amplifier circuit?
amplifier circuit?
(OP)
Hey Guys,
I need a circuit to do the following:
I have a signal which varies from 4.5 VDC to 5 VDC. I need it to transform it so it varies from 4.0 VDC to 5 VDC. Current is always below 10 mA. FYI: The signal is applied to a 12-bit A/D converter. I'm trying to increase the span of the signal to minimize mathematical rounding errors in a non-floating point processor (BS2e).
Anyone have any suggestions?
I need a circuit to do the following:
I have a signal which varies from 4.5 VDC to 5 VDC. I need it to transform it so it varies from 4.0 VDC to 5 VDC. Current is always below 10 mA. FYI: The signal is applied to a 12-bit A/D converter. I'm trying to increase the span of the signal to minimize mathematical rounding errors in a non-floating point processor (BS2e).
Anyone have any suggestions?





RE: amplifier circuit?
RE: amplifier circuit?
However, that is the range you have asked for so here goes... Skogs had said a gain of two and that is correct. Let’s assume you want a non-inverting gain of two. Ok then feed the input into the positive input of the opamp. Use say a 1K feedback resistor from the output to the negative input, then put a 1K resister from the negative input to a +5V reference voltage.
When you have 5V input, the other opamp input is also at 5V, so the output sits at 5V as required. When you put in 4.5V, that is a 0.5V drop from the previous situation, the output drops by double this amount because of the gain of two; hence the output is now 4.0V as required. Easy.
RE: amplifier circuit?
You guys got me thinking in the right direction - I had a serious case of mind block yesterday.