Texas Instruments BQ29737DSER

Overview

BQ29737DSER from Texas Instruments is a single-cell Li-ion/Li-polymer battery protection IC that integrates overvoltage (4.250 V), undervoltage (2.800 V), charge/discharge overcurrent (–0.050 V / 0.100 V), and short-circuit (0.3 V) detection with factory-programmed thresholds and fixed timing delays (96 ms UVP, 16 ms OCC, 16 ms OCD). It operates from –40°C to +85°C with 4 µA normal-mode current and drives external CHG/DSG FETs via COUT/DOUT outputs in a 1.50 mm × 1.50 mm WSON-6 package.

For engineers reviewing the BQ29737DSER datasheet, BQ29737DSER pinout, BQ29737DSER application, or BQ29737DSER equivalent, this device delivers precision cell-level safety monitoring for compact portable electronics where low quiescent current, zero-voltage charging capability (≥1.7 V), and ±5 mV OCP sensing accuracy are critical selection criteria.

Technical Context

The BQ29737DSER implements analog voltage comparators with internal reference and programmable hysteresis for OVP/UVP, plus differential V_DS sensing across external FETs for OCC/OCD/SCP-enabling accurate current-limit detection without sense resistors. Its fault logic uses fixed, non-volatile timer values (e.g., 96 ms UVP delay, 16 ms OCD delay) and automatic recovery timers (8 ms for UVP/OCC/OCD).

It operates in two power states: NORMAL mode (4 µA I_CC) for active protection and Shutdown mode (100 nA I_Q) for storage. The device supports zero-voltage charging initiation at ≥1.7 V BAT–V– and inhibits charging below 0.75 V, using V– as a dedicated sense node referenced to pack– for all overcurrent functions.

Key Specifications

Pinout & Package

Package: WSON-6 (DSE), 1.50 mm × 1.50 mm × 0.75 mm body, wettable flank terminals, exposed thermal pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29737DSER, BQ29732DSER raises the OCD threshold to reduce false triggering in high-pulse-load applications, while BQ29733DSER cuts UVP delay to 20 ms for faster low-voltage cutoff - both retain identical 1.50 mm × 1.50 mm WSON-6 packaging and zero-voltage charging capability.

Availability

BQ29737DSER 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 production programs.

Supply support for BQ29737DSER 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 with broad portfolio coverage, manufacturing scale, and long-term product longevity commitments.

The BQ297xx family is designed specifically for cost-effective, highly integrated single-cell Li-ion/Li-polymer battery protection - emphasizing ultra-low quiescent current, factory-programmed reliability, and minimal external component count.

FAQ

What is the overvoltage protection threshold of the BQ29737DSER?

The BQ29737DSER has a factory-programmed overvoltage protection (OVP) threshold of 4.250 V with ±10 mV accuracy at 25°C. This value is laser-trimmed and non-volatile, ensuring consistent cell safety without external adjustment. The OVP release hysteresis is 100 mV, meaning the CHG FET re-enables only after battery voltage drops to 4.150 V. This threshold is optimized to prevent lithium plating while allowing full charge termination in standard 4.2 V nominal cells.

How does the BQ29737DSER detect discharge overcurrent?

The BQ29737DSER detects discharge overcurrent by measuring the voltage difference between its V– and VSS pins - effectively sensing V_DS across the external discharge FET. Its factory-set OCD threshold is 0.100 V ±10 mV at 25°C, triggering DOUT disable after a fixed 16 ms delay. This method eliminates the need for an external sense resistor, reducing BOM cost and PCB area while maintaining ±5 mV typical sensing accuracy across temperature.

Does the BQ29737DSER support charging of fully depleted batteries?

Yes, the BQ29737DSER supports zero-voltage charging: it allows the CHG FET to enable when BAT–V– ≥ 1.7 V, enabling safe pre-charge of deeply discharged cells. Charging is inhibited if BAT–V– falls below 0.75 V. This function is implemented in hardware with no firmware dependency, making it ideal for sealed battery packs where manual reset is impossible. The feature operates independently of host system control.

What package type and dimensions does the BQ29737DSER use?

The BQ29737DSER uses the WSON-6 (DSE) package: 1.50 mm × 1.50 mm × 0.75 mm body size with wettable flank terminals and an exposed thermal pad. This ultra-compact, leadless封装 supports automated optical inspection (AOI) and provides superior thermal performance (θ_JA = 190.5°C/W) for space-constrained portable designs. Pinout matches industry-standard 6-pin WSON footprints, enabling drop-in compatibility with other BQ297xx variants.

What is the quiescent current consumption of the BQ29737DSER in active mode?

The BQ29737DSER draws 4 µA typical current in NORMAL mode at 3.8 V BAT and 25°C, with a maximum of 5.5 µA across temperature and voltage range. In Shutdown mode, it consumes only 100 nA - enabling multi-year shelf life in battery-powered devices. This ultra-low I_CC is achieved through optimized internal biasing and clock gating, making BQ29737DSER suitable for always-on portable electronics where self-discharge must be minimized.