I am working on an amplifier circuit with an OPAMP which only has positive voltage supplier, +15V. The input signal is a series of positive pulses with 2.5V DC offset. I would like to amplify the pulse itself and remove the DC offset, so that the output can be used to feed other logic circuit directly.
I appreciate if any one can give me any tip to accomplish it.
I need to explain more. The input signal comes from another charge amplifier which is powered by +15V also. So 2.5V DC offset is actually induced to make the charge amplifier working, and charging generated pulses should be very small. i would like to amplify the pulses, or pulse shaping to make full use of the dynamic range, then feed to an comparator/logic for processing.
I would not like to use comparator directly, since the dynamic range will be reduced dramatically. The schematic along with the expected output waveform are being attached.
I would not like to use comparator directly, since the dynamic range will be reduced dramatically. The schematic along with the expected output waveform are being attached.
Why do you say the dynamic range will be reduced? I thought you just wanted to convert the pulses to a standard logic level which a comparator will do.
Surely the pulses just need to be converted to a square-wave.
The DC can be removed with a decoupling capacitor and a transistor and pull-up resistor should do a good enough job of converting it to a squarewave. If you need it to be non-inverting, just use a NPN and PNP level shifter.
Why do you say the dynamic range will be reduced? I thought you just wanted to convert the pulses to a standard logic level which a comparator will do.
Theoretically, setting a threshold with a comparator can convert pulses to the standard logic. But the amplitude of pulses are small and varying. With environment changing (temperature etc), the DC offset and comparator threshold will drift, the amplitude of pulses will change also. To make the final output consistent, I prefer to enlarge the amplitude before going to the comparator.