Texas Instruments UCC28051DG4

Overview

UCC28051DG4 from Texas Instruments is a transition-mode (boundary-conduction mode) power factor correction (PFC) controller for low-to-medium power AC-DC supplies, featuring 12.5 V UVLO turn-on threshold, ±750-mA peak gate drive, and 2.5 V internal reference voltage. It enables IEC 61000-3-2-compliant boost preregulators in two-stage converters where downstream PWM control governs PFC activation.

For engineers reviewing the UCC28051DG4 datasheet, UCC28051DG4 pinout, UCC28051DG4 application, or UCC28051DG4 equivalent, key selection criteria include its narrow 2.8 V UVLO hysteresis, 300 µA typical g_M amplifier source current for controlled start-up, zero-power detect for light-load OVP prevention, and SOIC-8 package compatibility with industry-standard PFC controller footprints.

Technical Context

The UCC28051DG4 implements transition-mode control using zero-current detection (ZCD pin) to trigger switch turn-on and current-sense (CS pin) comparison to terminate conduction-enabling self-oscillating variable-frequency operation without external timing components. Its transconductance error amplifier (90 µS typ.) drives a multiplier with VMULTIN and COMP inputs to generate a line-shaped current command.

Core protection logic includes enable/disable via VO_SNS voltage threshold (0.23 V typ.), overvoltage protection (OVP) at VREF + 0.18 V, and zero-power detection activated when COMP falls below 2.3 V-ensuring shutdown during pre-charge or open-feedback faults. The device operates across –40°C to +105°C junction temperature with 4–6 mA typical supply current in active mode.

Key Specifications

Pinout & Package

UCC28051DG4 is housed in an 8-pin SOIC (D) package measuring 3.91 mm × 4.90 mm, optimized for surface-mount assembly and thermal performance (R_θJA = 113.6°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC28051DG4, UCC28050DG4 offers faster start-up and stronger transient drive but lacks tight UVLO control for PWM coordination, while ICE2PCS01G trades CRM simplicity for CCM efficiency and higher integration-making UCC28051DG4 optimal for cost-sensitive, two-stage <300 W designs requiring light-load safety and layout simplicity.

Availability

UCC28051DG4 is available at Aetrix Electronics and suitable for AC adapters, two-stage desktop SMPS, LED lighting ballasts, and motor drive pre-regulators requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for UCC28051DG4 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets-with over 50 years of power management innovation.

The UCC2805x family was designed specifically for cost-effective, IEC 61000-3-2-compliant transition-mode PFC in low-to-medium power AC-DC conversion-emphasizing ease of implementation, protection integration, and thermal robustness in SOIC packaging.

FAQ

What is the UVLO behavior of the UCC28051DG4 and how does it differ from UCC28050DG4?

The UCC28051DG4 features a 12.5 V turn-on threshold and 9.7 V turn-off threshold, yielding a narrow 2.8 V UVLO hysteresis-enabling precise coordination with downstream PWM controllers in two-stage power supplies. In contrast, the UCC28050DG4 uses a 15.8 V turn-on and 9.7 V turn-off (6.3 V hysteresis) for faster start-up with smaller VCC capacitors. This difference makes UCC28051DG4 ideal for systems where PFC activation must be gated by secondary-stage readiness, while UCC28050DG4 suits standalone applications like electronic ballasts.

How does the zero-power detect function work in the UCC28051DG4?

The UCC28051DG4 monitors the COMP pin voltage and activates zero-power detect when it falls below 2.3 V-latching the gate driver low to prevent output overvoltage during no-load or light-load conditions. This function works independently of OVP and relies on the transconductance amplifier's slew-enhanced behavior: during overvoltage events, the amplifier rapidly pulls COMP low, triggering shutdown before bus voltage exceeds VREF + 0.18 V. The 2.3 V threshold is ensured by design and provides fail-safe protection even if feedback components drift.

Can the UCC28051DG4 drive a MOSFET directly, and what are the gate drive limitations?

Yes, the UCC28051DG4 integrates a ±750-mA peak totem-pole gate driver (Pin 7, DRV) capable of directly driving medium-size MOSFETs in sub-300 W applications. Rise/fall times are ≤75 ns with 1 nF load and 10 Ω series resistance. However, for MOSFETs with >2 nF total gate charge or requiring >1 A peak current, an external driver is recommended. The driver is disabled during UVLO, OVP, enable disable, or zero-power detect-ensuring safe, fault-protected operation without external logic.

What is the role of the MULTIN pin and how should it be interfaced?

The MULTIN pin (Pin 3) accepts a scaled version of the rectified AC line voltage (0–2.5 V range), serving as one input to the internal analog multiplier that shapes the current command. A resistor divider from the boost input-designed to deliver ≤2.5 V at maximum line-is required. The pin includes a built-in 75 mV offset to improve zero-crossing fidelity and reduce THD. Input bias current is ≤1 µA, allowing high-impedance dividers; external filtering may be added if EMI coupling is observed, but the internal noise rejection minimizes need for RC networks.

Does the UCC28051DG4 support both continuous and transition-mode PFC operation?

No, the UCC28051DG4 is exclusively a transition-mode (boundary-conduction mode or CRM) controller. It relies on zero-current detection (ZCD pin) to initiate each switching cycle and current-sense comparison (CS pin) to terminate it-producing variable-frequency operation inherently tied to input voltage and load. It does not support fixed-frequency continuous conduction mode (CCM); for CCM designs, TI's UCC28070 or Infineon's ICE2PCS01G would be appropriate alternatives.