Texas Instruments BQ29705DSET

Overview

BQ29705DSET from Texas Instruments is a single-cell Li-ion/Li-polymer battery protection IC that monitors cell voltage, charge/discharge current via external FET V_DS sensing, and provides overvoltage (4.425 V), undervoltage (2.500 V), charge/discharge overcurrent (–0.100 V / 0.150 V), and short-circuit (0.5 V) protection with factory-programmed thresholds and timers. It operates in NORMAL mode at 4 µA and supports zero-voltage charging for deeply depleted cells in portable power systems.

For engineers reviewing the BQ29705DSET datasheet, BQ29705DSET pinout, BQ29705DSET application, or BQ29705DSET equivalent, this device delivers precision fault detection (±10 mV OVP/UVP accuracy at 25°C), ultra-low quiescent current, and integrated gate drive outputs for external CHG/DSG FETs - critical for space-constrained, long-life battery packs in handheld electronics.

Technical Context

The BQ29705DSET implements analog comparator-based fault detection with internal reference and programmable hysteresis, using differential sensing across V– and VSS to detect discharge overcurrent (VOCD), and across VSS and V– to detect charge overcurrent (VOCC). Its timing logic uses an internal oscillator (1.255 kHz typical) to enforce fixed delay timers before FET shutdown.

Fault recovery is timer-gated: OVP recovers after 12 ms, while UVP/OCC/OCD recover after 8 ms once conditions return within threshold windows. The device requires no external microcontroller or charger enable signal to operate its protection functions, enabling autonomous operation in standalone battery packs.

Key Specifications

Pinout & Package

Package: 6-pin WSON (DSE), 1.50 mm × 1.50 mm × 0.75 mm, moisture sensitivity level (MSL) 2 per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29704DSET and BQ29717DSET, the BQ29705DSET provides the highest OCD threshold (0.150 V) among factory-configured variants, delivering superior noise immunity in electrically noisy environments - critical for handheld scanners and industrial data collectors where EMI-induced false trips must be minimized.

Availability

BQ29705DSET is available at Aetrix Electronics and suitable for tablet PCs, mobile handsets, and handheld data terminals requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing for medical and industrial OEM programs.

Supply support for BQ29705DSET 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 ICs for consumer and industrial markets.

The BQ297xx family is designed specifically for cost-sensitive, space-constrained single-cell Li-ion/Li-polymer battery packs - delivering integrated protection with minimal external components and factory-programmed reliability for high-volume portable electronics.

FAQ

What protection functions does the BQ29705DSET provide?

The BQ29705DSET provides overcharge protection (OVP at 4.425 V), over-discharge protection (UVP at 2.500 V), charge overcurrent protection (OCC at –0.100 V), discharge overcurrent protection (OCD at 0.150 V), and load short-circuit protection (SCP at 0.5 V). All thresholds are factory-programmed and temperature-compensated. The BQ29705DSET enforces these protections autonomously using internal comparators and timers without host processor involvement.

How does the BQ29705DSET support zero-voltage charging?

The BQ29705DSET enables zero-voltage charging when the voltage between BAT and V– reaches ≥1.7 V, allowing deeply depleted cells (0 V) to be safely preconditioned before full-rate charging begins. This function is implemented in hardware and requires no external control signals. The BQ29705DSET will not enable the CHG FET until this condition is met, preventing uncontrolled current into damaged cells.

What is the package type and footprint of the BQ29705DSET?

The BQ29705DSET uses a 6-pin WSON (DSE) package measuring 1.50 mm × 1.50 mm × 0.75 mm with 0.4-mm pin pitch. It features wettable flanks for automated optical inspection and complies with JEDEC MSL-2 moisture sensitivity standards. The BQ29705DSET's compact footprint supports high-density layouts in slim portable devices without requiring thermal vias for standard operation.

Can the BQ29705DSET be used without a battery charger controller?

Yes - the BQ29705DSET operates fully autonomously in NORMAL mode (4 µA) and requires no communication interface, clock input, or enable signal from a charger IC or microcontroller. It continuously monitors BAT, V–, and VSS to detect faults and drive COUT/DOUT outputs directly. The BQ29705DSET is explicitly designed for standalone protection in simple battery packs where system-level intelligence is unavailable or undesirable.

What are the key timing parameters for fault response in the BQ29705DSET?

The BQ29705DSET uses fixed factory-programmed timers: OVP delay = 1.25 s, UVP delay = 20 ms, OCD delay = 8 ms, OCC delay = 8 ms, and SCP delay = 250 µs. Recovery delays are also fixed: OVP recovery = 12 ms, UVP/OCC/OCD recovery = 8 ms. These values are trimmed during manufacturing and do not require configuration. The BQ29705DSET guarantees these timing windows across –40°C to +85°C.