Constant-voltage, constant-current PWM with PSR, valley switching, NTC option, and 0-mV cable comp.


Product details


Control mode Primary-side regulation Frequency (Max) (kHz) 100 UVLO thresholds on/off (V) 21/8 Duty cycle (Max) (%) 99 Features PSR, DCM, HV Start-up, Green Mode, Input Line Monitor, Leading Edge Blanking, Light Load Efficiency, Low Power, Soft Start Operating temperature range (C) -40 to 125 Rating Catalog Device type Controllers Topology Buck, Flyback open-in-new Find other Flyback controllers

Package | Pins | Size

SOIC (D) 7 29 mm² 4.9 x 6 open-in-new Find other Flyback controllers


  • < 10-mW No-Load Power
  • Primary-Side Regulation (PSR) Eliminates Opto-Coupler
  • ±5% Voltage and Current Regulation Across Line and Load
  • 700-V Start-Up Switch
  • 100-kHz Maximum Switching Frequency Enables High-Power Density Charger Designs
  • Resonant Valley-Switching Operation for Highest Overall Efficiency
  • Frequency Jitter to Ease EMI Compliance
  • Wide VDD Range Allows Small Bias Capacitor
  • Clamped Gate-Drive Output for MOSFET
  • Overvoltage, Low-Line, and Overcurrent Protection Functions
  • Programmable Cable Compensation (UCC28710)
  • NTC Resistor Interface (UCC28711, UCC28712 and UCC28713) with Fixed Cable Compensation Options
  • SOIC-7 Package
  • Create a Custom Design Using the UCC28710 With the WEBENCH® Power Designer
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The UCC2871x family of flyback power supply controllers provides isolated-output Constant-Voltage (CV) and Constant-Current (CC) output regulation without the use of an optical coupler. The devices process information from the primary power switch and an auxiliary flyback winding for precise control of output voltage and current.

An internal 700-V start-up switch, dynamically-controlled operating states and a tailored modulation profile support ultra-low standby power without sacrificing start-up time or output transient response.

Control algorithms in the UCC28710 family allow operating efficiencies to meet or exceed applicable standards. The output drive interfaces to a MOSFET power switch. Discontinuous conduction mode (DCM) with valley switching reduces switching losses. Modulation of switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges.

The controllers have a maximum switching frequency of 100 kHz and always maintain control of the peak-primary current in the transformer. Protection features help keep primary and secondary component stresses in check. The UCC28710 allow the cable compensation to be programmed. The UCC28711, UCC28712 and UCC28713 devices allow remote temperature sensing using a negative temperature coefficient (NTC) resistor while providing fixed cable-compensation levels.

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Technical documentation

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Type Title Date
* Data sheet UCC2871x Constant-Voltage, Constant-Current Controller With Primary-Side Regulation datasheet (Rev. C) Jun. 30, 2017
Application note Flyback Aux Winding OVP and UVLO Fault Sensing Design and Troubleshooting Tips Aug. 31, 2021
Application note Minimize Standby Consumption for UCC287XX Family Aug. 01, 2019
Selection guide Power Management Guide 2018 (Rev. R) Jun. 25, 2018
Selection guide Current Sense Amplifiers (Rev. D) Apr. 04, 2018
Application note Troubleshooting TI PSR controllers Oct. 03, 2016
White paper Control Challenges for Low Power AC/DC Converters Oct. 02, 2015
White paper Control Challenges for Low Power AC/DC Converters (PPT) Oct. 02, 2015
More literature Exposing the Inner Behavior of a Quasi-Resonant Flyback Converter Oct. 29, 2013
User guide Using the UCC28711EVM-160 Sep. 14, 2012

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

UCC28711 evaluation module
document-generic User guide
The Texas Instruments UCC28711EVM-160 evaluation module (EVM) helps designers evaluate the performance of the UCC28711 Constant-Voltage, Constant-Current PWM with Primary-Side Regulation. The 5W EVM is used for evaluating an off line adapter for USB applications. It converts a 90V to 265V RMS input (...)
  • <10mW no load power
  • Primary Side Regulation (PSR) eliminates opto-coupler
  • +/- 5% Voltage & Current Regulation
  • 100 KHz max switching frequency enables high power density charger designs
  • Quasi-resonant valley switching operation for highest overall efficiency
  • Wide VDD range (35V) allows small bias (...)
document-generic User guide

The UCC28740EVM-525 evaluation module is a 10W off-line discontinuous mode (DCM) flyback converter that provides constant-voltage (CV) and constant-current (CC) output regulation. It uses optical coupler feedback for tight voltage regulation and improved the transient response to large load steps (...)

  • Universal AC input, 5V/2.1A output
  • <20mW no load power
  • Avg. efficiency > 80%
  • Opto-Coupled Feedback for Constant Voltage Regulation and Fast Dynamic Response
  • Primary Side Control for Tight Constant Current Performance (± 5% Output Current Regulation)
  • Internal 700V Start-Up Switch to Start up the Supply (...)

Design tools & simulation

SLUM464.ZIP (17619 KB) - PSpice Model
SLUM538.ZIP (119 KB) - TINA-TI Spice Model
SLUM539.TSC (224 KB) - TINA-TI Reference Design
SLUC590.ZIP (95 KB)

Reference designs

15-W multi-output off-line flyback reference design
PMP21927 — This reference design takes a universal Vac input and creates three isolated 15-Vdc outputs. The main output can be loaded up to 1-A and achieves over 86% efficiency. The other isolated 15-V outputs can be loaded to 50-mA. These outputs have linear regulators to keep the voltages within 1 (...)
document-generic Schematic
400-V to 690-V AC Input, 50-W Flyback Isolated Power Supply Reference Design for Motor Drives
TIDA-00173 This reference design provides isolated +24V (45W), ±16 V (4.5W), and +6V (0.5W) outputs to power the control electronics in variable speed drives.  The power supply can be either powered directly from 3-phase AC mains (380Vac to 690Vac) or can be powered from the DC-link voltage (400Vdc (...)
document-generic Schematic
Leakage Current Measurement Reference Design for Determining Insulation Resistance
TIDA-00440 This reference design measures insulation resistance up to 100 MΩ. It has an on-board isolated 500-Vdc power supply and an isolated signal conditioning circuit to measure the leakage current. This design is useful to find leakage due to insulation breakdown in transformer and motor windings.
document-generic Schematic
100/200Vac Input, 30W Isolated Power Supply Reference Design for Servo Drives
TIDA-00315 This reference design provides isolated 24Vdc, 16Vdc (x3) and 6V outputs to power the control electronics, IGBT module and fan for 100Vac/200Vac input servo drives. The power supply can be either powered directly from a single or 3- phase AC mains or can be powered from the DC link voltage. This (...)
document-generic Schematic
85-265VAC Input, 13.5V/0.9A PSR Flyback Reference Design
PMP11135 The PMP11135 reference design uses the UCC28711 to provide an isolated 13.5V at 0.9A output.  The UCC28711 implements primary-side regulation, eliminating the need for an opto-coupler and reducing the size and cost of the design.  This design meets Class B conducted emissions without the (...)
document-generic Schematic

CAD/CAE symbols

Package Pins Download
SOIC (D) 7 View options

Ordering & quality

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