Some considerations -
1) TIA may have be offset to handle fact it is inverting. Or change
polarity of IDAC.
2) TIA conversion R tolerance is 60%, you will have to factor that in
to determining amplitude range you will get.
3) You need to calc slew rate needed for 160 Khz and pk-pk range
you want. The basic PSOC OpAmp (used in TIA) ranges from .9 to
4) You have to manage compliance range of IDAC in your calculations.
5) Consider terminating IDAC with a low R like a K or so, then buffering
that pin with an OpAmp.
6) At 160 Khz, N samples/period, your table lookup loop has to run at
N x 160 Khz, just a consideration.
Hi Thanks all for your swift response.
If you want a 1V sine pk-pk at 160 Khz, 32 samples, you will see you can't
do it with WaveDAC8 because of settling time of VDAC. In fact you either have
to drop Fsamp by ~ 5 or the # samples by ~ 5, translate lots of distortion. And you are
right up against the slew rate of the OpAmp in WaveDAC8. In fact if you terminate
the IDAC externally with a low Z R (to get fast setltling time) you still have to go thru
OpAmp to buffer, or live with terminating R as your output Z for the sine gen.
Do the calculations.
Many thanks to your reply.
Do you think the following will work.
Instead of using the internal components of PSOC 5 to buffer, can I used external components, including resistor and high speed trans-impedance amplifier to perform the current to voltage conversion?