UCC28711DR

UCC28711DR is TI’s high-efficiency offline flyback controller that implements primary-side regulation (PSR) for AC‑DC power supplies. It controls an external MOSFET and a flyback transformer to regulate output without opto-isolation, improving efficiency and reducing component count. Key features include valley switching to reduce switching losses, a wide input range (typical 85–265 VAC), current‑mode control with programmable peak current limit, a built‑in high‑voltage startup path, and protections such as overcurrent, overvoltage, short‑circuit, and thermal shutdown. The DR suffix denotes the packaging option (Tape‑and‑Reel) for the device. Typical applications: small to medium offline flyback supplies, phone chargers, USB adapters, and standby power. For exact electrical specs, timing, and application circuits, see the UCC28711 data sheet.

Key features of UCC28711DR (flyback controller):
- Primary‑side regulation (PSR): no optocoupler needed for isolated output regulation.
- Valley-switching, fixed-frequency operation to reduce switching losses and EMI.
- Universal input range with high‑voltage startup/bias circuitry from the bulk.
- Light-load efficiency with Eco-mode (burst/skip at low load).
- Robust protection: cycle‑by‑cycle current limit, overcurrent, overvoltage, undervoltage lockout, and thermal shutdown.
- Soft-start to limit inrush and output overshoot; prevents startup glitches.
- Minimal external parts required; suitable for compact offline adapters and chargers.
- 8‑pin package (DR variant) for small footprints.

UCC28711DR is an 8-pin device (SOIC-8). It is an offline flyback controller with primary-side regulation that drives an external high‑voltage MOSFET.
Pin functions (typical):
- DRAIN: HV drain to the external MOSFET/primary winding node
- GATE: drive output for the external MOSFET
- IS (or CS): current‑sense input
- FB: feedback input for regulation
- VCC: controller supply
- GND: ground
- RT/CT: oscillator timing network
- EN/SHDN (enable/shutdown): enables or disables the controller
Note: exact pin names may vary by package view, but these are the common functions for the 8-pin UCC28711DR.

- Manufacturer: Texas Instruments Incorporated (TI)
- Company type: American multinational semiconductor company that designs and manufactures analog, mixed-signal, and embedded processing ICs; headquarters in Dallas, Texas.

Applications for UCC28711DR (valley-switching, high-efficiency flyback controller) include:
- Off-line flyback switch-mode power supplies for consumer electronics
- Wall-wart and USB AC/DC adapters (phone/tablet chargers)
- Auxiliary/standby power supplies for TVs, set-top boxes, routers/modems, printers
- Low- to medium-power LED driver applications using flyback topology
- Small industrial control power supplies requiring high efficiency and tight regulation

It’s an 8-pin surface-mount package: D‑package SOIC (RoHS-compliant).