Hi, I´m designing a power supply for a lamp with the FL7701 this is the controller IC. This lamp is for universal voltage from 127Vac to 277Vac. And the output is 30V to 700mA (after efficiency original power input is 25W). I´m using a STM10N60M2 mosfet as a switch, it has 600mOHMS RDS(on) and is capable to deal with 7.5A ID and 650VDS. I´m working with a 65KHz of switching frequency.
My problem is that the mosfet rises a lot of heat: 100-110°C whe input is 277VAC and 70-80°C when input is 127VAC. And my efficiency is low (80% aprox).
I changed Rgate to achieve fast turn on.
Does is normal low efficiency and high temperature on a mosfet at 65KHz?
How can I improve this?
My problem is that the mosfet rises a lot of heat: 100-110°C whe input is 277VAC and 70-80°C when input is 127VAC. And my efficiency is low (80% aprox).
I changed Rgate to achieve fast turn on.
Does is normal low efficiency and high temperature on a mosfet at 65KHz?
How can I improve this?
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