Laptop power supply circuit using TOP269EG
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This laptop power supply circuit diagram is designed by Power Integrations, using TOP269EG integrated controller.
This laptop power supply circuit operates over a universal input range (90-265VAC) and provides a 19 V, 65 W output. It has been designed and tested to operate in a sealed enclosure in an external ambient temperature environment of up to +40 °C.
This laptop power supply circuit offers the following protection features:
- Output OVP with latching shutdown
- Latching open-loop protection
- Auto-recovery type overload protection
- Auto-restart during brownout or line sag conditions
- Accurate thermal overload protection with auto-recovery, using a large
This laptop power supply circuit diagram uses a TOP269EG off-line switcher IC, in a flyback configuration.
It regulates the output by adjusting the MOSFET duty cycle, based on the current fed into its CONTROL (C) pin.
TOP269 IC has an integrated accurate hysteretic thermal overload protection function which prevent thermal overload, when the junction temperature of U1 reaches +142 °C , the IC shuts down and automatically recovers once the junction temperature has decreased by 75 °C.
Open-loop faults cause the output voltage to exceed the specified maximum value. To prevent excessive output voltage levels in such cases, U1 utilizes an output overvoltage shutdown function.
The hardest part of making this power supply project is to design inductors L3,L4 and T1 transformer.
Bellow you can see technical specification about L3, L4 and T1 transformer.
If you want more details about this high efficiency power supply circuit you have all information needed in der243 application note founded on Power Integrations website.