Why I am not getting same voltage with two Dithering VDAC?

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

cross mob
lock attach
Attachments are accessible only for community members.
Anonymous
Not applicable

Hello Every Body,

   

I am using two dithering VDAC having same clocks. Now the problem is, one dithering VDAC is generating correct voltage but the other is not.

   

Please see pic attached.

   

Looking forward for your reply.

   

Regards

   

Awais

0 Likes
1 Solution
Anonymous
Not applicable

If the board is CY8CKIT-050 PSoC 5LP Development Kit then P2_0 is connected to the LCD module

View solution in original post

0 Likes
8 Replies
RoBO_1287886
Level 4
Level 4
First solution authored 25 replies posted 10 replies posted

Helle maknight,

   

Into your design, one VDAC works correctly.

   

Could you check the pin configuration of the output?

   

[NOTE] May be you need to disconnect all external components.

   

An other things, please check into your code that all your VDACs are started.

   

 

   

yours,

   

Rob1

0 Likes
Anonymous
Not applicable

Dear Rob1,

   

Thank you for your reply.

   

I already disconnect all external components and checked the outputs but the problem is still there. Also, the components are started correctly.

0 Likes
RoBO_1287886
Level 4
Level 4
First solution authored 25 replies posted 10 replies posted

Hi maknight,

   

About the VCCIO of the bank used by your VDAC outputs: Does it the same "bank" for the 2 VDACs?

   

 

   

Could change the output pin (of your FAIL VDAC) to try on different bank?

   

Could your try the same bank used with your first VDAC?  This one works!

   

 

   

yours,

   

Rob1

0 Likes
Anonymous
Not applicable

"About the VCCIO of the bank used by your VDAC outputs"

   

What does this means? from where i can verify it?

   

regards

   

Awais

0 Likes
Anonymous
Not applicable

What development card do you use and what pins are used for the VDAC outputs ?

   

Do you measure the output with open pins or with the circuits indicated in you posted diagram?

   

Is the output static or varying when you measure it?

   

Can the Opamp_Ex_Neg_CHA influence the measured outputs?

0 Likes
Anonymous
Not applicable

Hi,

   

I am using PSOC 5LP (LP035), and I using pins P1_5 and P2_0. I measured it with both of them. Both have certain offset too.

   

The output was varying(with circuit) before but now I placed a voltage follower. That problem is gone now. Now it is static.

   

No, I don't think so that the Opamp_Ex_Neg_CHA can influence.

   

Looking forward for your suggestion.

0 Likes
Anonymous
Not applicable

If the board is CY8CKIT-050 PSoC 5LP Development Kit then P2_0 is connected to the LCD module

0 Likes
Anonymous
Not applicable

Oh Yes it is connected to that pin.

   

It is better now but the offset is still there.

0 Likes