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

PSoC™ 5, 3 & 1 Forum Discussions

Len_CONSULTRON
Level 9
1000 replies posted 750 replies posted 500 likes received
Level 9

Hi,

Happy Holidays!

I just posted a new pre-component with Demo project to the "Code Examples" forum.

It is a 14-bit Voltage DAC using dithering technique to gain additional resolution beyond the inherent 8-bits of the Cypress VDAC8.

If I've piqued your interest, here is a link to the project thread and more information.

DVDAC14-14-bit-VDAC-using-the-Dithering-Technique 

Enjoy!

Len
"Engineering is an Art. The Art of Compromise."
1 Solution
Len_CONSULTRON
Level 9
1000 replies posted 750 replies posted 500 likes received
Level 9

The DVDAC14 post has been updated with a PSoC3 version of the pre-component.

Len
"Engineering is an Art. The Art of Compromise."

View solution in original post

0 Likes
4 Replies
odissey1
Level 9
First comment on KBA 1000 replies posted 750 replies posted
Level 9

Len,

Thank gou for posting a preview of the component.

Did you measure INL / DNL curves at 14 bits? 

/odissey1

0 Likes
Len_CONSULTRON
Level 9
1000 replies posted 750 replies posted 500 likes received
Level 9

/odissey1,

No I didn't measure the INL and DNL.  I'm using the INL and DNL of the VDAC8.

I don't have equipment sensitive enough to measure every bit count.  Maybe you're better situated.

In order to visualize some semblance of linearity, I use a PGA @ 50 gain to see the steps large enough on my scope.

Here's a scope pic of a 65 step ramp from 0.01V to 0.026V on the 4V range with the ramp going through the PGA@50.

Len_CONSULTRON_0-1640143772132.png

The scope plot is on Display (Average of 1 sample) with a BW limit of 20 MHz.

Since the dithering is effectively a PWM of two consecutive VDAC8 counts, the DNL and INL should only be as good as the dithering bit pattern used at any of the dither DAC code values.  

I tried to be careful to space the '1's and '0's as evenly as possible.

 

Len
"Engineering is an Art. The Art of Compromise."
0 Likes
Vasanth
Moderator
Moderator 250 sign-ins 500 solutions authored First question asked
Moderator

Hi Len,

Thanks for sharing the solution with community 🙂

Best Regards,
Vasanth

0 Likes
Len_CONSULTRON
Level 9
1000 replies posted 750 replies posted 500 likes received
Level 9

The DVDAC14 post has been updated with a PSoC3 version of the pre-component.

Len
"Engineering is an Art. The Art of Compromise."
0 Likes