Texas Instruments UCC2818AN

Overview

UCC2818AN from Texas Instruments is a BiCMOS average current-mode power factor correction (PFC) controller for boost preregulators, operating across –40°C to 85°C with 10.2 V UVLO turn-on threshold, 7.5 V reference output, and ±1.2 A peak gate drive capability. It enables IEC 61000-3-2 compliant <300 W supplies in PC power, lighting, and industrial AC/DC systems.

For engineers reviewing the UCC2818AN datasheet, UCC2818AN pinout, UCC2818AN application, or UCC2818AN equivalent, this page delivers verified technical context, real-world PFC design parameters, package-specific layout guidance, and validated alternative options - all grounded in TI's SLUS577D production data sheet.

Technical Context

The UCC2818AN implements average current mode control using a high-gain current amplifier (90 dB open-loop gain, ±2 mV offset), a precision 7.5 V reference (±1.5% over temperature), and a three-input analog multiplier (IAC, VFF, VAOUT) to generate line-synchronized duty cycle commands. Its leading-edge PWM modulation reduces bulk capacitor ripple current.

It integrates UVLO with 10.2 V turn-on/9.7 V turn-off hysteresis, overvoltage protection (OVP/EN pin with 1.9 V enable threshold and 500 mV hysteresis), soft-start via SS pin (–10 µA charge current), and zero-power detection (0.33 V comparator threshold on VAOUT). The oscillator frequency is set by RT and CT, supporting 6–220 kHz operation.

Key Specifications

Pinout & Package

UCC2818AN is supplied in a 16-pin PDIP (N) package measuring 19.30 mm × 6.35 mm, optimized for through-hole mounting and thermal dissipation in offline PFC stages.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC2818AN, UCC2817AN offers higher UVLO for noisy VCC rails but identical PFC performance, while UC3854BDW demands more external components and lacks integrated OVP - making UCC2818AN optimal for new compact, cost-sensitive, and safety-compliant <300 W designs.

Availability

UCC2818AN is available at Aetrix Electronics and suitable for PC power supplies, LED lighting drivers, and industrial AC/DC converters requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for UCC2818AN 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 power management solutions with emphasis on reliability, efficiency, and system integration.

The UCC2818AN belongs to TI's UCCx81xA BiCMOS PFC controller family, designed specifically for cost-effective, high-efficiency active power factor correction in sub-300 W offline power supplies meeting IEC 61000-3-2 standards.

FAQ

What is the UVLO threshold for UCC2818AN?

The UCC2818AN features an undervoltage lockout (UVLO) with a turn-on threshold of 10.2 V and turn-off threshold of 9.7 V, providing 0.5 V hysteresis to prevent oscillation during brownout conditions. This ensures the UCC2818AN remains disabled until VCC stabilizes above 10.2 V, protecting the PFC stage from unstable operation during power-up or line dips.

Does UCC2818AN support both CCM and CRM PFC topologies?

The UCC2818AN is optimized for continuous conduction mode (CCM) average current mode control, as confirmed by its internal architecture - including the current amplifier, multiplier, and PWM latch. While it can be adapted for critical conduction mode (CRM) with external modifications, TI's documentation and application circuits (e.g., Figure 5 in SLUS577D) specify CCM operation for UCC2818AN, and CRM is explicitly associated with UCC38050/1 in TI's device comparison tables.

What is the maximum gate drive current capability of UCC2818AN?

The UCC2818AN delivers ±1.2 A peak source/sink current on the DRVOUT pin, with typical pull-up resistance of 9 Ω and pull-down resistance of 4 Ω. This allows direct driving of medium-power MOSFETs (e.g., 500 V, 20 A) without external buffers, reducing component count and PCB area in space-constrained PFC designs using the UCC2818AN.

How does the OVP/EN pin function on UCC2818AN?

The OVP/EN pin on UCC2818AN is a dual-function window comparator: it disables DRVOUT when the boost output exceeds a programmed overvoltage threshold (reference = VREF + 0.5 V, hysteresis = 500 mV), and forces full shutdown when pulled below 1.9 V (typical), resetting soft-start. This dual behavior makes the UCC2818AN suitable for systems requiring both output overvoltage protection and controlled enable sequencing.

Is UCC2818AN pin-compatible with UCC2817AN?

Yes, UCC2818AN is fully pin-compatible with UCC2817AN - both use identical 16-pin PDIP (N) packaging and share identical pin functions, electrical characteristics, and block diagrams. The only functional difference is UVLO threshold (10.2 V for UCC2818AN vs. 16 V for UCC2817AN), allowing direct substitution where the lower threshold meets system requirements.