Texas Instruments BQ29706DSET

Overview

BQ29706DSET from Texas Instruments is a single-cell Li-ion/Li-polymer battery protection IC that integrates overvoltage (OVP: 3.85 V), undervoltage (UVP: 2.50 V), discharge overcurrent (OCD: 200 mV), charge overcurrent (OCC: –150 mV), and short-circuit (SCD: 0.6 V) detection with factory-programmed thresholds and fixed timing delays. It drives external CHG/DSG FETs via COUT/DOUT outputs and supports zero-voltage charging (≥1.7 V start). It operates across –40°C to +85°C in portable power systems.

For engineers reviewing the BQ29706DSET datasheet, BQ29706DSET pinout, BQ29706DSET application, or BQ29706DSET equivalent, this device delivers precision cell-level fault monitoring with ultra-low quiescent current (4 µA in NORMAL mode, 100 nA in shutdown), ±5 mV OCD sensing accuracy, and WSON-6 (1.5 mm × 1.5 mm) packaging optimized for space-constrained battery packs in handheld electronics.

Technical Context

The BQ29706DSET implements analog voltage and current fault detection using differential sensing across external FETs (V– to VSS for OCD/SCD; VSS to V– for OCC) with internal comparators and fixed-delay timers. Its architecture avoids microcontroller dependency by embedding factory-programmed thresholds and recovery timers - OVP recovery delay is 12 ms; UVP/OCC/OCD recovery is 8 ms.

It features dual gate-drive outputs: COUT (charge FET control, referenced to V–) and DOUT (discharge FET control, referenced to VSS), each capable of driving NMOS FETs with VOH ≥ 3.4 V and VOL ≤ 0.5 V at 30 µA load. The BAT supply input accepts up to 8 V, while V– tolerates voltages down to BAT – 25 V, enabling robust operation under charger transients and pack asymmetry.

Key Specifications

Pinout & Package

Package: WSON-6 (DSE), 1.50 mm × 1.50 mm × 0.75 mm body size, wettable flank terminals, no exposed thermal pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29706DSET, BQ29702DSET raises OVP/UVP thresholds for higher-energy cells, while BQ29733DSET reduces OVP delay and OCD trip point for responsive, high-precision current limiting - both require revalidation of protection timing and voltage margins in the target battery system.

Availability

BQ29706DSET is available at Aetrix Electronics and suitable for smartphone battery packs, tablet PC power management, and handheld data terminals requiring stable component supply with guaranteed long-term manufacturability and TI's full product lifecycle support.

Supply support for BQ29706DSET 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 experience in battery safety ICs and automotive-grade reliability.

The BQ297xx family is designed specifically for cost-sensitive, space-constrained single-cell Li-ion/Li-polymer battery packs in consumer electronics, delivering integrated analog protection without firmware or external timing components.

FAQ

What protection functions does the BQ29706DSET provide?

The BQ29706DSET provides overcharge protection (OVP at 3.85 V), over-discharge protection (UVP at 2.50 V), discharge overcurrent protection (OCD at 200 mV), charge overcurrent protection (OCC at –150 mV), and load short-circuit detection (SCD at 0.6 V). All thresholds are factory-programmed and non-adjustable. Each fault triggers COUT or DOUT to drive external FETs into cutoff with fixed delay timers - for example, UVP activates DOUT after 144 ms, and SCD responds in 250 µs. The BQ29706DSET also enables zero-voltage charging when BAT–V– ≥ 1.7 V.

How is the BQ29706DSET configured for different battery chemistries?

The BQ29706DSET is not user-configurable - its protection thresholds and timing parameters are factory-programmed during wafer test and cannot be modified in-system. The "6" in BQ29706DSET denotes the specific configuration: OVP = 3.85 V, UVP = 2.50 V, OCD = 200 mV, OCC = –150 mV, SCD = 0.6 V, tUVPD = 144 ms, and tOVPD = 1.25 s. To match other chemistries, designers must select a different variant (e.g., BQ29702DSET for 4.35 V OVP) rather than reprogram the BQ29706DSET.

What are the key electrical characteristics of the COUT and DOUT outputs?

COUT and DOUT are push-pull gate drivers referenced to V– and VSS respectively. At BAT = 3.8 V, COUT delivers VOH ≥ 3.4 V and VOL ≤ 0.5 V into 30 µA load; DOUT delivers VOH ≥ 3.4 V and VOL ≤ 0.5 V (at BAT = 2 V). Both outputs sink/source sufficient current to directly drive standard logic-level NMOS FETs without external buffers. The BQ29706DSET datasheet specifies no minimum gate capacitance requirement, and typical designs use 5 MΩ pull-down resistors from COUT to PACK– and DOUT to VSS for controlled FET turn-off.

Does the BQ29706DSET support bidirectional current sensing?

Yes - the BQ29706DSET supports bidirectional current sensing through separate differential inputs: V– to VSS measures discharge current (OCD/SCD), while VSS to V– measures charge current (OCC). This architecture allows independent detection of overcurrent in both directions using the same sense node (V–), eliminating the need for dual sense resistors. The BQ29706DSET achieves ±5 mV typical OCD accuracy and ±15 mV worst-case OCC accuracy across temperature, enabling precise, low-loss current monitoring with a single external sense path.

What is the role of the V– pin in the BQ29706DSET?

The V– pin serves as the primary differential sense input for all current-related protections: discharge overcurrent (OCD), charge overcurrent (OCC), and short-circuit (SCD). It forms one side of the measurement pair with VSS (for OCD/SCD) or BAT (for OCC). Internally, V– connects to a 100–550 kΩ pullup to BAT and sinks 8–24 µA to VSS, enabling direct connection to the pack negative terminal via a 2.2 kΩ resistor. In the BQ29706DSET, V– also enables zero-voltage charging detection when BAT–V– ≥ 1.7 V, making it central to both safety and usability functions.