How to design USB for STM32F105VCT6

[WPong.1]

Hi All,

I want to design USB schematic for STM32F105VCT6. I read Introduction to USB hardware and PCB guidelines using STM32 MCUs(AN4879) and it said that STM32F105/STM32F107 has Pull-up resistor on USB_DP line.

Question 1

Can I design USB schematic with no Pull-up resistor on USB_DP? And no need any config about embedded Pull-up resistor in software?

Question 2

Should I put some resistor between USB connector and STM32F105 on both USB D+,D- ? If yes, what value should add.

This is example schematic from stm32 bluepill. I saw there are resistor between USB connector and STM32F103

 

Thank you for your answer

[AScha.3]

Hi,

see ds:

-> no need for any external resistor .

(and dont ever use pullup to +5V ! Thats just wrong. USB has 3v3 signal levels...! )

+ only (old) F103 needs 1k5 pullup to 3v3 .

[WPong.1]

What is HNP/SNP/IP ?

[STOne-32]

Dear @WPong.1 ,

 

Here you go :

https://www.st.com/resource/en/datasheet/stm32f107vc.pdf#page95

No need for Serial resistance neither the pull-up . You need to connect D-, D+ and VBus to the connector , in case of your device is bus powered that means all power from VBus : 5volts from Host , in case of Host follow the recommendation as well.

Hope it helps ,

STOne-32