How to fix MCO clock on NUCLEO-H743ZI2 (with MB1364C board)

[DL.683]

How to fix MCO clock on NUCLEO-H743ZI2 (with MB1364C board)

Hi,

I am trying to evaluate H743ZI2, I got NUCLEO-H743ZI2.

I am trying to use HSE from MCO, but MCO clock is extremely unstable, jitter as much as 0.2%.

I verified this on 2 such boards, right from the box.

I also checked other Nucleo boards: MB1312 with L4R5ZI and MB1137 with F767ZI and they have pretty stable clock.

On MB1364C board I checked clock on:

R21 resistor - clock input to ST-Link chip - good

R5 resistor - MCO clock output from ST-Link chip - bad

SB45 - MCO - bad

So, it appears that ST-Link chip is misconfigured and generates bad clock from good.

Question: is it possible to fix it?

Thank you

[john rubis]

I am using the same board and have seen a similar problem. How did you solve this? Thinking I might need to populate X3 and disconnect the MCO to the MCU.