Table 48. Scl Frequency; Figure 20. I 2 C Bus Ac Waveforms And Measurement Circuit - STMicroelectronics STM32L151RE Manual

STM32L151xE STM32L152xE
1. R = series protection resistor.
S
2. R = external pull-up resistor.
P
3. V
DD_I2C
4. Measurement points are done at CMOS levels: 0.3V
1. R = External pull-up resistance, f
P
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 is ±2%. These variations depend on the accuracy of the external
components used to design the application.
2
Figure 20. I C bus AC waveforms and measurement circuit
is the I2C bus power supply.
Table 48. SCL frequency (f
f (kHz)
SCL
400
300
200
100
50
20
SCL
DocID025433 Rev 8
and 0.7V
DD DD.
= 32 MHz, V
PCLK1
2
= I C speed.
Electrical characteristics
(1)(2)
= V = 3.3 V)
DD DD_I2C
I2C_CCR value
R = 4.7 kΩ
P
0x801B
0x8024
0x8035
0x00A0
0x0140
0x0320
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