Texas Instruments BQ24312DSGR

Overview

BQ24312DSGR from Texas Instruments is an integrated Li-ion battery front-end protection IC that provides input overvoltage (5.85 V typ), user-programmable input overcurrent (300–1500 mA range), and battery overvoltage (4.35 V) protection in a single 2 × 2 mm WSON-8 package. It features internal FET switching, thermal shutdown at 140°C, and active fault reporting via open-drain FAULT pin - deployed in mobile phones and Bluetooth headsets to safeguard charging circuits from adapter faults.

For engineers reviewing the BQ24312DSGR datasheet, BQ24312DSGR pinout, BQ24312DSGR application, or BQ24312DSGR equivalent, key selection considerations include programmable OCP threshold via ILIM resistor, 1.5-A continuous input current support, robust transient immunity with 64 μs OVP blanking time, and compatibility with 3–30 V input sources in space-constrained portable designs.

Technical Context

The BQ24312DSGR implements three independent protection loops: input overvoltage detection with 5.85 V threshold and 60 mV hysteresis, input overcurrent limiting controlled by external RILIM (15–90 kΩ), and fixed 4.35 V battery overvoltage cutoff with 275 mV hysteresis. Each fault triggers immediate FET Q1 turn-off and drives FAULT low.

It operates in three functional modes: POWER-DOWN below 2.7 V UVLO, OPERATION with soft-start and deglitch timing (8 ms PGOOD delay), and PROTECTION with counter-based latching (15 faults per cycle). The CE pin enables host-controlled enable/disable with internal pulldown, and FAULT status is disabled when CE is high.

Key Specifications

Pinout & Package

Package: 8-pin WSON (2.00 mm × 2.00 mm) with exposed thermal pad electrically connected to VSS - requires PCB copper pour tied to ground plane for thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar overvoltage and overcurrent protection applications.

Compared with BQ24312DSGR, BQ24314DSGR extends functionality with slew-rate control but increases complexity, while TPS259211DRCR offers higher voltage/current ratings at the cost of missing battery-side protection - making BQ24312DSGR uniquely suited for Li-ion front-end safety where all three protection domains (input OVP/OCP + battery OVP) are required.

Availability

BQ24312DSGR is available at Aetrix Electronics and suitable for mobile phones, Bluetooth headsets, and MP3 players requiring stable component supply with full lifecycle support and traceable sourcing.

Supply support for BQ24312DSGR 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 solutions, with leadership in power management and battery interface technologies.

The BQ24312DSGR belongs to TI's battery front-end protection product line, engineered specifically for Li-ion-powered portable electronics requiring integrated, autonomous overvoltage, overcurrent, and battery overvoltage safeguards in minimal footprint.

FAQ

What protection functions does the BQ24312DSGR provide?

The BQ24312DSGR provides three independent protection functions: input overvoltage protection (5.85 V threshold), user-programmable input overcurrent limiting (300–1500 mA), and fixed battery overvoltage cutoff (4.35 V). It also includes thermal shutdown at 140°C and undervoltage lockout at 2.7 V. All protections trigger internal FET disconnection and assert the open-drain FAULT pin low. The BQ24312DSGR integrates these functions into a single 2 × 2 mm WSON-8 package without requiring external controllers.

How is the overcurrent threshold set on the BQ24312DSGR?

The overcurrent threshold on the BQ24312DSGR is set by connecting an external resistor (RILIM) between the ILIM pin and VSS. The relationship is approximated by IOCP ≈ 25 ÷ RILIM (with current in amperes and resistance in kΩ). For example, a 24.9-kΩ resistor sets the threshold to ~1.0 A. RILIM must be between 15 kΩ and 90 kΩ to ensure valid operation. The BQ24312DSGR uses this resistor to configure protection without firmware or digital interfaces.

Does the BQ24312DSGR support reverse current flow from OUT to IN?

Yes, the BQ24312DSGR supports reverse current flow from OUT to IN when VOUT exceeds UVLO + 0.7 V (~3.4 V), enabling use cases like battery-powered accessory operation. In this mode, the internal FET conducts bidirectionally with the same 1.5-A current capability as forward flow. However, no overcurrent protection is active in the reverse direction. This behavior is intrinsic to the BQ24312DSGR's architecture and requires no configuration changes.

What is the role of the FAULT pin on the BQ24312DSGR?

The FAULT pin on the BQ24312DSGR is an active-low open-drain output that signals any fault condition: input overvoltage, input overcurrent, battery overvoltage, or thermal shutdown. It remains high-impedance during normal operation or when CE is high. To interface with a host microcontroller, an external pull-up resistor (e.g., 47 kΩ) is required. The BQ24312DSGR asserts FAULT low within microseconds of fault detection, enabling rapid system response without polling.

Can the BQ24312DSGR be used without a microcontroller?

Yes, the BQ24312DSGR can operate autonomously without a microcontroller. Its CE pin has an internal pulldown resistor, so leaving it unconnected or tying it to VSS enables continuous operation. All protection functions - OVP, OCP, BVOVP, and thermal shutdown - operate independently and latch faults internally. The FAULT pin provides optional status feedback, but the BQ24312DSGR delivers full safety coverage even in standalone configurations common in cost-sensitive portable devices.