Texas Instruments UCC2817ADR

Overview

UCC2817ADR 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 12–18 V VCC supply, 16 V UVLO turn-on threshold, 7.5 V internal reference, and ±1.2 A peak gate drive capability. It enables IEC61000-3-2-compliant <300 W AC-DC supplies in PC power, lighting, and industrial systems.

For engineers reviewing the UCC2817ADR datasheet, UCC2817ADR pinout, UCC2817ADR application, or UCC2817ADR equivalent, key selection criteria include its extended temperature rating, average current mode control architecture, integrated OVP/EN window comparator, shunt-regulated VREF output, and compatibility with SOIC-16 packaging for high-density PFC stage design.

Technical Context

The UCC2817ADR implements average current-mode control using a high-gain current amplifier (90 dB open-loop gain, ±2 mV offset), multiplier-based feed-forward line regulation (VFF input, K = 1/V gain constant), and leading-edge PWM modulation synchronized to reduce bulk capacitor ripple. Its zero-power comparator monitors VAOUT to latch DRVOUT low below 0.33 V.

It integrates a precision 7.5 V reference (±1.5% accuracy, 20 mA sink/source), UVLO with 16 V/9.7 V hysteresis, and oscillator programmable via RT/CT (6–220 kHz range). The gate driver features 9 Ω pull-up and 4 Ω pull-down resistance, enabling robust MOSFET switching with controlled rise/fall times (25–50 ns).

Key Specifications

Pinout & Package

UCC2817ADR is housed in a 16-pin SOIC (D) package measuring 4.90 mm × 3.91 mm, with standard JEDEC MS-012AC footprint and 1.27 mm pitch. Thermal resistance R_θJA is 73.9°C/W, suitable for convection-cooled PFC boards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC2817ADR, UCC2818ADR offers lower UVLO for fixed-supply use but lacks bootstrap capability, while UC3854BDW provides higher power scalability at the cost of reduced integration and increased design effort.

Availability

UCC2817ADR is available at Aetrix Electronics and suitable for PC power supplies, industrial AC-DC converters, and LED driver power stages requiring stable component supply with full traceability and extended temperature qualification.

Supply support for UCC2817ADR 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 UCC2817ADR belongs to TI's UCCx81xA BiCMOS PFC controller family, engineered specifically for high-efficiency, low-distortion boost preregulators in sub-300 W IEC61000-3-2-compliant power supplies.

FAQ

What is the operating temperature range of the UCC2817ADR?

The UCC2817ADR is rated for operation from –40°C to +85°C, making it suitable for industrial and extended-environment applications. This distinguishes it from the UCC3817A (0°C to +70°C) and confirms its qualification for demanding thermal conditions in real-world PFC designs. The UCC2817ADR maintains full electrical specifications across this full range.

Does the UCC2817ADR include an internal voltage reference?

Yes, the UCC2817ADR integrates a precision 7.5 V reference (VREF pin) with ±1.5% accuracy and 20 mA sink/source capability. This reference is disabled below UVLO and requires a 0.1 µF ceramic bypass capacitor to GND for stability. It eliminates the need for an external reference in most PFC implementations, simplifying BOM and layout.

How does the UCC2817ADR implement overvoltage protection?

The UCC2817ADR uses the OVP/EN pin as a window comparator: it disables DRVOUT when the boost output exceeds 1.07×VREF + 500 mV hysteresis, and resets soft-start if the pin is pulled below 1.9 V. This dual-function pin provides both output overvoltage shutdown and enable/disable control without external comparators.

What is the purpose of the VFF pin on the UCC2817ADR?

The VFF (feed-forward voltage) pin accepts a scaled RMS representation of the AC input voltage, generated externally by mirroring half the IAC current into an RC filter. At low line, VFF is 1.4 V; at high line, it reaches 4.7 V. This enables improved line regulation and reduced input current distortion across universal input ranges.

Can the UCC2817ADR be used in critical conduction mode (CRM) designs?

No - the UCC2817ADR is designed exclusively for average current-mode control in continuous conduction mode (CCM) boost PFC topologies. It lacks the zero-crossing detection and variable-frequency control required for CRM. For CRM applications, TI recommends the UCC38050 or UCC3819 families instead of the UCC2817ADR.