STM32F103XC_09 Datasheet, PDF (89/123 Pages) STMicroelectronics – High-density performance line ARM-based 32-bit MCU with 256 to 512KB Flash, USB, CAN, 11 timers, 3 ADCs, 13 communication interfaces

STM32F103xC, STM32F103xD, STM32F103xE
Electrical characteristics
Figure 44. I²C bus AC waveforms and measurement circuit
VDD
VDD
I²C bus
4 .7 kΩ ^{4 .7 kΩ}
100Ω
100Ω
STM32F103xx
SDA
SCL
SD A
tf(SDA)
S TART
S TART REPEATED
tsu(STA)
S TART
tr(SDA)
tsu(SDA)
th(STA)
tw(SCKL)
th(SDA)
S TOP
tsu(STA:STO)
SCL
tw(SCKH)
tr(SCK)
tf(SCK)
tsu(STO)
ai14149b
1. Measurement points are done at CMOS levels: 0.3V_DD and 0.7V_DD.
Table 51.
SCL frequency (f_PCLK1= 36 MHz.,V_DD = 3.3 V)⁽¹⁾⁽²⁾
f_SCL (kHz)
I2C_CCR value
R_P = 4.7 k
400
0x801E
300
0x8028
200
0x803C
100
0x00B4
50
0x0168
20
0x0384
1. R_P = External pull-up resistance, f_SCL = I²C speed.
2. For speeds around 200 kHz, the tolerance on the achieved speed is of 5%. For other speed ranges, the
tolerance on the achieved speed 2%. These variations depend on the accuracy of the external
components used to design the application.
Doc ID 14611 Rev 7
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