AP3108LS

Document number: DS42105 Rev. 3 - 2

1 of 16

www.diodes.com

February 2021

© Diodes Incorporated

AP3108LS

HIGH-PERFORMANCE GREEN MODE PWM CONTROLLER

Description

The AP3108LS is a Current Mode PWM controller specially designed

for offline power supply that requires ultra-low standby power, high-

power density and comprehensive protection. The AP3108LS

coordinating with Diodes Incorporated

’s secondary side controller,

such as the AP4320, can be applied in the situation that requires for

constant CC and constant CV.

The maximum switching frequency of the AP3108LS is set at 65kHz.

The switching frequency can be modulated through green mode, in

which it will smoothly decrease along with the decreasing load. This

will cause the minimum switching frequency to be clamped at about

22kHz to avoid audible noise.

The AP3108LS provides an inner high-voltage start-up function

through HV pin which can save the use of the external start-up

resistor, reducing the standby loss. The HV pin also realizes X-CAP

discharge function. This is a useful function for power saving when

an X-CAP is connected to a system, for it will discharge the X-CAP

when the AC line voltage is off automatically without the need for

extra discharge resistors.

The AP3108LS integrates a VCC LDO circuitry, allowing the LDO to

regulate the wide range VCC_IN, which is rectified from auxiliary

winding to an acceptable value. This makes the AP3108LS a good

choice in wide range output voltage application.

There are also versatile system protections provided by AP3108LS,

such as secondary side OVP, secondary side UVP, constant output

current limit, cycle-by-cycle current limit, brown-out protection,

programmable external OTP, etc.

Features



Current Mode Control



High-Voltage Startup



Embedded VCC LDO to Guarantee Wide Range Output Voltage



Constant, Low Output Current in Output Short Situation



Low VCC Charge Current Reduces Standby Power in Output

Short Situation



Non-Audible-Noise Green-Mode Control



Internal Slope Compensation



Soft Start During Startup Process



Frequency Fold Back for High Average Efficiency



Constant Over Current Protection (COCP)



VCC Maintain Mode



X-CAP Discharge Function



Precise Secondary Side OVP and UVP



Programmable External OTP



Brown-Out Protection



Overload Protection



FOCP and SSCP Protection



Useful Pin Fault Protection



SSOP-9 (Type CJ) is Available



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)

SSOP-9 (Type CJ)

Applications



Switching AC-DC Adapter/Charger



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-

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

<1000ppm antimony compounds.