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The AP3304 is a Peak-Current control, Multi-Mode CCM+ QR PWM controller which is optimized for high performance, low standby power and cost effective offline flyback converters. At light load, the AP3304 operates in burst mode with 23kHz switching frequency to minimize standby power consumption and avoid the audible noise. When the load increases, the AP3304 will enter QR mode with frequency fold-back to improve system efficiency and EMI performance. In QR mode, the maximum switching frequency is clamp to 100kHz to reduce switching power loss. If the switching frequency reaches upper limit of the AP3304, the switching frequency starts to fall as the load increase until entering CCM with fixed switching frequency 80kHz to optimize power conversion efficiency. Furthermore, the frequency dithering function is built in to reduce EMI emission. Internal piecewise linear line compensation ensures constant output power limit over entire universal line voltage range. Comprehensive protection features are included, such as brown out protection, cycle-by-cycle current limit (OCP), VCC Over Voltage Protection (VOVP), Secondary-side Output OVP (SOVP) and UVP (SUVP), internal OTP, Over Load Protection (OLP) and pins’ fault protection.


  • Very Low Start-Up Current
  • Multi-Mode Control with CCM+QR
  • Soft Start During Startup Process
  • Frequency Fold Back for High Average Efficiency
  • Constant Over Current Protection
  • Secondary Winding Short Protection with FOCP
  • Frequency Dithering for Reducing EMI
  • Useful Pin Fault Protection:
    • SENSE Pin Floating
    • FB/Opto-Coupler Open/Short
  • Comprehensive System Protection Feature:
    • VCC Over Voltage Protection (VOVP)
    • Over Load Protection (OLP)
  • Brown Out Protection (BNO)
  • Secondary Side OVP (SOVP) and UVP (SUVP)
  • Mini Size Package of SOT26 (Type A1)
  • Totally Lead-Free & Fully RoHS Compliant
  • Halogen and Antimony Free. “Green” Device
  • For automotive applications requiring specific change control (i.e. parts qualified to AEC-Q100/101/200, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative. https://www.diodes.com/quality/product-definitions/


  • Switching AC-DC Adapter/Charger
  • ATX/BTX Auxiliary Power
  • Set -Top Box (STB) Power Supply
  • Open Frame Switching Power Supply

Product Specifications

Product Parameters

HV Start-UpCircuit No
StartupCurrent (µA) 1 µA
UVLOThresholdon/off (V) 15.8/6.5 V
Gate OutputCurrent (mA) +300/-800 mA
OscillationFrequency (kHz) 80(CCM mode) kHz
VOVP Auto-Recover
BNO Auto-Recover

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Orderable Part Number Buy from Distributor / Contact Sales Request Samples


Authorized Distributor Quantity Inventory Date Countries/Regions Buy Online
Digi-Key Electronics 2900 12/6/2021 Europe, Asia, North America Buy Now
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