Sorry for long time no try, I had another important work to do. I tried LEDC 12MHz clock generating approach an it works, somehow it can set the clock, BUT if I measure it on oscilloscope I get clock signal ranging from 11.4 to 13.3 MHz. This is unusable ...

Thanks, which pin function is then used to output the 12 MHz clock signal to GPIO (TRM chapter 4.9 table ) ? For the first (ADC clk) solution. I am not very familiar with I2S..

About LEDC/PWM, I am not sure but I think frequency cannot be easily changed (base 80MHz) ? And 80 MHz is not very good ...

Hi,

is it possible to generate 12 MHz clock signal on some ESP32-WROOM32 pin (to be used as square clock for external component) ?

The duty resolution can be lowered down to 1 bit in which case the maximum frequency is 40 MHz, but only the duty of 50% is available

Which looks good, means that ...