Texas Instruments BQ24305DSGT

Overview

BQ24305DSGT from Texas Instruments is a Li-ion battery front-end protection IC that functions as a programmable linear regulator with integrated overvoltage (10.5 V), overcurrent (300 mA), and battery overvoltage (4.35 V) protection. It delivers regulated 5.0 V output to downstream charging circuitry, supports optional reverse-polarity protection via external P-FET, and operates in 2 mm × 2 mm 8-pin WSON (DSG) package for space-constrained portable power systems.

For engineers reviewing the BQ24305DSGT datasheet, BQ24305DSGT pinout, BQ24305DSGT application, or BQ24305DSGT equivalent, this device is selected for precise input fault detection, soft-start/soft-stop control, thermal shutdown (150 °C), and low-quiescent-current operation (95 μA standby) in single-cell Li+ battery management paths.

Technical Context

The BQ24305DSGT implements three independent protection loops-input overvoltage (OVP), input overcurrent (OCP), and battery overvoltage (BVOVP)-each with dedicated deglitch timing (tDGL(BOVP) = 176 μs, tBLANK(OVP) = 64 μs, tBLANK(OCP) = 5 ms) and hysteresis (VHYS-OVP = 100 mV, VHYS-BOVP = 275 mV). Its internal gate driver (PGATE) supports external P-channel MOSFETs with clamp-limited gate voltage (VGCLMP = 15 V typ) for reverse-polarity protection up to –30 V.

It operates as a series linear regulator below OVP threshold, maintaining 5.0 V ±150 mV output regulation (VO(REG)) across 0–125 °C and load currents up to 250 mA, with dropout voltage of 75 mV typical at 250 mA. Enable logic is active-low (CE), internally pulled down, with VIH = 1.4 V and IIL = 1 μA.

Key Specifications

Pinout & Package

The BQ24305DSGT uses an 8-pin WSON (DSG) package with exposed thermal pad connected internally to VSS. The thermal pad must be soldered to a PCB ground plane using ≥6 thermal vias for reliable thermal performance and electrical stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BQ24300DSGT and BQ24304DSGT, the BQ24305DSGT provides the optimal balance of 5.0 V compatibility with common single-cell charger ICs, precise 4.35 V battery cutoff, and minimal thermal overhead-making it the preferred choice for new designs requiring tight regulation and certified Li+ safety compliance.

Availability

BQ24305DSGT is available at Aetrix Electronics and suitable for Bluetooth headsets, low-power handheld devices, and USB-powered portable instruments requiring stable component supply, full production traceability, and long-term lifecycle support.

Supply support for BQ24305DSGT 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 solutions.

The bq2430x family was designed specifically for Li-ion battery front-end protection in portable electronics, integrating triple-fault monitoring, thermal safety, and compact packaging to replace discrete protection circuits in space- and reliability-critical applications.

FAQ

What is the primary function of the BQ24305DSGT in a battery charging system?

The BQ24305DSGT serves as a front-end protection IC between the input power source (e.g., USB adapter) and the main charger IC. It continuously monitors input voltage, input current, and battery voltage to prevent damage from overvoltage (10.5 V), overcurrent (300 mA), and battery overvoltage (4.35 V). The BQ24305DSGT regulates its OUT pin to 5.0 V and provides soft-start/soft-stop behavior to ensure safe power sequencing in portable Li+ systems.

Does the BQ24305DSGT require external components to implement battery overvoltage protection?

Yes-the BQ24305DSGT requires an external resistor (RBAT) between the battery positive terminal and the VBAT pin. TI recommends RBAT = 100–470 kΩ to limit fault current during IC failure while minimizing measurement error on the 4.35 V BVOVP threshold. The VBAT pin itself draws only 10 nA, so the resistor introduces negligible loading but is essential for functional and safety compliance.

Can the BQ24305DSGT be used without connecting the PGATE pin?

Yes-the PGATE pin is optional. If reverse-polarity protection is not required, PGATE may be left unconnected. The BQ24305DSGT still provides full input overvoltage, input overcurrent, and battery overvoltage protection using its internal FET. When PGATE is unused, the device operates in standard linear regulator mode with 5.0 V output regulation and all core protection features fully active.

What is the maximum input voltage the BQ24305DSGT can withstand before permanent damage occurs?

The absolute maximum input voltage (IN pin to VSS) for the BQ24305DSGT is 30 V, per TI's Absolute Maximum Ratings. However, recommended operating range is 3.3–26 V. Operation above 26 V risks triggering irreversible latch-up or thermal damage-even if within absolute max-so system design must ensure sustained input stays ≤26 V, with transient spikes limited by external clamping or filtering.

How does the BQ24305DSGT handle recovery after an overvoltage event?

After an input overvoltage condition clears (VIN drops below 10.5 V), the BQ24305DSGT waits 8 ms (tON(OVP)) before re-enabling the output. During this time, it performs a full soft-start sequence-including gate ramp control-to prevent inrush current and input voltage ringing. This controlled restart ensures downstream circuitry remains undisturbed and avoids repeated fault cycling due to marginal input conditions.