Texas Instruments TPS54628DDA

Overview

TPS54628DDA from Texas Instruments is a 6-A synchronous step-down DC/DC converter with D-CAP2™ control mode, operating from 4.5 V to 18 V input and delivering adjustable output voltage from 0.76 V to 5.5 V. It integrates 36 mΩ high-side and 28 mΩ low-side N-channel MOSFETs, supports 650-kHz pseudo-fixed switching frequency, and features Eco-Mode™ for high light-load efficiency in digital TV and STB power rails.

For engineers reviewing the TPS54628DDA datasheet, TPS54628DDA pinout, TPS54628DDA application, or TPS54628DDA equivalent, key selection considerations include its adaptive on-time control architecture, SO PowerPAD (8) thermal performance (R_θJA = 43.5°C/W), cycle-by-cycle overcurrent protection, prebiased soft-start capability, and compatibility with ceramic and low-ESR polymer output capacitors.

Technical Context

The TPS54628DDA implements D-CAP2™ adaptive on-time control, eliminating external compensation while enabling fast transient response via internal ramp injection and pseudo-fixed-frequency operation. Its control loop dynamically transitions between PWM mode at heavy loads and Eco-Mode™ discontinuous conduction at light loads using valley-current detection and zero-current sensing.

It integrates dual N-channel MOSFETs with matched R_DS(on) (36 mΩ HS / 28 mΩ LS), uses VREG5 as an internal 5.5-V LDO supply for gate drive, and incorporates non-latching protections including thermal shutdown (165°C), output overvoltage (125% V_OUT), hiccup-mode undervoltage (65% V_OUT), and UVLO (3.75 V typical on VREG5).

Key Specifications

Pinout & Package

TPS54628DDA is housed in an 8-pin SO PowerPAD (DDA) package (4.89 mm × 3.90 mm) with an exposed thermal pad that must be soldered to a GND plane for thermal management and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck converter applications.

Compared with TPS54628DDA, TPS54627DDA offers identical functionality at reduced current rating for cost-sensitive designs, while MP2315DJ-LF-Z trades Eco-Mode™ and prebias support for wider VIN range-making TPS54628DDA optimal for 12 V-based consumer electronics demanding high light-load efficiency and robust startup behavior.

Availability

TPS54628DDA is available at Aetrix Electronics and suitable for digital television power supplies, high-definition Blu-ray players, networking home terminals, and digital set-top boxes requiring stable component supply across production lifecycles.

Supply support for TPS54628DDA 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, designing and manufacturing analog and embedded processing solutions for industrial, automotive, and consumer markets.

The TPS54628DDA belongs to TI's D-CAP2™ synchronous buck converter product line, engineered specifically for high-efficiency, low-component-count power conversion in space-constrained consumer electronics with stringent light-load efficiency requirements.

FAQ

What is the recommended input capacitor configuration for TPS54628DDA?

TI recommends a minimum 10 µF ceramic input capacitor placed close to the VIN and GND pins of the TPS54628DDA, plus an optional 0.1 µF ceramic capacitor directly from VIN to GND for high-frequency noise suppression. The capacitor voltage rating must exceed the maximum input voltage, and placement must minimize loop area to reduce EMI and improve stability. This configuration ensures adequate charge reservoir and low-impedance path during high di/dt switching events.

Does TPS54628DDA support prebiased output startup?

Yes, the TPS54628DDA supports prebiased soft start through proprietary circuitry that prevents current sinking from an already-powered output. When enabled, it gradually increases low-side FET on-time cycle-by-cycle until reaching normal regulation, avoiding output voltage collapse. This feature is active by default and requires no external components-critical for hot-swap and multi-rail sequencing applications where downstream circuits may be powered before the TPS54628DDA enables.

What is the thermal pad connection requirement for TPS54628DDA?

The exposed thermal pad on the TPS54628DDA SO PowerPAD package must be soldered to a solid GND copper plane on the PCB to achieve rated 6-A performance and thermal reliability. TI specifies this connection as mandatory-not optional-for thermal dissipation (R_θJB = 25.6°C/W) and electrical integrity. Failure to solder the pad results in junction temperature rise exceeding safe limits and potential thermal shutdown under load.

How does Eco-Mode™ improve light-load efficiency in TPS54628DDA?

Eco-Mode™ in the TPS54628DDA improves light-load efficiency by automatically skipping switching cycles when output current falls below ~300 mA, reducing switching losses and quiescent current to <10 µA. Unlike forced-PWM operation, this pulse-skipping behavior maintains high efficiency (>85%) down to 10 mA load while preserving output regulation accuracy and minimizing audible noise-ideal for always-on consumer devices like STBs and media players.

Can TPS54628DDA operate with ceramic output capacitors only?

Yes, the TPS54628DDA is explicitly designed to operate stably with ceramic output capacitors, thanks to its D-CAP2™ control architecture and internal ramp compensation. TI recommends 22 µF to 68 µF total ceramic capacitance (e.g., two 22 µF X5R 0805s) with ≤5 mΩ ESR. No additional ESR or tantalum/polymer capacitors are required-enabling smaller footprint, longer lifetime, and lower cost versus traditional buck controllers needing external compensation.