Texas Instruments UCC2817DW

Overview

UCC2817DW from Texas Instruments is a BiCMOS active power factor correction (PFC) controller for boost preregulators, implementing average current mode control to achieve near-unity power factor and low line current distortion. It features 7.5-V reference output, 16-V/10-V UVLO thresholds, 6–220 kHz programmable oscillator, and integrated totem-pole gate driver delivering up to 1.2-A peak sink current - used in IEC61000-3-2-compliant sub-300-W AC/DC supplies.

For engineers reviewing the UCC2817DW datasheet, UCC2817DW pinout, UCC2817DW application, or UCC2817DW equivalent, key selection criteria include its extended temperature range (−40°C to +85°C), accurate 7.5-V reference with ±0.131-V max deviation over temperature, OVP/EN window comparator with 1.9-V enable threshold and 500-mV hysteresis, and soft-start current of −10-µA typical - critical for stable PFC startup and system-level compliance validation.

Technical Context

The UCC2817DW integrates an analog multiplier with three inputs (VAOUT, IAC, VFF) to generate a current-mode command signal (IMOUT) that shapes input current waveform proportionally to rectified line voltage. Its average current mode architecture uses CAI/MOUT differential sensing and CAOUT feedback to maintain low THD across universal input (85–265 VAC) while supporting leading-edge PWM modulation to reduce bulk capacitor ripple.

UVLO is implemented as a shunt-based circuit with 16-V turn-on/10-V turn-off hysteresis specific to UCC2817 variants, and zero-power detection monitors VAOUT to latch DRVOUT low when output falls below 0.33-V threshold - enabling lossless disable during standby. The internal 7.5-V reference powers external bias networks and supports 20-mA load capability with <10-mV line/load regulation.

Key Specifications

Pinout & Package

UCC2817DW is housed in a 16-pin SOIC (DW) package measuring 7.5 mm × 10.3 mm, with standard 1.27-mm pitch and gull-wing leads suitable for automated PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC2817DW, UCC2818DW offers lower UVLO turn-on voltage for earlier startup but sacrifices high-line robustness, while ICE3PCS01G trades design flexibility and precision for integration and BOM reduction - making UCC2817DW optimal for industrial-grade, wide-input, high-THD-performance PFC stages.

Availability

UCC2817DW is available at Aetrix Electronics and suitable for PC power supplies, industrial AC/DC adapters, LED driver front-ends, and consumer electronics power stages requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for UCC2817DW 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 technologies, with decades of expertise in power conversion IC design and manufacturing.

The UCC2817DW belongs to TI's BiCMOS PFC controller product line, engineered specifically for high-efficiency, low-distortion active power factor correction in universal-input AC/DC systems up to 300 W.

FAQ

What is the UVLO behavior of the UCC2817DW?

The UCC2817DW implements a shunt-based undervoltage lockout with 16-V turn-on and 10-V turn-off thresholds, providing 6.3-V hysteresis. This ensures clean startup above nominal line and reliable dropout recovery during brownouts. Unlike the UCC2818DW, the UCC2817DW's higher UVLO is optimized for robust operation across universal AC inputs - critical for industrial and high-reliability UCC2817DW deployments.

How does the UCC2817DW achieve near-unity power factor?

The UCC2817DW achieves near-unity power factor using average current mode control with a three-input analog multiplier (VAOUT, IAC, VFF) that generates IMOUT to command the PWM duty cycle. This forces input current to track rectified line voltage waveform with <5% THD. The UCC2817DW's ±2-mV current amplifier offset and leading-edge modulation further reduce distortion - especially at light loads - ensuring IEC61000-3-2 compliance in UCC2817DW-based designs.

Can the UCC2817DW drive a MOSFET directly?

Yes, the UCC2817DW integrates a totem-pole gate driver on DRVOUT capable of 1.2-A peak sink and 0.9-A peak source current, with 5–12-Ω pullup/pulldown resistance. However, a series gate resistor (≥11 Ω at 18 V) is mandatory to damp ringing and prevent shoot-through. This direct-drive capability eliminates external drivers in most sub-300-W UCC2817DW applications, reducing BOM count and layout area.

What is the role of the VFF pin on the UCC2817DW?

The VFF pin on the UCC2817DW outputs a feed-forward RMS voltage derived from half the IAC current, filtered externally to represent input line voltage magnitude. At low line (e.g., 85 VAC), VFF = 1.4 V; at high line (265 VAC), VFF ≈ 4.7 V. This signal scales the multiplier gain to maintain constant power delivery - a core function enabling UCC2817DW's wide-input operation and tight regulation across 85–265 VAC.

Does the UCC2817DW support soft-start, and how is it implemented?

Yes, the UCC2817DW implements soft-start via the SS pin, which charges an external capacitor with a −10-μA current source. This voltage ramps VAOUT during startup, gradually increasing PWM duty cycle to limit inrush current and prevent overcurrent faults. If VCC drops below UVLO, OVP/EN pulls low and SS discharges rapidly - ensuring safe UCC2817DW restart after brownout events.