AP3303

Document number:DS41016 Rev. 5 - 2

1 of 16

www.diodes.com

May 2019

© Diodes Incorporated

AP3303

QUASI-RESONANT PWM CONTROLLER

Description

The AP3303 is a peak-current control, Quasi-Resonant (QR) PWM

controller which is specially designed for offline power supply that

requires

ultra-low

standby

power,

high-power

density

and

comprehensive protection. It can coordinate with secondary side

USBPD or quick charger controller which can provide a flyback

charger solution.

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

standby power consumption. The minimum switching frequency

(typical: 24kHz) is set to avoid the audible noise. When the load

increases, the IC will enter QR mode with frequency foldback to

improve system efficiency and EMI performance. The maximum

switching frequency (typical: 120kHz) is set to clamp the QR

frequency to reduce switching power loss. Furthermore, the frequency

dithering function is built in to reduce EMI emission.

The AP3303 provides an inner high-voltage start-up function through

HV pin which can reduce the standby loss. Moreover, The AP3303

integrates a VCC LDO circuitry, allowing the LDO to regulate the wide

range VCC_IN to an acceptable value. This makes the AP3303 to be a

good choice in wide range output voltage application.

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, VCC Over Voltage Protection

(VOVP), Secondary-side Output OVP (SOVP) and UVP (SUVP),

internal OTP, Over Load Protection (OLP) and pins’ fault protection.

Combined with Diodes Incorporated’s synchronous controller

APR347, the AP3303 system can achieve the higher power

conversion efficiency and the better thermal performance.

Features



Quasi-Resonant Operation under all Line and Load Condition



Non-Audible-Noise Quasi-Resonant Control



High-Voltage Startup



Embedded VCC LDO to Guarantee Wide Range VCC_IN Voltage



Low VCC Charge Current Reduces Standby Power in Output

Short Situation



Adaptive Burst Mode Operation with Output Voltage



Adaptive Output Power Limit with Output Voltage



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



VCC Maintain Mode



Useful Pin Fault Protection:

SENSE Pin Floating

FB/Opto-Coupler Open/Short



Comprehensive System Protection Feature:

Programmable External OTP

Over Load Protection (OLP)

Brown In/Out Protection

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



SSOP-9 (Type CJ) is Available



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



Halogen and Antimony Free. “Green” Device (Note 3)

Pin Assignments

(Top View)

SSOP-9 (Type CJ)

Applications



Switching AC-DC Adapter/Charger



ATX/BTX Auxiliary Power



Set-Top Box (STB) Power Supply



Open Frame Switching Power Supply

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-fre

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

<1000ppm antimony compounds.