You are here

high impedance analog pin | Cypress Semiconductor

high impedance analog pin

Summary: 2 Replies, Latest post by danaaknight on 18 Oct 2013 09:29 PM PDT
Verified Answers: 0
Last post
Log in to post new comments.
Udayan Karmarkar's picture
2 posts

 Hi, Im giving variable analog input(max rating 5V) to PSoC 5lp in high impedance mode.Now my question is can I directly give the potentiometer input to PSoC?How much resistance does any analog pin provide in this mode? Will the current damage PSoC? 

Right now as precaution i have connected 1k in series with POT,Psoc is taking floating value when i switch the input near to zero volts.The reason being psoc is unable to detect ground because of that 1k ohm.


user_119377051's picture
866 posts

Hi upk

Of course in Analog high Z mode,

The input resistance should be exceed a few mega ohm, I guess.

Instability around Vss is cause from rail-to-rail characteristic

For example, acording to the ADC datasheet

Analog input has characteristic such as shown in this picture,

It's depending upon the setting.

user_14586677's picture
7646 posts

If the pot ranges outside Vdda, there is a spec on allowed injection

current into a pin to prevent latchup. Also a max current of 100 uA

thru input protection diode.


Regards, Dana.

Log in to post new comments.