Adjustable Active Low Pass Filter for PSoC Vol.2

[TeMa_2997106]

Earlier, I asked the Adjustable Active LPF question here.

It was a configuration of SCF + Clock Generator, but it does not need to be PSoC because it controls only the clock when SCF is externally attached. (There is no merit to use PSoC) I would like to configure this only with PSoC devices (1-chip) by changing the Fc or lowering the resolution. Which parameter should I pay attention to?

If it can be configured with PSoC, it does not have to be PSoC4. (Both 5LP and 6 are OK)

Thanks,

Tetsuo

[AikoO_51 · Accepted solution]

Have you already tried DDS32, as suggested in previous thread you post?

You’ve already had SCF on your board, so you need to set just the clock to corner frequency.

You could set the cutoff frequency whatever you want, which is able to be controlled with <0.01Hz precision.

Unfortunately, there isn’t any document about DDS32.

Please just take a look at this thread, Need a programmable frequency generator.

[TeMa_2997106]

I have already checked this sample. This sample uses PSoC as a clock generator. My understanding is that this configuration has no merit in choosing PSoC.

Is a 1-chip solution (using PSoC internal switched capacitors) difficult to configure?

In the previous thread, such a sample is introduced. This looks like a one-chip solution. (No external SCF)

Thanks,

Tetsuo

[AikoO_51]

I’d like to just make sure about your request at once.

You have one PSoC device and externally SCF on your board, right?

But you don’t want to use a component of PSoC as just clock generator.

Do you want to know how to configure Low pass filter with not PSoC but the SCF, or Low pass filter on just the PSoC without external SCF?

Also do you just make sure which parameter to pay attention to in this thread, DelSig_ADC - Filter - VDAC streaming demo using DMA?

[TeMa_2997106]

Do you want to know how to configure Low pass filter with not PSoC but the SCF, or Low pass filter on just the PSoC without external SCF?

-- That is exactly things I want to know.

Also do you just make sure which parameter to pay attention to in this thread, DelSig_ADC - Filter - VDAC streaming demo using DMA?

-- Yes, I have already checked it. This reference has a fixed sampling rate and cutoff. How much resolution can be achieved when this is made variable?

Thanks,

Tetsuo

[AikoO_51]

Please try this sample code.

There is an additional memo about this project.

Just take a look at it.