Texas Instruments BQ24304DSGT

Overview

BQ24304DSGT from Texas Instruments is a Li-ion battery front-end protection IC designed for low-power handheld devices. It provides simultaneous input overvoltage (10.5 V), input overcurrent (300 mA), and battery overvoltage (4.35 V) protection with 4.5 V regulated output, thermal shutdown, and enable control - all in an 8-pin 2 mm × 2 mm WSON package.

For engineers reviewing the BQ24304DSGT datasheet, BQ24304DSGT pinout, BQ24304DSGT application, or BQ24304DSGT equivalent, this device serves as a critical safety guard between AC adapters and Li-ion charging circuits - especially where compact size, fast transient immunity, and precise voltage clamping are required.

Technical Context

The BQ24304DSGT operates as a linear regulator with internal N-channel FET (Q1) between IN and OUT, delivering regulated 4.5 V output up to 250 mA while continuously monitoring VIN, IIN, and VBAT. Its protection logic includes deglitch timers (tDGL(PGOOD) = 8 ms, tDGL(BOVP) = 176 μs), blanking windows (tBLANK(OVP) = 64 μs, tBLANK(OCP) = 5 ms), and soft-start/soft-stop gate control to suppress inrush and ringing.

It supports optional reverse-polarity protection via external P-FET driven by PGATE (clamped at 15 V typical), features CE-active-low enable with internal 200 kΩ pull-down, and senses battery voltage through high-impedance VBAT pin (IVBAT = 10 nA) with 275 mV hysteresis on battery OVP.

Key Specifications

Pinout & Package

Package: 2 mm × 2 mm, 8-pin WSON (DSG) with exposed thermal pad connected to VSS - requires PCB copper pad and thermal vias for reliable heat dissipation and EMI control.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Li-ion front-end protection applications.

Compared with BQ24304DSGT, BQ24300DSGT delivers +1.0 V higher regulated output but same protection timing and thermal behavior, while BQ24305DSGT offers intermediate 5.0 V regulation - all three share identical pinout, package, and functional safety architecture for drop-in voltage-scaling flexibility.

Availability

BQ24304DSGT is available at Aetrix Electronics and suitable for Bluetooth headsets, low-power handheld devices, USB-powered wearables, industrial handheld scanners, and portable medical sensors requiring stable component supply across production lifecycles.

Supply support for BQ24304DSGT 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 and protection ICs.

The bq2430x family was engineered specifically for front-end safety in single-cell Li-ion charging systems - delivering integrated overvoltage, overcurrent, and battery overvoltage protection in miniature WSON packages for space-constrained portable electronics.

FAQ

What is the primary function of the BQ24304DSGT in a Li-ion charging system?

The BQ24304DSGT acts as a dedicated front-end protection IC placed between the AC adapter and the main charger IC (e.g., bq24080). It continuously monitors input voltage, input current, and battery voltage - regulating output to 4.5 V while disabling power delivery upon detection of overvoltage (10.5 V), overcurrent (300 mA), or battery overvoltage (4.35 V). Its role is purely protective and does not perform charging algorithm control.

Does the BQ24304DSGT require external components to operate, and which ones are mandatory?

Yes - the BQ24304DSGT requires three mandatory external components: a ≥0.1 μF ceramic capacitor from IN to VSS, a ≥1 μF ceramic capacitor from OUT to VSS, and a 100–470 kΩ resistor (RBAT) between VBAT and the Li-ion pack positive terminal. The RBAT resistor is critical for fault isolation; omitting it risks exposing the battery to up to 30 V during IC failure.

How does the BQ24304DSGT handle input voltage transients, and what is its immunity specification?

The BQ24304DSGT uses a 64 μs blanking window (tBLANK(OVP)) after detecting an overvoltage event - allowing brief transients (e.g., ≤100 ns spikes from cable inductance) to pass without triggering shutdown. It also achieves 15 kV ESD immunity on the IN pin per IEC 61000-4-2 (contact discharge) when bypassed with a 1.0 μF low-ESR ceramic capacitor, making it robust in real-world adapter plug/unplug scenarios.

Can the BQ24304DSGT be used without the VBAT connection, and what is the impact?

Yes - if battery overvoltage protection is not required, the VBAT pin must be connected directly to VSS (not left floating). Doing so disables the BVOVP function while preserving all other protections (OVP, OCP, thermal shutdown). Leaving VBAT unconnected violates the datasheet and may cause undefined behavior or reduced reliability due to internal node floating.

What is the thermal performance limit of the BQ24304DSGT, and how is thermal management implemented on PCB?

The BQ24304DSGT shuts down at 150 °C junction temperature (TJ(OFF)) and re-enables at 130 °C (150 °C – 20 °C hysteresis). To maintain safe operation, the exposed thermal pad must be soldered to a PCB copper area connected to the VSS plane via ≥6 thermal vias (0.3 mm diameter, 0.6 mm pitch). With this layout, RθJA is 75 °C/W - enabling continuous 250 mA operation at ambient ≤65 °C.