Minimum Open Loop Delay
Posted: Mon Dec 09, 2013 8:18 am
I've searched the specs and forum for this information without finding it so I'm asking here.
I want to experiment with a sort of Karplus system were the delay is supplied by a Spin chip but with other non-digital processing in the feedback loop but external to the Spin chip. Therefore the loop cycle time will include the conversion time of the ADC and DAC plus the variable digital delay of some algorithm in the chip plus any delay in the external analog circuit.
What I want to know is the time that the ADC and DAC conversion times will add to the loop as this will set the minimum loop time. Ideally I'd like to be able to vary the total delay in a range of about 1 to 2 ms and preferably less, up to about 30 ms.
I understand the ADC and ADC are sigma delta types which implies of group delay of a few ms. If this is too much the spin chip may not suit my purposes and I'll need a DSP with a different type (external) of ADC/DAC, of the type intended for servo control.
Can anyone tell me what the group delay of the spin's ADC and DAC?
Have any of you experimented with what I'm trying to do? i.e. A hybrid feedback loop with a digital delay combined with analog elements in the loop.
I want to experiment with a sort of Karplus system were the delay is supplied by a Spin chip but with other non-digital processing in the feedback loop but external to the Spin chip. Therefore the loop cycle time will include the conversion time of the ADC and DAC plus the variable digital delay of some algorithm in the chip plus any delay in the external analog circuit.
What I want to know is the time that the ADC and DAC conversion times will add to the loop as this will set the minimum loop time. Ideally I'd like to be able to vary the total delay in a range of about 1 to 2 ms and preferably less, up to about 30 ms.
I understand the ADC and ADC are sigma delta types which implies of group delay of a few ms. If this is too much the spin chip may not suit my purposes and I'll need a DSP with a different type (external) of ADC/DAC, of the type intended for servo control.
Can anyone tell me what the group delay of the spin's ADC and DAC?
Have any of you experimented with what I'm trying to do? i.e. A hybrid feedback loop with a digital delay combined with analog elements in the loop.