Texas Instruments UCC28056CDBVT

Overview

UCC28056CDBVT from Texas Instruments is a 6-pin SOT-23 transition-mode (TM) and discontinuous conduction mode (DCM) power factor correction (PFC) controller for single-phase AC-DC front ends. It delivers <80 mW no-load input power at 230 VAC, supports up to 300 W PFC stages, and features valley-synchronized FET turn-on, burst-mode operation with soft-entry/exit, and dual output over-voltage protection. It enables PFC-always-on architectures in desktop computing, LED drivers, and industrial power supplies.

For engineers reviewing the UCC28056CDBVT datasheet, UCC28056CDBVT pinout, UCC28056CDBVT application, or UCC28056CDBVT equivalent, key selection criteria include its ultra-low standby power capability, multi-mode TM/DCM control logic, ZCD-based valley detection timing, integrated thermal shutdown, and compatibility with LLC controllers like UCC256403/4 for complete high-efficiency offline systems.

Technical Context

The UCC28056CDBVT implements mixed-mode control: it operates in transition mode at full load and automatically transitions into DCM at reduced load to lower switching frequency and improve light-load efficiency. Its ZCD/CS pin performs dual functions-current sensing during DRV high and drain voltage monitoring during DRV low-to enable line feed-forward, brown-in detection, valley synchronization, and second-level OVP.

Burst mode is triggered below 10% load (UCC28056C-specific threshold), with soft-entry/exit periods minimizing audible noise. The error amplifier features nonlinear transconductance gain (50 µS small-signal, 300 µS large-signal) and fast transient response without compromising input current THD. Internal protections include cycle-by-cycle current limit, dual OVP (VOSNS and OVP2), and thermal shutdown with 40°C hysteresis.

Key Specifications

Pinout & Package

SOT-23 (DBV) package, 2.90 mm × 1.6 mm body size, 6-pin surface-mount configuration with GND on Pin 4 for optimal power stage grounding.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PFC controller applications.

Compared with UCC28056BDBVT and UCC28056ADBVT, the UCC28056CDBVT offers the lowest burst-mode activation point (<10% load) and highest noise immunity - making it optimal for silent, high-reliability applications like medical and premium consumer power supplies where layout margin is constrained.

Availability

UCC28056CDBVT is available at Aetrix Electronics and suitable for desktop computing power supplies, LED driver front ends, industrial AC adapters, and e-bike charger designs requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for UCC28056CDBVT 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 delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The UCC28056 family is designed specifically for cost-sensitive, high-efficiency single-phase PFC applications demanding ultra-low standby power, seamless TM/DCM transition, and robust operation in compact SOT-23 packages.

FAQ

What is the primary function of the UCC28056CDBVT in a power supply system?

The UCC28056CDBVT is a transition-mode and discontinuous conduction mode power factor correction controller that regulates the boost stage in AC-DC power supplies. It ensures sinusoidal input current, near-unity power factor, and stable 400 VDC output bus. In systems using UCC28056CDBVT with UCC256403/4 LLC controllers, the UCC28056CDBVT enables PFC-always-on operation achieving <80 mW standby power without auxiliary converters.

How does the UCC28056CDBVT achieve ultra-low no-load power consumption?

The UCC28056CDBVT achieves <80 mW no-load input power through ultra-low startup current (<46 µA), burst-mode operation with soft-entry/exit, and intelligent multi-mode control that reduces switching frequency at light loads. Its enhanced ZCD noise immunity and valley-synchronized turn-on eliminate auxiliary windings and reduce gate drive losses - all contributing to the UCC28056CDBVT's compliance with stringent green power standards including DoE Level VI and Energy Star 6.1.

What distinguishes the UCC28056CDBVT from the base UCC28056 variant?

The UCC28056CDBVT includes OVP2 protection, enhanced ZCD noise immunity, and a <10% load burst-mode threshold - differentiating it from the base UCC28056, which lacks OVP2 and uses basic noise immunity with a <10% threshold. These enhancements make the UCC28056CDBVT more robust in electrically noisy environments and better suited for silent operation in consumer and medical applications than the original UCC28056.

Can the UCC28056CDBVT be used with LLC resonant controllers?

Yes, the UCC28056CDBVT is explicitly designed to pair with TI's UCC256403/4 LLC controllers. When combined, they form a complete high-efficiency PFC+LLC offline power supply capable of <80 mW system standby power. The UCC28056CDBVT's valley-synchronized gate drive, precise OVP thresholds, and burst-mode timing align with UCC256403/4 requirements - enabling PFC-always-on architecture without auxiliary converters.

What thermal protection features does the UCC28056CDBVT provide?

The UCC28056CDBVT integrates thermal shutdown with a rising threshold of 145°C and falling threshold of 105°C (40°C hysteresis). This protects the IC during sustained overload, poor heatsinking, or ambient temperature excursions. The SOT-23 package has a junction-to-board thermal resistance of 36.1°C/W, and the UCC28056CDBVT's low operating current (2.2 mA typical) minimizes self-heating - ensuring reliable operation up to +125°C ambient.