UART isolation using Optocoupler

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vamanan

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Hi,
I am using 8051 for serial communication. It talks with another microcontroller at TTL level. So I think there is no need for MAX232. Am I correct ?. Is it enough if I connect tx of miconA to rx of moconB and rx miconA to tx of miconB. Is it like this or I need to connect some other way?. If I want to isolate this path, how can I do that?.
Regards,
Vamanan Kutty
 

Hi

You can use low speed low cost couplers. You should just ensure the LED drive current and secondary side pull up resistor are OK for values given in datasheet.

I saw there is a new coupler which with very low drive current can work: ACPL-054L. You can directly drive it from many microcontrollers, as LED current can be so low as 3mA.
 

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