cancel
Showing results for 
Search instead for 
Did you mean: 

PSoC™ 5, 3 & 1

Anonymous
Not applicable

Hi everyone,

   

I try to read a 0 to 2.5V with the ADCINC14, i use the REFMUX for read 8 port, and I use the external ref (P2[4], P2[6]).

   

Analog Power : SC On/Ref High

   

Ref Mux : P2[4]+/-P2[6]

   

VDD : 5V

   

P2[4] : 0V

   

P2[6] : to a ref 2.5V

   

 

   

Problem; can't read more than ~15818 counts...

   

2^14 = 16384

   

ref 2.5V/16384 = 152.588uV

   

15818 * 152.588uV = 2.414V <- this is my problem, if the input is 2.5V or greater never read more than this.

   

 

   

Thanks for reading and helping me 🙂

0 Likes
1 Solution
pushekm_21
Employee

 Corso,

   

 

   

I need to check this out but one thing which need to correct over here is the proper selection of ref voltage. With the current selection, negative voltage of the device is -2.5V because of P2[4] +/- P2[6]. You can connect a 1.25V signal on both the pins, this'll make the REFHI setting as 2.5V and REFLO as 0V.

   

 

   

I'll check this at my end and shall let you know.

   

 

   

Best regards,

   

Pushek

View solution in original post

0 Likes
2 Replies
pushekm_21
Employee

 Corso,

   

 

   

I need to check this out but one thing which need to correct over here is the proper selection of ref voltage. With the current selection, negative voltage of the device is -2.5V because of P2[4] +/- P2[6]. You can connect a 1.25V signal on both the pins, this'll make the REFHI setting as 2.5V and REFLO as 0V.

   

 

   

I'll check this at my end and shall let you know.

   

 

   

Best regards,

   

Pushek

View solution in original post

0 Likes
Anonymous
Not applicable

Pushek,

   

Thank you for the info, this has solved my problem by using a 1.25Vref on p2[4] and p2[6].

   

First time I see this way of using an external reference.

   

Thanks,

   

Corso

0 Likes