IMX7 ADC question

[frankyhsu]

Hi

I am checking the ADC input resistance for IMX7 and I found the R_IEXT need to be small to driver the ADC input. Does it mean we need to have 50~250 ohm pull-high to 1.8V and use 10k NTC to GND? Like the below schematic?

Franky

[CarlosCasillas · Accepted solution]

Hi Franky,

Such parameter is not specifically about such hardware configuration (although the idea is maintaining the impedance as low as possible). However, you could refer to the following documents/application notes about ADC parameters and recommendations:

http://www.nxp.com/assets/documents/data/en/application-notes/AN2438.pdf

http://www.nxp.com/assets/documents/data/en/application-notes/AN1058.pdf

http://www.nxp.com/assets/documents/data/en/application-notes/AN4373.pdf

 http://www.nxp.com/assets/documents/data/en/supporting-information/Analog-to-digital-Converter-Train...

Hope this will be useful for you.
Best regards!
/Carlos
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------