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Q&A Do we need to use pull up resistors in SPI lines when the ADC and Microcontroller are far apart

I have an ADC board. This board will communicate with a STM32 develoment board via SPI interface. I am using jumper cables for connecting the ADC SPI lines to ST32 evaluation board. Below is my AD...

1 answer · posted 8mo ago by newbie‭ · last activity 8mo ago by Olin Lathrop‭

Question ADC

#2: Post edited by

newbie‭ · 2026-01-08T16:00:43Z (8 months ago)

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I have an [ADC](https://www.analog.com/media/en/technical-documentation/data-sheets/ad5940-5941.pdf) board. This board will communicate with a STM32 develoment board via SPI interface. I am using jumper cables for connecting the ADC SPI lines to ST32 evaluation board.
Below is my ADC schematic. I gave the ADC schematic for review to the concerned analog devices team. The response received is given below.
> We recommend adding the pull-up resistors on all lines. Generally, a 10k pull-up resistor can be used. However, if track/distance is long i.e. more than 5 to 8 inches then we would suggest using a 4.7k resistor. It could be useful to design these pull-up resistors in and they can be used as a ‘population option’.
![Image_alt_text](https://electrical.codidact.com/uploads/93qjsgasj0e19vgd9ekc2wm76dzz)
May I know your thoughts.

I have an [ADC](https://www.analog.com/media/en/technical-documentation/data-sheets/ad5940-5941.pdf) board. This board will communicate with a STM32 develoment board via SPI interface. I am using jumper cables for connecting the ADC SPI lines to ST32 evaluation board.
Below is my ADC schematic. I gave the ADC schematic for review to the concerned analog devices team. The response received is given below.
> We recommend adding the pull-up resistors on all lines. Generally, a 10k pull-up resistor can be used. However, if track/distance is long i.e. more than 5 to 8 inches then we would suggest using a 4.7k resistor. It could be useful to design these pull-up resistors in and they can be used as a ‘population option’.
![Image_alt_text](https://electrical.codidact.com/uploads/93qjsgasj0e19vgd9ekc2wm76dzz)
For robustness and reliability (over time) Analog devices suggested to include pull-up resistors on the connector J4 going to the SPI pins.
May I know your thoughts.

#1: Initial revision by

newbie‭ · 2026-01-08T14:48:09Z (8 months ago)

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Do we need to use pull up resistors in SPI lines when the ADC and Microcontroller are far apart

I have an [ADC](https://www.analog.com/media/en/technical-documentation/data-sheets/ad5940-5941.pdf) board. This board will communicate with a STM32 develoment board via SPI interface. I am using jumper cables for connecting the ADC SPI lines to ST32 evaluation board.

Below is my ADC schematic. I gave the ADC schematic for review to the concerned analog devices team. The response received is given below.


 > We recommend adding the pull-up resistors on all lines. Generally, a 10k pull-up resistor can be used. However, if track/distance is long i.e. more than 5 to 8 inches then we would suggest using a 4.7k resistor. It could be useful to design these pull-up resistors in and they can be used as a ‘population option’.

![Image_alt_text](https://electrical.codidact.com/uploads/93qjsgasj0e19vgd9ekc2wm76dzz)

May I know your thoughts.

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