605PWR from Texas Instruments is a fixed-threshold, 16-cell Li-ion battery voltage and temperature protection IC with integrated delay timers. It provides independent per-cell overvoltage (4.225 V ±20 mV), undervoltage (2.6 V ±50 mV), open-wire, and overtemperature (75°C) detection, driving active-high COUT/DOUT outputs to control external FETs or fuses in cordless power tool battery packs.

For engineers reviewing the BQ7721605PWR datasheet, BQ7721605PWR pinout, BQ7721605PWR application, or BQ7721605PWR equivalent, this page delivers verified specifications, TSSOP-24 package mapping, functional safety-capable architecture, and real-world implementation context for production-grade Li-ion pack design.

Technical Context

The BQ7721605PWR implements independent analog voltage comparators per cell input (V1–V16), ratiometric NTC-based temperature sensing via TS pin with internal 20 kΩ pullup, and fixed internal delay timers (1 s OVP/UVP, 4 s OT/OW) that trigger fault outputs only after timeout-preventing transient false trips. Its oscillator health monitor detects clock slowdown to ensure timing integrity.

It operates across –40°C to 110°C junction temperature, accepts unregulated VDD up to 75 V (stack top voltage), and features low quiescent current (≈3.5 µA) with <100 nA per-cell leakage when open-wire detection is disabled-enabling long-term battery standby without significant self-discharge.

Key Specifications

Pinout & Package

Package: 24-pin TSSOP (PW), body size 4.40 mm × 7.80 mm, 0.65 mm lead pitch, leaded surface-mount format compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Li-ion battery protection applications.

Compared with BQ7721605PWR, BQ7721606PWR raises overvoltage protection by 50 mV for higher-energy-density cells, while BQ7721615PWR extends overtemperature threshold to 83°C-both retain identical TSSOP-24 packaging, active-high output drive, and 1 s/4 s delay architecture, enabling drop-in evaluation with only OTP configuration updates.

Availability

BQ7721605PWR is available at Aetrix Electronics and suitable for handheld power tools, cordless vacuum cleaners, eBike battery packs, and UPS backup systems requiring stable component supply, long-lifecycle assurance, and automotive-grade reliability under thermal stress.

Supply support for BQ7721605PWR 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 expertise in battery management systems for industrial and consumer applications.

The BQ77216xx product line was designed specifically for cost-sensitive, high-volume Li-ion battery packs in cordless power equipment-delivering fixed-threshold protection with minimal external components and robust thermal fault coverage.

FAQ

What is the overvoltage protection threshold and accuracy of the BQ7721605PWR?

The BQ7721605PWR has a factory-programmed overvoltage protection threshold of 4.225 V with ±10 mV accuracy at 25°C and ±20 mV accuracy from 0°C to 60°C. This precision enables reliable cell balancing and prevents premature cutoff in high-performance 16S Li-ion packs used in professional power tools. The BQ7721605PWR achieves this via laser-trimmed internal references and matched comparator architectures.

Does the BQ7721605PWR support open-wire detection, and how does it affect leakage current?

The BQ7721605PWR has open-wire detection disabled by default, resulting in <100 nA per-cell input leakage current-critical for minimizing self-discharge in long-storage applications like UPS backup batteries. When enabled, leakage increases to ≤300 nA per input. The BQ7721605PWR's open-wire function applies a 50 µA pulsed sink every 128 ms to detect disconnected cells without compromising standby efficiency.

How does the Customer Test Mode (CTM) function in the BQ7721605PWR?

The BQ7721605PWR enters Customer Test Mode when VDD exceeds V16 by ≥12 V, reducing all fault delay timers to 50 ms-enabling rapid production-line verification of protection timing without full thermal or voltage stress testing. CTM exits automatically when the VDD–V16 differential drops below 10 V. The BQ7721605PWR maintains full functional safety monitoring during CTM, including oscillator health checks.

What is the temperature sensing configuration for the BQ7721605PWR?

The BQ7721605PWR uses its TS pin with an internal 20 kΩ pullup resistor to read an external NTC thermistor connected between TS and VSS. It detects overtemperature at 75°C ±5°C by measuring the resulting voltage divider ratio. The BQ7721605PWR requires ≤200 pF total capacitance on the TS pin to maintain measurement accuracy and does not support external capacitors for filtering.

Can the BQ7721605PWR drive external MOSFET gates directly?

Yes-the BQ7721605PWR's COUT and DOUT pins provide active-high 6 V drive capability with 4.5 mA source current, sufficient to directly switch logic-level N-channel MOSFET gates in typical battery disconnect circuits. The BQ7721605PWR also supports open-drain configurations via external pullups, offering flexibility for legacy designs using active-low control signals.