ADC_SAR_Seq problem

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable

hi all cypress friends,

   

i run a voltage meter project

   

so i place a ADC_SAR_Seq , and a  analog input 

   

how could i set a right Vref,that could accept Voltage range from 0-5V , 

   

i saw the Vhref selection have a VDD , but it is 3.3V

   

 

   

Thanks for your help,

   

david

0 Likes
1 Solution
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Well, and? The resistor ladder will reduce the 5.0V input to (for instance) 3.0 V. then you do a re-calculation like Voltage = Measured * 5.0 / 3.0;

   

There is an API to set the gain and offset, so that the count to volt API does this automatically.

   

 

   

Bob

View solution in original post

0 Likes
4 Replies
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Welcome in the forum, David.

   

Because no voltage may be larger than Vdd you will need a resistor ladder to reduce your analog input to 3.3V.

   

 

   

Bob

0 Likes
Anonymous
Not applicable

but my input range need 0-5v input

0 Likes
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Well, and? The resistor ladder will reduce the 5.0V input to (for instance) 3.0 V. then you do a re-calculation like Voltage = Measured * 5.0 / 3.0;

   

There is an API to set the gain and offset, so that the count to volt API does this automatically.

   

 

   

Bob

0 Likes
Anonymous
Not applicable

thanks

0 Likes