Texas Instruments TPS54331D

Overview

TPS54331D from Texas Instruments is a 28-V, 3-A non-synchronous step-down DC-DC converter with integrated 80-mΩ high-side MOSFET, fixed 570-kHz switching frequency, Eco-mode for light-load efficiency, and adjustable output down to 0.8 V. It serves as primary voltage regulator in industrial power supplies and consumer electronics requiring stable 5-V or 12-V rails from wide-input sources.

For engineers reviewing the TPS54331D datasheet, TPS54331D pinout, TPS54331D application, or TPS54331D equivalent, key selection criteria include input voltage range (3.5–28 V), shutdown current (1 μA), Eco-mode activation threshold (160 mA), thermal shutdown (165°C), and SOIC-8 package compatibility with PowerPAD™ thermal enhancement.

Technical Context

The TPS54331D implements constant-frequency peak-current mode control with internal slope compensation, enabling stable operation with ceramic output capacitors and simplified loop compensation. Its transconductance error amplifier (92 μA/V) interfaces directly with the COMP pin for external frequency compensation.

Eco-mode operates via pulse skipping when peak inductor current falls below 160 mA, clamping COMP at 0.5 V to halt switching; frequency foldback reduces switching frequency to 570 kHz / 2, /4, or /8 during overcurrent based on VSENSE voltage thresholds (0.2–0.6 V), while overvoltage transient protection disables the high-side MOSFET when VSENSE exceeds 109% × 0.8 V.

Key Specifications

Pinout & Package

TPS54331D is housed in an 8-pin SOIC package (4.90 mm × 6 mm) with exposed PowerPAD™ thermal pad on DDA variants; the D variant uses standard SOIC-8 without PowerPAD™. Thermal resistance R_θJA is 116.3°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with TPS54331D, TPS54231DR offers reduced current capacity and cost for lighter loads, while TPS54332DDA delivers higher output current, superior thermal handling, and faster switching-making it preferable for demanding industrial or automotive environments where layout area and thermal margin are constrained.

Availability

TPS54331D is available at Aetrix Electronics and suitable for industrial power supplies, consumer set-top boxes, car audio head units, and battery-powered peripherals requiring stable component supply across long production lifecycles.

Supply support for TPS54331D 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 headquartered in Dallas, Texas, specializing in analog and embedded processing technologies with broad industrial, automotive, and consumer product portfolios.

The TPS54331D belongs to TI's SWIFT™ family of DC-DC converters, designed specifically for high-efficiency, wide-input-voltage power conversion in space- and thermal-constrained applications where reliability and ease of design are critical.

FAQ

What is the minimum input voltage required for TPS54331D to operate?

The TPS54331D requires a minimum input voltage of 3.5 V for normal operation, as defined by its internal undervoltage lockout (UVLO) threshold. Below this level, the device ceases switching even if the EN pin is asserted. The datasheet specifies that operation below 3.5 V is not recommended, and the actual UVLO threshold may vary slightly with temperature and process, but remains tightly controlled around 3.5 V across the full –40°C to 150°C junction temperature range.

Does TPS54331D support adjustable output voltage, and what is the lowest achievable value?

Yes, TPS54331D supports fully adjustable output voltage using an external resistor divider on the VSENSE pin. The lowest achievable output voltage is 0.8 V, set by the internal voltage reference with ±2% initial accuracy. This reference is stable over temperature (±3.5% over –40°C to 150°C), enabling precise low-voltage regulation for modern microcontrollers and FPGAs requiring 0.8-V or 1.0-V core rails.

How does Eco-mode function in TPS54331D, and at what load does it activate?

Eco-mode in TPS54331D activates automatically when the peak inductor current drops below 160 mA (typical), causing the COMP pin voltage to clamp at 0.5 V and skip switching pulses. This reduces switching losses and maintains high efficiency (>85%) at light loads. Activation is cycle-by-cycle and load-dependent; average load current at entry varies with output filter characteristics, but the 160-mA threshold is measured at the inductor peak current-not output current.

What thermal protection features does TPS54331D include, and how does it recover?

TPS54331D incorporates thermal shutdown that triggers at 165°C junction temperature, halting all switching until the die cools below the trip point. Recovery is automatic: once junction temperature falls below 165°C, the device reinitiates the power-up sequence, including slow-start. No external reset is required. The SOIC-8 package has R_θJA = 116.3°C/W, so proper PCB copper pour under the GND pad is essential to avoid premature shutdown at full load.

Can TPS54331D be used with ceramic output capacitors, and what compensation considerations apply?

Yes, TPS54331D is optimized for ceramic output capacitors due to its internal slope compensation and transconductance error amplifier (92 μA/V). Compensation is implemented via an RC network between COMP and GND. Because ceramic capacitance degrades with DC bias, designers must derate nominal values-e.g., a 47-μF 6.3-V X5R capacitor may deliver only ~25 μF at 3.3-V bias-and verify stability using WEBENCH® or measured Bode plots rather than relying solely on datasheet tables.