High precision external clock

[poorchava]

My application is using ESP32-WROOM-32E-N16 module. In the new revision we need to implement a very high stability clock based on a VCTCXO oscillator. Clock signal fed into ESP32 can be either 3.3V LVCMOS or 0.6Vpp clipped sinewave.

Is there a way to feed external system clock into this module? If not, is there another ESP32 module that has this capability? Or do we need to design our own module for this?

[MicroController]

What do you mean by 'feed into' the ESP? Do you want to measure the signal or do you want to drive parts of the ESP from it?
Frequency?

[poorchava]

I want to clock ESP32 from it, instead of build-in 40Mhz crystal that is in the module. I need the PWM frequency to be ultra-high stability. I can't disclose what this is for.

Frequency of the high stability clock is whatever i want it to be. Other devices use 20MHz, but it can be 40Mhz or something else as well.

[MicroController]

Should be possible:

Connect the external clock input to the XTAL_P pin.

viewtopic.php?t=2742#p13328

(Not directly with a module though, unless you remove the existing crystal first.)

[poorchava]

Unfortunately this is for medium volume production, so modifying modules is out of question. This means we would have to roll our own module, right?

[MicroController]

I need the PWM frequency to be ultra-high stability.

The MCPWM can be synchronized by an external signal.
You may also be able to implement a kind of PLL in software, taking the high-precision clock signal as reference and continuously adjusting the PWM frequency to match.
Whether or not that's a viable option depends on your specific requirements of course.