Texas Instruments UCC3819D

Overview

UCC3819D from Texas Instruments is a BiCMOS active power factor correction (PFC) controller for boost preregulators, implementing average current mode control with leading-edge modulation, 10.8–17-V VCC operation, 150-µA typical start-up current, and programmable output voltage via the VAI pin. It enables near-unity power factor in universal-input AC-DC front-ends for industrial SMPS and server power supplies.

For engineers reviewing the UCC3819D datasheet, UCC3819D pinout, UCC3819D application, or UCC3819D equivalent, key selection criteria include its tracking boost capability (VAI pin), over-voltage protection window on OVP/EN, 7.5-V internal reference accuracy (±12.5 mV), and 85–115 kHz oscillator initial accuracy at 25°C.

Technical Context

The UCC3819D integrates a high-gain voltage error amplifier (50–90 dB open-loop gain), a wide-bandwidth current amplifier (2.5 MHz GBW), and an analog multiplier with programmable gain constant (0.5–1.5 V⁻¹) to shape line current in real time. Its zero-power comparator (0.20–0.50 V threshold on VAOUT) enables precise low-power detection during light-load conditions.

It employs feed-forward line regulation via VFF (mirrored IAC current), supports dynamic output voltage scaling through VAI–VFF connection, and features shunt UVLO detection (10.2 V turn-on, 9.7 V turn-off) with 0.5 V hysteresis. The gate driver delivers 0.2 A continuous / 1.2 A peak current with 25 ns rise and 10 ns fall times into 1 nF load.

Key Specifications

Pinout & Package

UCC3819D is housed in a 16-pin SOIC (D) package with standard 1.27-mm pitch, JEDEC MS-012AC compliant, RoHS-compliant NIPDAU lead finish, and MSL Level-1 rating (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC2819D, the UCC3819D trades extended temperature support for lower cost and qualification scope, while compared with L6562A it adds VAI-based tracking, integrated VREF, and superior feed-forward line regulation-making it optimal for high-efficiency, dynamically scaled PFC stages.

Availability

UCC3819D is available at Aetrix Electronics and suitable for server power supplies, industrial AC-DC rectifiers, medical imaging systems, and telecom rectifier modules requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for UCC3819D 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, embedded processing, and power management ICs, with decades of expertise in power conversion and energy-efficient system design.

The UCC3819D belongs to TI's UCC28xx/UCC38xx family of active PFC controllers, designed specifically for high-performance, high-efficiency AC-DC front-end regulation in industrial, computing, and communications equipment.

FAQ

What is the operating temperature range for the UCC3819D?

The UCC3819D is specified for operation from 0°C to 70°C ambient temperature. This range is validated per its electrical characteristics table in SLUS482B, where all parameters (e.g., VREF accuracy, oscillator frequency, UVLO thresholds) are guaranteed across this interval. For extended temperature applications (−40°C to 85°C), the pin-compatible UCC2819D should be selected instead. The UCC3819D's SOIC (D) package has MSL Level-1 rating, supporting standard reflow profiles.

How does the VAI pin enable tracking boost functionality in the UCC3819D?

The VAI pin on the UCC3819D is the non-inverting input of the internal voltage error amplifier, brought out externally to allow dynamic programming of the boost output voltage. When connected to the VFF pin-which mirrors the RMS line voltage-the UCC3819D scales its output voltage proportionally (e.g., 300 V at 115 VAC, 400 V at 230 VAC). This reduces inductor size, MOSFET conduction losses, and component stress at low line, as confirmed in the UCC3819D application note Figure 1 and tracking boost implementation section.

What is the purpose of the OVP/EN pin on the UCC3819D?

The OVP/EN pin on the UCC3819D serves dual functions: it acts as a window comparator for overvoltage protection (triggering shutdown when voltage exceeds VREF + 0.48–0.52 V) and as an enable input (disabling DRVOUT when pulled below 1.9 V). This dual role allows a single external resistor divider to monitor boost output voltage and provide fail-safe shutdown, eliminating need for separate supervisor ICs. The hysteresis (300–600 mV) prevents chatter during transient overvoltage events.

Can the UCC3819D be used in discontinuous conduction mode (DCM) PFC applications?

No, the UCC3819D is explicitly designed for continuous conduction mode (CCM) average current mode control in boost preregulators, as stated in its datasheet description and block diagram. Its current amplifier, multiplier, and PWM latch architecture assume CCM operation with sensed inductor current. DCM operation would violate the control loop assumptions, resulting in unstable regulation and distorted line current. For DCM PFC, TI recommends alternatives such as the UCC28019 or L6562 series.

What are the absolute maximum ratings for the DRVOUT pin on the UCC3819D?

The DRVOUT pin on the UCC3819D has an absolute maximum rating of 1.2 A peak source/sink current and a maximum negative voltage of −0.5 V. Continuous drive current is rated at 0.2 A. Exceeding these values risks permanent damage. The datasheet specifies 25 ns rise time and 10 ns fall time into a 1 nF load with 10 Ω series resistance, and recommends using a gate resistor to prevent overshoot-especially critical given DRVOUT's totem-pole output structure and capacitive gate loads.