Noway2,
Thanks for your insight. Sorry for not addressing your question. This could be done in software and that is a good suggestion. I would however like to avoid that approach. I don't consider any of the circuitry that I've presented to be complex, and certainly not enough to justify...
One idea I have is to duplicate the integrator with a unity gain inverting amplifier on the input. I can use a dual analog switch for the resets and a dual channel ADC to monitor both outputs simultaneously. The dual switch and triple (most likely quad) op amp packages don't add too much to...
xray,
Sorry to be confusing but fig. 2 is the original circuit I built before attempting any bi-polar stuff. It has a 0 volt bias. The traces in fig. 1 are actual measurements from that circuit, and you are correct with your interpretation.
I can add a negative supply rail to that circuit...
The positive and negative signals are both important. So, this being the case I do care which side of zero it's on since it will indicate the polarity of the process variable. Think positive and negative pressure or flow. This is simply the way the transducer outputs the signal. I'm a little...
Hello all,
I have a signal, of which the integral represents a process variable. (Fig. 1 of references.pdf) I designed a gated integrator (Fig. 2) to isolate the usable portion of the signal. I then sample this output with an ADC and scale appropriately. This works well, however the input...
I never really payed much attention to the Qgd value and now it's come back to bite me! It turns out that Vishay has some parts with a low Qgd with slight Rds(on) and Id trade offs. Neither should matter in this application. I may also try one of the small package analog switches just for...
Hello all,
I designed a gated integrator circuit. The first version worked well. I used an analog MUX for the gate (reset) switch. I figured the same thing could be done for less cost and using less board real estate by replacing the MUX with a MOSFET. When using the MOSFET, the integrator...
