Clock Source; Table 5. Low Voltage Limitation; Table 6. 32 Khz Crystal X1 Related Solder Bridges - ST STM32303C-EVAL User Manual

UM1567
Note: MCU I
DD
is open.
JP11 must be open (disconnect VDDA from all analog power VDD_ANA connected to the
analog circuit) for MCU I
Due to the characters of some peripheral components' specification, the low voltage
limitations related to the operating voltage of the peripherals (a component will not work
correctly when the power level is under the low voltage limitation) are shown in
Table 5.
Peripheral
Temperature sensor
Note: When an external DC 5V power supply is used to power the STM32303C-EVAL, it needs to
be connected to CN14 after verifying the correct polarity as explained in
Caution: RISK OF EXPLOSION IF THE BATTERY IS REPLACED BY AN INCORRECT TYPE.
DISPOSE OF USED BATTERIES ACCORDING TO THE INSTRUCTIONS.
2.3

Clock source

Two clock sources are available on the STM32303C-EVAL evaluation board for
STM32F303VCT6 and RTC embedded:
X1, 32 kHz crystal for embedded RTC
X2, 8 MHz crystal with socket for the STM32F303VCT6 microcontroller; it can be
removed from the socket when an internal RC clock is used.
Table 6.
Solder bridge
SB12
SB13
measurement can be done by the current meter which is mounted on JP12 when it
measurement.
DD
Low voltage limitation
Component
USB
CAN
32 kHz crystal X1 related solder bridges
PC14 is connected to the 32 KHz crystal when SB12 is open (default setting).
PC14 is connected to the extension connector CN6 when SB12 is closed. In such
a case, R196 must be removed to avoid disturbance due to the 32 KHz quartz.
PC15 is connected to the 32 KHz crystal when SB13 is open (default setting).
PC15 is connected to the extension connector CN6 when SB13 is closed. In such
a case, R197 must be removed to avoid disturbance due to the 32 KHz quartz.
Doc ID 023581 Rev 2
I/O name
CN12
CN3
U1
Description
Hardware layout and configuration
Low voltage limitation
USB
CAN
I2C2
Section
Table 5.
3V
3V
2.25V
3.13.
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