Impedance value of the pins

[Meghna]

Hi, 

1. In order to calculate the values of pull up & pull down resistor, in which section can we find the impedance information?

2. Should we use external crystal for OSC_IN & OSC_OUT pins?

3. If we are using USB2.0 FS feature what is the reference?

Thanks,

[TDK]

1) In the datasheet under "I/O port characteristics". It's about 40 kOhm.

https://www.st.com/resource/en/datasheet/stm32h743bi.pdf

2) It is up to you. A crystal is not required for USB device operation.

3) I don't understand the question. Are you looking for the reference manual?

https://www.st.com/resource/en/reference_manual/rm0433-stm32h742-stm32h743753-and-stm32h750-value-line-advanced-armbased-32bit-mcus-stmicroelectronics.pdf

It would have been better to mention the chip you're using rather than just the family. The H7 has a lot of different models.

[Andrew Neil]

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@Meghna wrote:

3. If we are using USB2.0 FS feature what is the reference?

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What do you mean by, "the reference"? For what chip?

Go to the 'Documentation' tab on the chip's Product Page, and search for "USB" ... ?