Texas Instruments UCC28056BDBVT

Overview

UCC28056BDBVT 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 (OVP1/OVP2). It enables PFC-always-on architectures in desktop computing, LED drivers, and industrial power supplies.

For engineers reviewing the UCC28056BDBVT datasheet, UCC28056BDBVT pinout, UCC28056BDBVT application, or UCC28056BDBVT equivalent, key selection criteria include its 6-pin SOT-23 package, ultra-low startup current (<46 µA), wide VCC range (8.5–34 V), multi-mode TM/DCM control, and integrated thermal shutdown and cycle-by-cycle current limiting - all critical for green-power-compliant, cost-sensitive PFC designs.

Technical Context

The UCC28056BDBVT implements mixed-mode control: it operates in transition mode at full load and automatically transitions into DCM at reduced load, reducing switching frequency while maintaining low THD. Its ZCD/CS pin performs dual functions - current sensing during DRV high and drain voltage monitoring during DRV low - enabling line feed-forward, valley synchronization, and second-level OVP without auxiliary windings.

Burst mode is triggered below 15% load (UCC28056B-specific threshold), with soft-entry/exit periods minimizing audible noise. The error amplifier features non-linear transconductance (50 µS small-signal, 300 µS large-signal) for fast transient response without compromising input current distortion, and the COMP pin integrates internal clamping (5.5–5.71 V high, 0 V low) and discharge resistance (4.3–5.7 kΩ) during fault or stop states.

Key Specifications

Pinout & Package

SOT-23 (DBV) package, 2.90 mm × 1.6 mm body size, 6-pin surface-mount configuration with exposed pad not present. Thermal resistance R_ΘJA = 116.4 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC28056BDBVT, the UCC28056DBVT lacks OVP2 and offers lower burst sensitivity, making it less suitable for high-reliability systems; the UCC28056CDBVT adds earlier burst activation but sacrifices some light-load efficiency headroom - UCC28056BDBVT balances noise performance, protection, and efficiency for mainstream consumer/industrial use.

Availability

UCC28056BDBVT is available at Aetrix Electronics and suitable for desktop computing power supplies, LED driver front ends, industrial power tools chargers, and gaming console AC adapters requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for UCC28056BDBVT 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 and embedded processing technologies, with decades of expertise in power management ICs and energy-efficient system solutions.

The UCC28056 family is designed for cost-sensitive, high-efficiency AC-DC front-end applications - specifically targeting PFC+LLC architectures that must meet stringent global energy standards without auxiliary converters.

FAQ

What is the primary function of the UCC28056BDBVT in a power supply?

The UCC28056BDBVT is a transition-mode and discontinuous conduction mode power factor correction controller. Its primary function is to regulate the boost stage in single-phase AC-DC power supplies, ensuring near-unity power factor, low THD, and compliance with global energy standards such as DoE Level VI and Energy Star 6.1. In the UCC28056BDBVT, this is achieved through valley-synchronized MOSFET switching and multi-mode operation - all within a compact 6-pin SOT-23 package.

How does the UCC28056BDBVT differ from the base UCC28056DBVT?

The UCC28056BDBVT includes second-level output over-voltage protection (OVP2), improved ZCD noise immunity, and a burst mode activation threshold set at <15% load - versus <10% for UCC28056DBVT. These enhancements improve system robustness in electrically noisy environments and provide stronger bus voltage fault coverage. The UCC28056BDBVT retains identical pinout, package, and core control architecture as the base part, enabling drop-in replacement where enhanced protection is needed.

What is the significance of the ZCD/CS pin on the UCC28056BDBVT?

The ZCD/CS pin on the UCC28056BDBVT serves a dual role: during DRV high, it functions as a current sense input for cycle-by-cycle over-current protection; during DRV low, it monitors the MOSFET drain voltage waveform to enable zero-current detection, valley synchronization, line voltage feed-forward, and second-level OVP. This dual functionality eliminates the need for separate sense and timing circuits - directly reducing bill-of-materials and PCB area in PFC designs using the UCC28056BDBVT.

Can the UCC28056BDBVT operate without an auxiliary winding on the boost inductor?

Yes - the UCC28056BDBVT supports FET drain valley synchronized turn-on using only the main boost inductor's drain node, eliminating the need for an auxiliary winding. This capability is enabled by its integrated ZCD/CS circuitry, which accurately detects valley minima from the drain waveform. As a result, designs using the UCC28056BDBVT achieve lower system cost and higher reliability compared to controllers requiring auxiliary windings for timing - a key advantage confirmed in TI's official UCC28056BDBVT documentation.

What thermal protection features does the UCC28056BDBVT include?

The UCC28056BDBVT integrates over-temperature protection with a rising thermal shutdown threshold of 145°C (typ) and a falling hysteresis of 40°C - meaning it resumes operation only after junction temperature falls below 105°C. This thermal protection is active during switching and complements other safeguards including cycle-by-cycle current limiting, dual OVP, and UVLO. The device's SOT-23 package has a junction-to-ambient thermal resistance of 116.4°C/W, and its thermal shutdown behavior is fully characterized across −40°C to +125°C ambient conditions per the UCC28056BDBVT datasheet.