External crystal on STM32F303CCT6

[MSzła.1]

Hello all, I don't know why but my MCU STM32F303CCT6 don't work with external crystal, below schematics:

The used crystal is ABM3B-8.000MHZ-10-1-U-T with load capacitors 10pF. Later I find in STM Datasheet that I should use resistor on OSC32_OUT pin. Is the resistor necessary to work? Or maybe i use wrong crystal? Thanks a lot for help to solve my problem 🙂

[ONadr.1]

This should help

AN2867

Oscillator design guide for STM8AF/AL/S, STM32 MCUs and MPUs

[MSzła.1]

I saw this document but unfortunately after ordering the PCB. But it is puzzling to me that, for example, bluepill board designs have different solutions, one with a 1M resistor and the other without resistors. In the second case, this Bluepill board works, but unfortunately not in my case.

WeAct bluepill crystal schematics:

 

and noname bluepill board:

 

My PCB crystal schematics is exactly as in Weact bluepill?

Could I have damaged the crystal too high temp, hot air soldering?

[AScha.3 · Accepted solution]

no - you just connected to the wrong pins !

crystal for cpu clock is on PD0+1 , but you connected to 32kHz clk /crystal at PC14+15 !!!!

so connect it to right pins or use internal clk...

[waclawek.jan]

> bluepill board designs

They contain a STM32F103 (and these days, a random choice of some of the dozen clones), that's a different mcu with different oscillator design, and potentially uses a different crystal than you. So, you are comparing apples to a selection of various fruits and often also vegetables.

Read AN2867, mainly chapter 7, and also the parts which deal with the load capacitors calculation.

JW

[MSzła.1]

Thanks a lot! You have right

[waclawek.jan]

Nice catch! 🙂

JW