Texas Instruments UCC2818PW

Overview

UCC2818PW 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 operates across universal AC input (85–265 VAC), features 10.5 V/10 V UVLO thresholds, 7.5 V reference output, and drives external MOSFETs via integrated totem-pole gate driver DRVOUT - used in sub-300 W IEC 61000-3-2-compliant PC and industrial power supplies.

For engineers reviewing the UCC2818PW datasheet, UCC2818PW pinout, UCC2818PW application, or UCC2818PW equivalent, key selection considerations include its 10.5 V turn-on UVLO, 7.5 V precision reference, soft-start (SS) pin behavior during VCC dropout, and compatibility with leading-edge modulation for reduced bulk capacitor ripple in two-stage AC-DC systems.

Technical Context

The UCC2818PW employs average current mode control with a high-bandwidth current amplifier (CAI/MOUT inputs, CAOUT output) and a three-input analog multiplier (IAC, VFF, VAOUT) to shape input current waveform proportionally to rectified line voltage. Its internal oscillator (RT/CT programmable, f ≈ 0.6/(RT×CT)) supports 6–220 kHz operation, and zero-power detection (0.33 V threshold on VAOUT) disables switching under no-load conditions.

It integrates a 7.5 V ±1.5% voltage reference (VREF), overvoltage protection (OVP/EN window comparator with 1.9 V enable threshold and 500 mV hysteresis), and peak current limiting (PKLMT referenced to 0 V). The device is rated for −40°C to +85°C operation and uses BiCMOS process for low start-up current (150 μA typical) and low power dissipation.

Key Specifications

Pinout & Package

UCC2818PW is housed in a 16-pin TSSOP (PW) package measuring 5.0 mm × 4.4 mm × 1.2 mm, with exposed thermal pad for enhanced heat dissipation in surface-mount applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power factor correction controller applications.

Compared with UCC2817PW and FAN7930C, the UCC2818PW uniquely combines −40°C to +85°C operation, precise 10.5 V/10 V UVLO hysteresis for robust universal input startup, and integrated zero-power detection - making it optimal for industrial and globally deployed AC-DC systems requiring reliability across voltage and temperature extremes.

Availability

UCC2818PW is available at Aetrix Electronics and suitable for PC power supplies, industrial AC-DC converters, LED driver front-ends, and consumer electronics adapters requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for UCC2818PW 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 specializing in analog and embedded processing technologies, with decades of leadership in power management IC design and manufacturing.

The UCC2818PW 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 power supplies up to 300 W.

FAQ

What is the UVLO threshold behavior of the UCC2818PW?

The UCC2818PW features an undervoltage lockout with 10.5 V turn-on and 10 V turn-off thresholds, providing 0.5 V hysteresis. This ensures reliable startup after input stabilization and prevents erratic operation during brownout conditions. The UCC2818PW remains disabled until VCC exceeds 10.5 V, then sustains operation down to 10 V before disabling again - critical for consistent performance across universal AC line ranges.

How does the UCC2818PW implement zero-power detection?

The UCC2818PW monitors the voltage error amplifier output (VAOUT) and triggers zero-power mode when VAOUT falls below 0.33 V. This causes the internal logic to disable the DRVOUT gate driver, halting switching and reducing no-load input power to minimal levels. This feature is integral to meeting stringent ENERGY STAR and EU CoC standby loss requirements without external circuitry.

Can the UCC2818PW be used in discontinuous conduction mode (DCM)?

Yes - the UCC2818PW supports both continuous conduction mode (CCM) and transition mode (critical conduction mode, CRM), but not pure DCM. Its average current mode architecture and internal PWM latch are optimized for CCM and boundary-mode operation in boost PFC topologies. For true DCM PFC, a dedicated DCM controller such as the UCC28051 would be more appropriate than the UCC2818PW.

What is the purpose of the MOUT pin on the UCC2818PW?

The MOUT pin on the UCC2818PW serves a dual role: it is both the output node of the analog multiplier and the inverting input of the current amplifier. This high-impedance connection enables differential current sensing between CAI and MOUT, improving noise immunity and supporting leading-edge modulation. The multiplier output current is limited to ±2×IAC, ensuring predictable scaling across line and load conditions.

Does the UCC2818PW require external compensation components?

Yes - the UCC2818PW requires external compensation components between CAOUT and MOUT (current loop) and between VSENSE and VAOUT (voltage loop). These networks stabilize the dual-loop control system; typical configurations use RC networks with values selected based on output capacitance, inductor value, and desired phase margin. TI's SLUS395K datasheet provides design equations and example values for standard 200–300 W applications.