Circuit Design of 40W Notebook Flyback Power Adapter

MOS power IC full range

1206 red anti-stick

Photocoupler

Summary:

working principle

Flyback power supply designed with Power Integrations' TOPSwitch-HX devices. The adapter power supply utilizes the high voltage MOSFET and multimode controller integrated in the TOP256EN (U1). The output voltage is regulated by shunt regulator U2 and optocoupler U3.

design feature

• Small number of components
• Meet Energy Star 2.0 energy efficiency requirements:
• No-load input power is very low: <210 mW at 230 VAC input
• Extremely efficient in standby and sleep modes
• Average efficiency >85%
• Excellent transient no-load response
• Automatic recovery of hysteresis overheat protection
• Configurable hysteresis or latch open loop protection
• Meet the requirements of limited power source (<100 VA)
• Elimination of secondary current detection circuit
• Power Integrations eSIP?
• Ultra-thin package
• Designed with low cost EE25 transformer

Circuit diagram of a 40W notebook power supply designed using TOP256EN

See the uploading documentation for details (click to download)