i am using optocoupler SFH1690 to shift a pwm of 5V at 20KHz to 12V 20KHz. but it seems that optocoupler wont work on this high frequency. so is there any other faster technique to do so. currently my pwm is no more a pwm at opto's output (because of rise or fall time issues) need help about is going wrong. i have trid it with SFH1690 and 4N24 but same behaviour. resistor with cathode is 470 ohms and i tried with diff values of pull up resistor and cathode resistor but was unable to get a pwm at o/p of optocoupler. instead a slop
closed as unclear what you're asking by Olin Lathrop, CL., uint128_t, Wesley Lee, Dmitry Grigoryev Apr 19 '17 at 14:03
Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.