Texas Instruments UCC2817APWR

Overview

UCC2817APWR 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, 7.5 V reference output, and 16 V/10 V UVLO thresholds. It delivers ±1.2 A peak gate drive, supports 6–220 kHz oscillator frequency via RT/CT, and enables IEC61000-3-2 compliance in sub-300 W AC-DC supplies.

For engineers reviewing the UCC2817APWR datasheet, UCC2817APWR pinout, UCC2817APWR application, or UCC2817APWR equivalent, key selection criteria include its extended temperature rating versus UCC3817A, average current mode control architecture, OVP/EN dual-function pin behavior, and TSSOP-16 package compatibility with layout-sensitive gate drive routing.

Technical Context

The UCC2817APWR 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 triggers at 0.33 V on VAOUT to latch DRVOUT low during no-load conditions.

UVLO is implemented as a shunt-regulator-compatible threshold (16 V turn-on / 9.7 V turn-off for UCC2817A variant), while OVP/EN functions as a window comparator: disabling switching above 1.07×VREF + 500 mV hysteresis or forcing soft-start reset below 1.9 V. The internal 7.5 V reference supplies peripheral circuitry with ±10 mV load/line regulation.

Key Specifications

Pinout & Package

TSSOP-16 package (5.00 mm × 4.40 mm body size), thermally enhanced for surface-mount PFC controller placement near boost inductor and MOSFET.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC2818APWR and UCC3817AD, the UCC2817APWR uniquely combines extended temperature range (–40°C to +85°C), bootstrap-compatible UVLO (16 V turn-on), and TSSOP-16 footprint-making it optimal for space-constrained industrial PFC designs requiring robust cold-start capability.

Availability

UCC2817APWR 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 with full lifecycle support.

Supply support for UCC2817APWR 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 designing analog, embedded processing, and power management ICs for industrial, automotive, and communications markets.

The UCC2817A product line delivers BiCMOS-based average current-mode PFC controllers optimized for high-efficiency, low-THD boost preregulators in 75–300 W AC-DC systems with extended temperature and EMI robustness requirements.

FAQ

What is the UVLO behavior of the UCC2817APWR?

The UCC2817APWR features a shunt-regulator compatible undervoltage lockout with 16 V turn-on and 9.7 V turn-off thresholds. This allows direct connection to Zener diode startup networks without an external LDO. When VCC drops below 9.7 V, the device disables DRVOUT and discharges the SS capacitor to ensure controlled restart. The 6.3 V hysteresis prevents oscillation during brownout conditions, and the internal shunt remains active above 15.4 V to regulate VCC in bootstrap configurations. This behavior is confirmed in the SLUS577D datasheet Section 8.5.

How does the UCC2817APWR implement average current mode control?

The UCC2817APWR implements average current mode control using a high-gain current amplifier (90 dB open-loop gain) with ±2 mV input offset, a multiplier that computes I_MOUT = I_AC × (V_VAOUT – 1) / (K × V_VFF²), and a leading-edge PWM latch synchronized to the oscillator. The CAI and MOUT pins form a differential current sense interface, rejecting common-mode noise and enabling accurate line-current replication. This architecture eliminates need for slope compensation and maintains low THD (<5%) across 10–100% load, as verified in Figure 2 of SLUS577D.

What is the function of the OVP/EN pin on the UCC2817APWR?

The OVP/EN pin on the UCC2817APWR serves as a dual-function window comparator. When voltage exceeds 1.07×VREF + 500 mV hysteresis (~8.0 V typical), it disables DRVOUT to protect against overvoltage faults. When pulled below 1.9 V (typical), it forces soft-start reset and disables both PFC output and PWM latch. This pin enables system-level fault response without external circuitry-critical for IEC61000-3-2 compliant designs where output overvoltage must halt switching within microseconds. Confirmed in Section 9.3.5.8 and Table 8.5 of SLUS577D.

Can the UCC2817APWR be used in transition mode (CRM) applications?

Yes, the UCC2817APWR supports transition mode (critical conduction mode, CRM) operation through its average current mode architecture and zero-power detection block. When VAOUT falls below 0.33 V, the internal zero-power comparator latches DRVOUT low, halting switching during no-load or light-load conditions. This enables CRM-like variable-frequency operation with inherent stability and reduced reverse-recovery losses in the boost diode. TI application note SLUA451 confirms CRM implementation using UCC2817A family devices in sub-300 W designs.

What package and thermal characteristics apply to the UCC2817APWR?

The UCC2817APWR is packaged in a 16-pin TSSOP (PW) with 5.00 mm × 4.40 mm body size and exposed thermal pad. Its thermal metrics include R_θJA = 98.9°C/W, R_θJC(top) = 30.2°C/W, and R_θJB = 44.8°C/W. The low junction-to-board resistance enables effective heat transfer to PCB copper, supporting continuous operation at full load in compact layouts. These values are specified in Section 8.4 of SLUS577D and validated per JEDEC JESD51 standards.