Texas Instruments BQ24308DSGT

Overview

BQ24308DSGT from Texas Instruments is an integrated Li-ion battery front-end protection IC that provides simultaneous input overvoltage (6.3 V), input overcurrent (700 mA typical), and battery overvoltage (4.35 V) protection with thermal shutdown and 5-V LDO-mode regulation. It features internal FET control, programmable OCP via ILIM pin, and PGATE output for external reverse-polarity P-FET-used in mobile phone charging circuits to isolate faulty adapters before damage occurs.

For engineers reviewing the BQ24308DSGT datasheet, BQ24308DSGT pinout, BQ24308DSGT application, or BQ24308DSGT equivalent, key selection considerations include its 2 mm × 2 mm WSON-8 package, 30-V absolute max input rating, soft-stop current limiting, deglitch-timed fault recovery, and CE-controlled enable/disable functionality in space-constrained portable power systems.

Technical Context

The BQ24308DSGT implements three independent protection loops: input overvoltage detection with 0.2–1 µs propagation delay and 8-ms recovery; input overcurrent limiting with 5-ms blanking and 64-ms recovery; and battery overvoltage monitoring with 176-µs deglitch and soft-stop turnoff. All thresholds are internally fixed except IOCP, which scales linearly with external RILIM.

Its functional architecture integrates a charge-pump bias generator, bandgap reference, UVLO (2.7 V), OVP comparator, OCP comparator with current-sense amplifier, BOVP comparator, thermal shutdown circuit, and PGATE driver with 13–17 V clamp-enabling robust fault isolation without external controllers in single-cell Li+ charging front-ends.

Key Specifications

Pinout & Package

Package: 2 mm × 2 mm, 8-pin WSON with exposed thermal pad (DSG). Thermal pad must be soldered to PCB ground plane for thermal performance and electrical reference.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS259211DRCR, BQ24308DSGT delivers integrated battery-side safety and adapter polarity protection in one chip; versus BQ24314DSGR, it trades higher voltage/current headroom for cost-sensitive consumer applications where 26-V/1.5-A limits are sufficient.

Availability

BQ24308DSGT is available at Aetrix Electronics and suitable for mobile phones, Bluetooth headsets, MP3 players, and low-power handheld devices requiring stable component supply across production lifecycles.

Supply support for BQ24308DSGT 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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for portable electronics.

The BQ24308DSGT belongs to TI's battery front-end protection product line, designed specifically to safeguard single-cell Li+ charging paths against adapter faults, overcurrent events, and battery overvoltage-targeting compact, cost-sensitive consumer devices.

FAQ

What protection functions does the BQ24308DSGT provide?

The BQ24308DSGT provides three independent hardware-based protections: input overvoltage (6.3 V), input overcurrent (700 mA typical, programmable up to 1.5 A), and battery overvoltage (4.35 V). It also includes thermal shutdown (145 °C), undervoltage lockout (2.7 V), and soft-stop current limiting. These functions operate autonomously without firmware, making BQ24308DSGT ideal for fail-safe Li+ charging front-ends.

Can the BQ24308DSGT be used without an external P-FET?

Yes, the BQ24308DSGT operates fully without an external P-FET-the internal FET handles all OVP, OCP, and BOVP protection. The PGATE pin is optional and only required if reverse polarity protection (up to −30 V) is needed. When unused, PGATE remains inactive and does not affect BQ24308DSGT functionality or power consumption.

How is the input overcurrent threshold adjusted on the BQ24308DSGT?

The BQ24308DSGT's input overcurrent threshold is increased by connecting an external resistor RILIM between the ILIM pin and VSS. The programmed threshold follows IOCP(program) = 700 mA + (25,000 Ω·A ÷ RILIM). For example, a 31-kΩ resistor raises the threshold to ~1.5 A. No resistor yields the base 700 mA setting-no trimming or calibration is required.

What is the purpose of the VBAT pin on the BQ24308DSGT?

The VBAT pin on the BQ24308DSGT senses battery voltage for battery overvoltage protection. It must be connected to the battery positive terminal through a series resistor (RBAT = 100–470 kΩ) to limit fault current in case of internal failure. Direct connection risks exposing the battery to up to 30 V-RBAT ensures worst-case fault current stays below 270 µA, meeting IEC 62368-1 safety requirements.

Does the BQ24308DSGT require external capacitors, and if so, what values?

Yes, the BQ24308DSGT requires two mandatory ceramic capacitors: ≥0.1 µF placed between IN and VSS (close to Pin 1), and ≥1 µF between OUT and VSS (close to Pin 8). These stabilize operation, suppress input transients, and improve OVP response time. CIN prevents voltage spikes from cable inductance; COUT enhances current-limit loop speed during fast OVP events-both are critical for reliable protection.