Texas Instruments BQ294702DSGT

Overview

BQ294702DSGT from Texas Instruments is a dedicated 4-series Li-ion battery overvoltage protection IC with factory-programmed 4.300 V OVP threshold, ±10 mV accuracy, external capacitor-programmed delay timer (1–2 s), and CMOS active-high output drive. It monitors each cell independently and triggers fault response upon any cell exceeding threshold-used in notebook battery packs and UPS backup systems to prevent cell damage during charging faults.

For engineers reviewing the BQ294702DSGT datasheet, BQ294702DSGT pinout, BQ294702DSGT application, or BQ294702DSGT equivalent, key selection considerations include its 4.300 V fixed OVP level, 8-pin WSON (2.0 mm × 2.0 mm) package, 1 µA quiescent current, <100 nA per-cell leakage, and support for 2S–4S configurations with independent cell voltage sensing.

Technical Context

The BQ294702DSGT implements second-level overvoltage protection using independent analog comparators per cell input (V1–VSS through V4–V3), with factory-trimmed 4.300 V threshold and 300 mV hysteresis. Its delay timer relies on external CD pin capacitor discharge (0.1 µF typical), with built-in open/short detection ensuring fail-safe activation even if the capacitor fails.

It operates across –40°C to +85°C, accepts 3 V–20 V unregulated VDD supply, and delivers 4.5 mA source current on the active-high OUT pin. The device enters low-power monitoring mode when all cells remain below VOV, drawing only ~1 µA total supply current while maintaining sub-100 nA input leakage per sense node.

Key Specifications

Pinout & Package

Package: 8-pin WSON (DSG), 2.00 mm × 2.00 mm, exposed thermal pad (PowerPAD™) requiring connection to VSS on PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ294702DSGT, BQ294703DSGT offers a marginally higher OVP setpoint for enhanced compatibility with high-voltage cathode materials, while BQ294704DSGT serves legacy 4.40 V systems-neither provides pin-compatible drop-in replacement without verifying downstream logic thresholds and fuse timing margins.

Availability

BQ294702DSGT is available at Aetrix Electronics and suitable for notebook battery packs, UPS backup modules, and portable medical devices requiring stable component supply, long-lifecycle assurance, and RoHS-compliant WSON packaging.

Supply support for BQ294702DSGT 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 safety ICs.

The BQ2947 family was designed specifically for second-level hardware overvoltage protection in multi-cell Li-ion battery packs, targeting high-reliability portable and backup power applications where firmware-independent safety is mandatory.

FAQ

What is the exact overvoltage protection threshold of the BQ294702DSGT?

The BQ294702DSGT has a factory-programmed overvoltage protection threshold of 4.300 V, with ±10 mV accuracy at 25°C and ±54 mV maximum drift across –40°C to +110°C. This value is laser-trimmed during manufacturing and cannot be adjusted externally. The BQ294702DSGT maintains this precise trip point across its full operating temperature and supply voltage range, making it suitable for safety-critical battery pack designs where consistent voltage limiting is required.

Does the BQ294702DSGT support 2-cell or 3-cell battery configurations?

Yes, the BQ294702DSGT supports 2S, 3S, and 4S Li-ion configurations. For 2S operation, V3 and V4 pins are shorted to V2; for 3S, V4 is shorted to V3 - both per TI's official application guidance. All four sense inputs (V1–VSS to V4–V3) remain electrically valid, and the IC automatically adapts monitoring scope without configuration registers or external components. The BQ294702DSGT retains its 4.300 V per-cell OVP threshold and 300 mV hysteresis regardless of stack size.

How is the overvoltage delay time set on the BQ294702DSGT?

The BQ294702DSGT uses an external capacitor connected to the CD pin to set the overvoltage delay time. With a 0.1 µF capacitor, the nominal delay is 1–2 seconds, calculated as t_CD = K × C_CD, where K ranges from 10 to 20. The BQ294702DSGT includes built-in diagnostics that detect open or shorted CD capacitors and force immediate OUT assertion in those fault conditions - ensuring no loss of protection due to timing component failure.

What is the output drive capability of the BQ294702DSGT OUT pin?

The BQ294702DSGT features a CMOS active-high output capable of sourcing 4.5 mA at VDD = 14.4 V with OUT = 0 V, and sinking up to 14 mA when pulled high by an external resistor. Output voltage reaches VDD – 0.3 V under load, enabling direct interface with standard logic-level NMOS gate drivers used in fuse-blow circuits. The BQ294702DSGT does not support open-drain configuration - only active-high output is available in this variant.

Can the BQ294702DSGT be used in automotive applications?

The BQ294702DSGT is specified for –40°C to +85°C ambient operation and carries industrial-grade qualification, but it is not AEC-Q200 qualified or rated for automotive under-hood environments. While it may function in cabin-mounted battery accessories, TI does not recommend the BQ294702DSGT for primary EV/HEV traction battery systems or ADAS power domains. For automotive use, designers should select explicitly qualified alternatives - the BQ294702DSGT remains optimized for consumer and industrial portable power applications.