Description

This user manual provides elementary information about an isolated

flyback with FSL518APG, it performs high efficiency and smaller

than 50 mW no−load power consumption. FSL518APG is an

integrated pulse width modulation (PWM) and 800 V power switch

with SENSEFET®, it can help to save external MOSFET and sense

resistor, increase power density and reliability. This application is

targeting auxiliary power supply for white goods and industrial

equipment, such as refrigerator, E−metering or similar types of

equipment.

The PWM controller includes an integrated variable frequency

oscillator, Under−Voltage Lockout (UVLO), Leading Edge Blanking

(LEB), optimized gate driver, internal soft−start, and temperature−

compensated precise current source for loop compensation and

self−protection circuitry. This design focuses mainly on the

FSL518APG current−mode PWM controller. Please refer to

FSL518APG’s materials to get more information about this device.

The FSL518APG is a current−mode PWM controller, it can have

better response to handle dynamic operation. Controller combines line

detection and burst−mode adjustment in one pin. It’s easy to achieve

these functionalities just need voltage divider and one Zener diode.

Line detection includes brown−in, brown−out and line OVP,

burst−mode adjustment is for fine tune audible noise and light load

efficiency. Of course, it also provides frequency reduction with

loading decreasing for gaining more design margin to improve light

load efficiency.

Key Features

• Integrated Rugged 800 V Super Junction

MOSFET with SENSEFET Technology

• Built−in HV Current Source for Start−up

• Peak−Current−Mode Control with Slope

Compensation

• Line Compensation for Maximum

Over−Power Limiting

• Advanced Soft−start for Low Electrical

Stress

• Peak−Current−Mode Control with Built−in

Slope Compensation

• Pulse−by−pulse Current Limit

• Line Brown−in, Brown−out,

and Over−Voltage Protection (LOVP)

• Adjustable Burst−mode Operation

• Frequency Hopping for Better EMI

• Various Protections:

♦ Auto Restart Mode: Brown−out, OLP,

OVP, AOCP and TSD

♦ Recovery Immediately by Triggering

Level: LOVP