DRV8876EVM: Run TEC with LC Filter

Amir,

Yes, thank you!  It doesn't make sense to test without the load as the LC filter response will be underdamped.  This is a good app note on LC filter design.

https://www.ti.com/lit/an/slaa701a/slaa701a.pdf

If you increase the duty cycle, you should see current increase.  Is that the case?  

Regards,

Ryan

Hi Ryan,

I increased duty cycle all the way the current will increase but very little, I need be able to pull at least 1.5A so TEC cool or warm something.

The only way we were able to pull suffusion current was when we use electrolytic capacitor.

I have reviewed this document previously, but unfortunately whatever inductor and capacitor I choses cause fault due to current ripple. 

Thanks

Amir,

Switching from the same value electrolytic to the same value ceramic should result in the same cutoff frequency for your filter and the same frequency response.  Something is not right with the new caps you have recently purchased or connection to GND.

Can you double check that you have the same cap value now in filter that you had before?

Regards,

Ryan

Hi Amir,

Thank you for the information. We are very busy on our side so please give us another 24 hours to review the information and provide a reply. Thank you in advance for your patience.