Using a PWM controller external MOSFET interfacing from chip

[j_writer]

I would like to use a PWM chip in a 100V + buck converter application but the ICs are rated at 30-40 volts max. Would like to drive an external MOSFET and I need help interfacing from the chip output to the FET. The typical ICs are... TL2842, TPS40200, or UC1573. This may take a little discussion back and forth but can anybody help?

 

[sec]

Re: Using a PWM controller

the TL2842 is good, use and calculate the input resistor (connected to VCC) ...
the IC has an internal regulator, a Zener diode. Look at the datasheet to calculate the power dissipated in the chip and you are good to go !

Why don`t you want an isolated output (using a transformator). By experience, start at 30V then go to 40V, etc to test your circuit.

 

[j_writer]

Re: Using a PWM controller

This figure shows what I would like to do. For now it is a concept, until I am sure it's OK to use a 35 Volt part in a 140 Volt application! Are these controllers commonly used this way?

 

[--jason--]

Using a PWM controller

using a transformer or a gate driver are better solutions ,since it provide isolation, and reduce the stress for some components.

 

[j_writer]

Re: Using a PWM controller

Thanks for the gate driver suggestion. Please see new thread...