Hello all,
I am designing a signal conditioning circuit for a load cell.
I need to offer programmable gain for the input stage instrumentation amplifier. Its a standard instrumentation amplifier with the gain equation given by G = 1 + (50000/Rg). The input to the instrumentation amp is a bipolar differential +/- 10 mV signal. The gains are in the region of 100 to 400. So the voltage at the output of the instrumentation amplifier is in the range of 0 to +/- 1V or +/-4V. But in reality the signal will be unipolar in nature due to the fact that the dead weight of the weighing pan will always place the signal in the positive quadrant.
My question is Can I use a single supply analog switch for the gain selection or do I need to use a dual supply one? Any help would be highly appreciated.
I am attaching an image file showing the proposed scheme for the gain selection for the instrumentation amplifier.
I also have downstream amplifiers that boost the signal to about 7.5 V. Would the mux/switch used for the gain selection for the downstream amp have to be dual supply or single supply and what voltage?
Thanks
regards
Anand
I am designing a signal conditioning circuit for a load cell.
I need to offer programmable gain for the input stage instrumentation amplifier. Its a standard instrumentation amplifier with the gain equation given by G = 1 + (50000/Rg). The input to the instrumentation amp is a bipolar differential +/- 10 mV signal. The gains are in the region of 100 to 400. So the voltage at the output of the instrumentation amplifier is in the range of 0 to +/- 1V or +/-4V. But in reality the signal will be unipolar in nature due to the fact that the dead weight of the weighing pan will always place the signal in the positive quadrant.
My question is Can I use a single supply analog switch for the gain selection or do I need to use a dual supply one? Any help would be highly appreciated.
I am attaching an image file showing the proposed scheme for the gain selection for the instrumentation amplifier.
I also have downstream amplifiers that boost the signal to about 7.5 V. Would the mux/switch used for the gain selection for the downstream amp have to be dual supply or single supply and what voltage?
Thanks
regards
Anand