ADC input resistance

per239955_st · ‎2006-01-02

Posted on January 02, 2006 at 10:58

per239955_st · ‎2006-01-02

Posted on January 02, 2006 at 10:11

Hi,

I would verify that I've understood the reference manual correctly.

At page 336 it says that the input resistamce of an ADC input (in round robin mode) is:

3000 [kOhm][MHz] /fmod

In my application PCLK2 is 32MHz and the prescaling factor set to 500.

According to my calculations the input resistance is 47kOhm.

Is this correct?

hichem2 · ‎2006-01-02

Posted on January 02, 2006 at 10:44

Hi Beach,

As you said the constant K is equal to 3000 [kOhm][MHz]

by the way the input resistance is 47MOhm not kOhm.

With best regards,

Hichem 😉

per239955_st · ‎2006-01-02

Posted on January 02, 2006 at 10:58

Aaahhh...

47MOhm was a 'better' value (my fault).

That makes it possible to use a lower prescaling factor without getting a redicoulisy low input resistance value. 😉

Thanx