TPL0501-100: Noise is getting generated from wiper

Annapoorneshwari K

Part Number: TPL0501-100

Tool/software:

Hi,

I'm getting frequency of 650Khz to 950Khz for the different wiper value from the wiper pin please find the below design.

My input frequency to the op-amp is 2Khz, but the noise frequency which is getting generated from the Digipot is effecting my overall output of the op-amp. When I do not give the input of 2Khz I'm getting the output of 650Khz to 950Khz from digipot, and when the digipot is removed there is no noise in the op-amp output. We were looking for different sclk frequency for operating the digipot, currently we are using 12.5 Mhz.

Please suggest the other clk frequency for operating the digipot, and please tell us how to solve this issue.

Thanks and Regards,

Annapoorneshwari M K

1 day ago

0 Katlynne Jones 1 day ago

TI__Mastermind 33168 points

Hi Annapoorneshwari,

To clarify, do you see this noise only while the digipot is being updated by SPI commands, or all the time?

Best,

Katlynne Jones

0 Annapoorneshwari K 1 day ago in reply to Katlynne Jones

Prodigy 10 points

Hi Katlynne Jones,

Yes, I'm getting the noise when my digipot value is updated by SPI commands, but not all the time.

Thanks and Regards,

Annapoorneshwari M K

0 Katlynne Jones 14 hours ago in reply to Annapoorneshwari K

TI__Mastermind 33168 points

Hi Annapoorneshwari,

Changing the SPI frequency likely won't help the issue then. in your PCB routing, are you using a ground plane and do you have your analog and digital traces kept separate?

If you remove the TPL0501-100 but continue sending SPI signals as if it was there, do you still see the noise?

Best,

Katlynne Jones

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TPL0501-100: Noise is getting generated from wiper