AP3306

Document number: DS42803 Rev. 6 - 2

1 of 13

www.diodes.com

May 2022

© Diodes Incorporated

AP3306

HIGHLY INTEGRATED ACTIVE CLAMP FLYBACK PWM CONTROLLER

Description

The

DIODES™ AP3306 is a highly integrated Active Clamp Flyback

(ACF) controller optimally designed for offline power supplies to meet

ultra-low standby power, high power density, and comprehensive

protection requirements. The controller realizes non-complimentary

high-low-side control mechanisms to achieve Leakage Energy

Recycling and Zero Voltage Switching (ZVS) for supreme-efficiency

performance.

The AP3306 provides a high-voltage start-up function through the HV

pin, reducing standby loss. Moreover, the AP3306 integrates a VCCL

LDO circuit, allowing the LDO to regulate the wide range VCCL to an

acceptable value. This makes the AP3306 an ideal candidate for

wide-range output-voltage applications, such as USB-PD. The built-in

frequency dithering function greatly eases EMI design as well.

At no load or light load, the IC will enter burst mode to minimize

standby power consumption. The minimum switching frequency

(about 22kHz) is set to avoid audible noise. When the load increases,

the IC will enter ACF mode with frequency foldback to improve

system efficiency and EMI performance. The maximum switching

frequency (about 130kHz or 200kHz optional) is set to clamp the

switching frequency to reduce switching power loss.

Comprehensive protection features are included, such as Brown-Out

Protection (BNO), Cycle-by-Cycle Overcurrent Protection (OCP), VCC

Overvoltage Protection (VOVP), Secondary-Side Output OVP (SOVP)

and UVP (SUVP), internal Overtemperature Protection (OTP),

Overload Protection (OLP), and Pin Fault Protection.

Features



Active Clamp Flyback Topology with Recycled Leakage Energy

and Pseudo Zero Voltage Switching Functions



High-Voltage Startup



Embedded VCC LDO for VCCL Pin to Guarantee Wide Range

Output Voltage



Non-Audible-Noise Quasi-Resonant Control



Soft Start During Startup Process



Frequency Foldback for High Average Efficiency



Secondary Winding Short Protection with FOCP



Frequency Dithering for Reducing EMI



X-CAP Discharge Function



Useful Pin Fault Protection



CS Pin Floating Protection



FB/Opto-Coupler Open/Short Protection



Comprehensive System Protection Features:



VCC Overvoltage Protection (VOVP)



Overload Protection (OLP)



Brown-Out Protection (BNO)



Secondary-Side OVP (SOVP) and UVP (SUVP)



Packaged in the SO-10 (Type A1)



Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)



Halogen and

Antimony Free. “Green” Device (Note 3)



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/

Pin Assignments

(Top View)

1

2

3

4

10

9

8

7

VCCH

DEM

VCCL

HV

GND

CS

NC

FB

6

GDL

5

GDH

SO-10 (Type A1)

Applications



Smartphone quick chargers



Notebook computer adapters



High-Power density adapters/chargers: 30W/inch

3



Compact switching AC-DC adapter/charger



Suitable for variable output voltage applications (USB PD, QC,

SCP, VSCP, VOOC, AFC, etc.)



ATX/BTX auxiliary power applications



Set-top box (STB) power supplies



Open-frame switching power supplies

Notes:

1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant.

2. See https://www.diodes.com/quality/lead-

free/ for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and

Lead-free.

3. Halogen- and Antimony-

free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and

<1000ppm antimony compounds.