How to Replace an Opto-MOS (PhotoMOS Relay) Using Combination of Other Components?

[Saeedk9574]

Hi everyone,

I am working on a circuit that needs an opto-mosfet like 210EH or CPC1008N which I attached the datsheets.
Because I can not find the mentioned part numbers in the market of my country, I’d like to replace the opto-MOS with a combination of discrete components to achieve the same functionality.
I’m considering using a MOSFET and an optocoupler (with transistor), but I’m not entirely sure about the best way to design it. Here are my specific questions:

1. What components (e.g., MOSFET, transistor, resistors, diodes) would you recommend for this application?
2. How should I design the driver circuit to ensure reliable switching?

If anyone has experience with this or can suggest a circuit design, I’d greatly appreciate your input!

Thanks in advance for your help!

 

[FvM]

What's your specification, e.g. for Ciso? Using a regular optocoupler involves an auxiliary power supply for the gate driver, e.g. DC/DC converter. It will increase Ciso by at least factor of 10.

Things can be much simpler if you don't need perfect isolation between in- and output.

 

[danadakk]

Characteristics of load you are switching ? Current and V, Inductive, Resistive.... Speed desired.

 

[dick_freebird]

Look for isolating MOSFET drivers, an opto is real weak. But opto MOS might be unidirectional or AC bidirectional and that bears a lot on interface "guts".