I could not type any info in Chrome!
Anyway... does anybody know of a block similar to that in AN60321 for PSoC1 devices?
Why not create a S/H driven by a comparator. Use a open drain output to discharge
cap to start a new cycle.
Or use a SC block.
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Or use DAC, Comparator in a control loop and do a binary search on
DAC to create the trip point for the Comparator.
Thanks Dana, All have been considered, BUTTTT... the signal in fact two signals are AC waveforms and would require more analogue blocks then are available on the PSoC1. OK on the PSoC3 or 5 device with the user block but the IC format is better for me with a PDIP device. I will continue to investigate. Regards
There are as many as 12 analog blocks on PSOC 1, that still not
Using a dual ADC and extending the AGND to a pin uses 3 analogue columns and I have yet to integrate the waveform for peak detection. No project to post yet, I am in the planning phase.
At its simplest a diode (schottky) and a cap form a peak detector. Use an open drain
output to discharge cap on reset command.
In this case the Vf of the diode essentially eliminated. Again open drain output can
effect reset (cap discharge) switch.
You can make the opamp from an SC block per the method of AN2223. The problem is that the SC block inputs have finite input impedance, so this might load down your hold capacitor. This can be handled by using a PGA with gain of unity to buffer the B-input of the block. Instead of using P2.3 directly into the SC block, the inverting input is through P0.odd through a PGA in ACB00, then into the B input of the SC block in ASC10. The output isn't low impedance because of the diode, you might want to buffer it with another PGA placed in ACB01. This isn't blinding fast, the net opamp is about half of the speed of the venerable 741.
Certainly that would work. The prior approaches discussed all have tradeoffs,
this one would impact available MIPs which would be very dependent on
max frequency of waveform.
Consider posting your whole project, makes life easier to troubleshoot. We can't open just
the .cmx file by itself.
I have found the problem. Analogue input muxes connected to the same source. OOPS!