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

Product codes
NUCLEO-F103RB
Page of 54
Hardware layout and configuration
UM1724
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DocID025833 Rev 5
5.9 Solder 
bridges
          
Table 9. Solder bridges 
Bridge
State
(1)
Description
SB54, SB55 (X3 crystal)
(2)
 
OFF 
X3, C33, C34, R35 and R37 provide a clock as shown in 
 PF0/PD0/PH0, PF1/PD1/PH1 are disconnected from CN7.
ON 
PF0/PD0/PH0, PF1/PD1/PH1 are connected to CN12. (R35, R37 and SB50 
must not be fitted).
SB3,5,7,9 (DEFAULT) 
ON 
Reserved, do not modify. 
SB4,6,8,10 (RESERVED) 
OFF
Reserved, do not modify. 
SB48,49 
(X2 crystal)
(3)
 
OFF
X2, C31, C32, R34 and R36 deliver a 32 kHz clock. PC14, PC15 are not 
connected to CN7. 
ON
PC14, PC15 are only connected to CN7. Remove only R34, R36 
SB17
(B1-USER) 
ON 
B1 push button is connected to PC13. 
OFF 
B1 push button is not connected to PC13. 
SB12 (NRST)
ON
The NRST signal of the CN4 connector is connected to the NRST pin of the 
STM32 MCU.
OFF 
The NRST signal of the CN4 connector is not connected to the NRST pin of the 
STM MCU.
SB15 (SWO)
ON
The SWO signal of the CN4 connector is connected to PB3. 
OFF 
The SWO signal is not connected. 
SB11 (STM_RST)
OFF 
No incidence on STM32F103CBT6 (ST-LINK MCU) NRST signal. 
ON
STM32F103CBT6 (ST-LINK MCU) NRST signal is connected to GND. 
SB1 (USB-5V) 
OFF
USB power management is functional. 
ON
USB power management is disabled.
SB2 (3.3 V) 
ON
Output of voltage regulator LD39050PU33R is connected to 3.3V.
OFF 
Output of voltage regulator LD39050PU33R is not connected.
SB21 (LD2-LED) 
ON
Green user LED LD2 is connected to D13 of Arduino signal.
OFF
Green user LED LD2 is not connected.
SB56,SB51 (A4 and A5) 
ON
PC1 and PC0 (ADC in) are connected to A4 and A5 (pin 5 and pin 6) on 
Arduino connector CN8 and ST Morpho connector CN7. Thus SB46 and SB52 
should be OFF.
OFF
PC1 and PC0 (ADC in) are disconnected to A4 and A5 (pin 5 and pin 6) on 
Arduino connector CN8 and ST Morpho connector CN7.
SB46,SB52
(I2C on A4 and A5)
OFF
PB9 and PB8 (I2C) are disconnected to A4 and A5 (pin 5 and pin 6) on Arduino 
connector CN8 and ST Morpho connector CN7.
ON
PB9 and PB8 (I2C) are connected to A4 and A5 (pin 5 and pin 6) on Arduino 
connector CN8 and ST Morpho connector CN7 as I2C signals. Thus SB56 and 
SB51 should be OFF.
SB45 (VBAT/VLCD) 
ON
VBAT or VLCD on STM32 MCU is connected to VDD.
OFF
VBAT or VLCD on STM32 MCU is not connected to VDD.