Kinetis Microcontrollers中的主题 Can I Disable Decimation Filter in KM34

Can I Disable Decimation Filter in KM34

martinzhang — Mon, 24 Aug 2020 01:57:00 GMT

Hi,

I’m using AFE of KM34, I noted that the decimation filters will affect the ADC frequency response, my quest is: Can I disable the decimation filter to improve the ADC frequency response?
I tried to disable the decimation filters but the AFE cannot work correctly?

Best Regards,

Martin

Re: Can I Disable Decimation Filter in KM34

Omar_Anguiano — Tue, 25 Aug 2020 19:06:44 GMT

Hello Martin Zhang

You can disable the Decimation filter with the field AFE_CHx_CFR(DEC_EN).

Let me know if this is helpful, if you have more questions do not hesitate to ask me.

Best regards,

Omar

Re: Can I Disable Decimation Filter in KM34

martinzhang — Wed, 26 Aug 2020 00:39:38 GMT

Hello Omar,

Thank for your reply!

I have tried to disable the Decimation filter again, set the flag DEC_EN to 0 in AFE_CHx_CFR, but the MCU never enter the AFE interrupt. I change back DEC_EN to 1 and the AFE work correctly.

Is there any other related setting to disable decimation filter and keep AFE works correctly?

Best Regards,
Martin

Re: Can I Disable Decimation Filter in KM34

Omar_Anguiano — Thu, 27 Aug 2020 19:04:58 GMT

Hello Martin Zhang

I consulted this with an internal team. Unfortunately, the Decimation filter must be enabled. If it is not enabled the AFE won't work correctly.

I apologize for the inconvenience this may cause you. If you have more questions do not hesitate to ask me.

Best regards,

Omar