Primary Feedback CC/CV PWM Controller for Flyback Converters


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The R7711A is a current mode PWM controller which includes primary side voltage feedback technology. It controls the output voltage and current accurately without shunt regulator and opto-coupler on secondary side to reduce the part count and save costs.

The R7711A is designed especially for low power applications, such as chargers for cell phones, PDAs, and other mobile products. Complete protections are provided, such as output Under- Voltage Protection, output Over-Voltage Protection, VDD Over-Voltage Protection, Over-Temperature Protection, and Secondary Rectifier Short-circuit Protection. The ultra low start-up current and operating current of the R7711A achieves low power consumption in standby mode. The R7711A supports burst switching green mode operation to meet CEC regulations and Energy-Star requirements.


  • Switching AC/DC Adaptor and Battery Charger
  • DVD Open Frame Power Supply
  • STB Power
  • Cell Phone Charger
  • Networking Power Supply
  • AC-DC Power Supply
Key Spec.
Status Obsolete
Feedback Regulation Mode PSR
Switching Frequency_Normal (kHz) 65
Peak load Application No
HV Start-up No
CCM/Valley Multi-mode CCM/Hard Switching Multi-mode
Programmable Burst/Green-mode No
Brown-in/out Yes (Buck cap.Side)
External OTP No
UVLO ON (V) 14.5
UVLO OFF (V) 8.5
VDD OVP (V) 27
Features Current Mode Control;Cycle-by-Cycle Current Limit;OCP;OVP;SCP;UVP
Package Type SOT-26
  • Programmable Primary-Side CC/CV Regulation
  • Low No Load Input Power (<30mW at 230VAC)
  • Burst Switching Green Mode PWM Operation
  • Low Start-up Current (<10mA)
  • Easy EMI Solution
    ► Built-in Jittering Frequency
    ► Built-in Soft Gate Driver
  • Programmable Cable Drop Compensation
  • Adjustable Propagation Delay Compensation
  • VDD Over-Voltage Protection (VDDOVP)
  • Output Over-Voltage Protection (OVP)
  • Output Under-Voltage Protection (UVP)
  • Secondary Rectifier Short-Circuit Protection (SRSP)
  • Internal Over-Temperature Protection (OTP)
  • RoHS Compliant and Halogen Free
TitleLast UpdateShareDownload
Primary Feedback CC/CV PWM Controller for Flyback Converters2011/09/21