Texas Instruments BQ29733DSET

Overview

BQ29733DSET from Texas Instruments is a single-cell Li-ion/Li-polymer battery protection IC that integrates overvoltage (4.400 V), undervoltage (2.800 V), charge/discharge overcurrent (–0.100 V / 0.120 V), and short-circuit (0.3 V) detection with factory-programmed thresholds and fixed timing delays (1.25 s OVP, 20 ms UVP, 8 ms OCD/OCC, 250 µs SCP). It operates from –40°C to +85°C with 4 µA NORMAL-mode current and supports zero-voltage charging for deeply depleted cells in portable power systems.

For engineers reviewing the BQ29733DSET datasheet, BQ29733DSET pinout, BQ29733DSET application, or BQ29733DSET equivalent, this device delivers precision cell-level fault monitoring across external FETs with ±10 mV typical OCP accuracy at 25°C, low-quiescent-current operation, and WSON-6 (1.50 mm × 1.50 mm) packaging optimized for space-constrained battery packs in handheld electronics.

Technical Context

The BQ29733DSET implements analog voltage sensing across external power FETs to detect overcurrent conditions during charge and discharge, using differential inputs (V– and VSS) referenced to pack negative. Its internal comparators trigger gate-drive outputs (COUT and DOUT) with programmable delay timers-1.25 s for overcharge, 20 ms for over-discharge, and 8 ms for overcurrent events-followed by fixed recovery delays (12 ms for OVP, 8 ms for others).

It features dual FET drive outputs: COUT controls the charge FET (NMOS) with high-side sourcing relative to V–, while DOUT controls the discharge FET (NMOS) with high-side sourcing relative to VSS. The device includes factory-trimmed thresholds, zero-voltage charging enable above 1.7 V, and operates without external charger control logic in autonomous protection mode.

Key Specifications

Pinout & Package

Package: WSON-6 (DSE), 1.50 mm × 1.50 mm × 0.75 mm body, wettable flank, no lead.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ29733DSET, BQ29732DSET offers higher discharge overcurrent immunity but reduced overvoltage margin, while BQ29737DSET provides the strictest charge overcurrent sensitivity and lowest OVP-enabling differentiated safety tuning across product variants without layout changes.

Availability

BQ29733DSET is available at Aetrix Electronics and suitable for smartphone battery packs, tablet PC power management, and handheld data terminals requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for BQ29733DSET 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 over 50 years of innovation in battery safety and energy efficiency.

The BQ297xx family is designed specifically for cost-sensitive, space-constrained single-cell Li-ion/Li-polymer battery protection - delivering factory-programmed accuracy, ultra-low power, and integrated FET drive in a 1.5-mm WSON package.

FAQ

What protection functions does the BQ29733DSET provide?

The BQ29733DSET provides overcharge protection (OVP at 4.400 V), over-discharge protection (UVP at 2.800 V), charge overcurrent protection (OCC at –0.100 V), discharge overcurrent protection (OCD at 0.120 V), and load short-circuit protection (SCP at 0.3 V). All thresholds are factory-programmed and include fixed delay timers and recovery delays. The BQ29733DSET executes these protections autonomously without host MCU intervention.

How does the BQ29733DSET support zero-voltage charging?

The BQ29733DSET enables zero-voltage charging when the charger voltage applied to the BAT pin exceeds 1.7 V, allowing recovery of deeply depleted cells down to 0 V. This function is implemented internally and does not require external enable signals. The BQ29733DSET asserts COUT high once the condition is met, permitting charge FET conduction even when cell voltage is near zero - a key feature for improving device usability after long-term storage.

What is the package type and footprint of the BQ29733DSET?

The BQ29733DSET uses a 6-pin WSON package (also labeled DSE), with nominal dimensions of 1.50 mm × 1.50 mm × 0.75 mm and wettable flanks for automated optical inspection. It has no exposed thermal pad and requires standard reflow profiles for lead-free assembly. The BQ29733DSET pinout is fixed: BAT (5), COUT (2), DOUT (3), NC (1), VSS (4), V– (6).

Can the BQ29733DSET operate without a battery charger present?

Yes, the BQ29733DSET operates autonomously in NORMAL mode (4 µA) or Shutdown mode (100 nA) without requiring an active charger or host controller. It continuously monitors BAT, V–, and VSS to detect faults and assert COUT/DOUT as needed. The BQ29733DSET is designed for standalone protection in systems where the charger may be disconnected or absent during operation or storage.

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

COUT and DOUT are high-side NMOS gate drivers referenced to V– and VSS respectively. At 3.8 V BAT, COUT delivers VOH ≥3.4 V (IOH = –30 µA) and VOL ≤0.5 V (IOL = 30 µA); DOUT delivers VOH ≥3.4 V and VOL ≤0.5 V under same conditions. These outputs directly drive external NMOS FET gates without level-shifting components. The BQ29733DSET specifies pull-up resistance on V– (100–550 kΩ) and sink current (8–24 µA) to support accurate differential sensing.