EVAL-ADAU1452REVBZ-UG-1662
I need an all pass filter of 1st degree with dynamically tunable characteristic frequency (i.e. 90 degree frequency).
The phase shift used would be 0 to -20 degree and the frequency bandwidth of the tune-input needs to be between 0 Hz and 100Hz.
Is there a filter block offering these features?
Alternatively I could use a dynamically tunable delay between 0 and 20µs (i.e. the steps need to change smoothly and they need to be significantly smaller than the sample period.
Is it possible to realize this?
Hello RLutz215,
I am not certain I understand what you need to do but I will mention a few things that might help. Others on the forum might chime in.
We do have a tracking filter. It can be set for no boost but I am not sure if the phase will change when the center frequency will be changed. Also, it is a 2nd order filter:
https://wiki.analog.com/resources/tools-software/sigmastudio/toolbox/Filters/TrackingFilter
Depending on how many different settings you need you could use the first order lookup filter. It will store coefficients for multiple curves that are selected from a control port. If you have a controller in your system then you can go in and change the coefficients so they do what you want.
Regarding the tunable delay.
In the toolbox there is a fractional delay that will interpolate delay values that are not divisible by the sample period.
https://wiki.analog.com/resources/tools-software/sigmastudio/toolbox/basicdsp/fractionaldelay
Dave T
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