Hi there,
I hope someone can help me. I'm running some simulations with TINA using the SPICE model for the ACF2101 switched Integrator from the TI website. So far I've been able to get the circuit to integrate the input current and to switch the output on and off using the select port.
The problems I'm having are that toggling the HOLD switch does not seem to have any effect on the output. I would expect the output to remain more or less stable (capture and hold behaviour) when the hold pin is toggled however the signal is unaffected in either case. I have tried every combination of the RESET, SELECT and HOLD pins however none seems to work.
A bit of background might be interesting and/or helpful. I'm trying to design a circuit to measure the light transmitted through a medium. The idea is to have a transmitting led in on one side and have it pulse. The sensing LED is placed on the other side of the medium and a circuit will integrate the signal it receives. After a LED on period the signal from the sensing LED will be held and a second integrator will be used to measure the signal when de signal LED is off. The final output signal will be the difference between the LED on and LED off signal. I think the ACF2101 would be ideal for this measurement.
I have attached a ZIP file containing following files:1) A figure with the TINA schematic I use.2) A plot of the values of interest from a transient analysis. This also shows all the combinations of the RESET, SELECT and HOLD pin I tried.3) The TINA schematic file.Any insight into why the HOLD pin is not functioning will be greatly appreciated.Regards,