STMicroelectronics Nucleo Development Board for STM32 Microcontrollers NUCLEO-F103RB NUCLEO-F103RB Data Sheet

DocID025833 Rev 3

48

There are three ways to manage the external high-speed clock (HSE):


MCO from ST-LINK: from MCO of the ST-LINK MCU (U2 on schematic). This 
frequency cannot be changed, it is fixed at 8

 

MHz and connected to PF0/PD0/PH0-

OSC_IN of STM32 microcontroller. 
The following configuration is needed:
–

SB54, SB55 OFF

–

R35,R37

 

removed

–

SB16, SB50

 

ON



HSE oscillator on-board from X3 crystal (not provided): for typical frequencies and 
its capacitors and resistors, please refer to STM32 microcontroller datasheet. The X3 
crystal has the following characteristics: 8

 

MHz, 16PF, 20PPM, and DIP footprint.

The following configuration is needed:
–

SB54, SB55 OFF

–

R35, R37 soldered

–

C33, C34 soldered with 20pF capacitors

–

SB16, SB50

 

OFF



Oscillator from external PF0/PD0/PH0: from an external oscillator through pin 29 of 
the CN7 connector. 
The following configuration is needed:
–

SB55 ON

–

SB50

 

OFF

–

R35,R37 removed

If PF0/PD0/PH0 and PF1/PD1/PH1 are used as GPIOs instead being used as a clock:
–

SB54 and SB55 are ON, 

–

R35 and R37 are removed, and

–

SB50 (MCO) is OFF (default configuration).

Part number example:

9SL8000016AFXHF0

Manufacturer:

Hong Kong X'tals Limited

Website:

http://www.hongkongcrystal.com/en/index.php