Texas Instruments BQ29737DSET

Overview

BQ29737DSET from Texas Instruments is a single-cell Li-ion/Li-polymer battery protection IC that provides overvoltage (4.250 V), undervoltage (2.800 V), charge/discharge overcurrent (–50 mV / 100 mV), and short-circuit protection with factory-programmed thresholds and fixed timing delays. It drives external CHG/DSG FETs, supports zero-voltage charging (≥1.7 V), and operates from –40°C to +85°C in portable power systems.

For engineers reviewing the BQ29737DSET datasheet, BQ29737DSET pinout, BQ29737DSET application, or BQ29737DSET equivalent, this page delivers verified electrical parameters, WSON-6 package mapping, functional pin roles, real-world use cases in mobile handsets and tablets, and two validated alternative parts with documented threshold and timing differences.

Technical Context

The BQ29737DSET implements analog voltage sensing across external FETs for precise overcurrent detection (±5 mV typical accuracy) and uses internal comparators with hysteresis to trigger gate drive outputs. Its fault detection logic includes independent timers for OVP (1 s), UVP (96 ms), OCD (16 ms), OCC (16 ms), and SCP (250 µs), all factory-programmed and non-adjustable.

It operates in NORMAL mode at 4 µA quiescent current and enters shutdown at 100 nA, with BAT supply range of –0.3 V to 8 V and V– input referenced to pack–. The device features dedicated COUT and DOUT outputs driving NMOS FET gates, and supports zero-voltage charging initiation when BAT ≥ 1.7 V and inhibition below 0.75 V.

Key Specifications

Pinout & Package

The BQ29737DSET is housed in a 6-pin WSON (DSE) package measuring 1.50 mm × 1.50 mm × 0.75 mm, with wettable flanks and no exposed thermal pad. Pin 1 is NC (no connection); pins are arranged in standard top-view orientation with BAT at position 5 and VSS at position 4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29732DSET and BQ29733DSET, the BQ29737DSET offers the lowest OVP (4.250 V) and shortest OCD delay (16 ms) among factory-programmed variants - making it optimal for conservative protection of standard 4.2 V nominal Li-ion cells where early fault intervention is prioritized.

Availability

BQ29737DSET is available at Aetrix Electronics and suitable for mobile handsets, tablet PCs, and handheld data terminals requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for BQ29737DSET 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 delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The BQ297xx family is designed specifically for cost-effective, highly integrated single-cell Li-ion/Li-polymer battery protection - eliminating external resistors, capacitors, and microcontrollers in space-constrained portable applications.

FAQ

What is the overcharge protection voltage threshold for BQ29737DSET?

The BQ29737DSET has a factory-programmed overcharge protection (OVP) threshold of 4.250 V ±10 mV at 25°C, with ±20 mV variation across –40°C to +85°C. This value is permanently set during manufacturing and cannot be adjusted externally. The BQ29737DSET uses this threshold to disable the CHG FET via the COUT pin when the BAT-to-VSS voltage exceeds the limit, preventing cell degradation. Recovery occurs after a fixed 12 ms timer once voltage falls below 4.150 V.

Does BQ29737DSET support zero-voltage charging, and what are the conditions?

Yes, the BQ29737DSET supports zero-voltage charging initiation when the BAT pin voltage reaches ≥1.7 V, enabling safe recharge of deeply depleted cells. Charging is inhibited if BAT drops below 0.75 V. This function operates independently of external controllers and relies on internal comparators monitoring BAT relative to V– and VSS. The BQ29737DSET implements this feature with no additional components, making it ideal for consumer devices with infrequent usage patterns.

What package type and dimensions does BQ29737DSET use?

The BQ29737DSET is packaged in a 6-pin WSON (DSE) package measuring 1.50 mm × 1.50 mm × 0.75 mm, with wettable flanks for automated optical inspection. It has no exposed thermal pad and uses a standard pinout: Pin 1 (NC), Pin 2 (COUT), Pin 3 (DOUT), Pin 4 (VSS), Pin 5 (BAT), Pin 6 (V–). The BQ29737DSET's compact footprint supports high-density PCB layouts in thin-profile portable electronics.

How does BQ29737DSET detect discharge overcurrent, and what is its accuracy?

The BQ29737DSET detects discharge overcurrent by measuring the voltage difference between V– and VSS pins, corresponding to the Vds across the external DSG FET. Its factory-set OCD threshold is 100 mV ±10 mV at 25°C, with ±15 mV variation over –40°C to +85°C. Detection triggers DOUT to pull low after a fixed 16 ms delay. The BQ29737DSET achieves this accuracy using trimmed internal comparators and differential sensing - eliminating the need for external sense resistors and associated power loss.

What are the quiescent current specifications for BQ29737DSET in active and shutdown modes?

The BQ29737DSET draws 4 µA typical current in NORMAL mode (BAT = 3.8 V, V– = 0 V) and 0.1 µA in power-down mode (BAT = V– = 1.5 V). These values are measured across the full operating temperature range and enable multi-year battery shelf life in always-on portable devices. The BQ29737DSET automatically transitions to low-current states based on supply conditions - no external enable signal is required to achieve 100 nA shutdown current.