Differential Charge Amplifier. This increase appears at the output substantially amplified and inverted. The amplifier is able to convert the very small charge stored within an in pixel capacitor to a voltage level that can be easily processed.
The input amplifier is a differential charge amplifier consisting of a dual low noise fet and two high gain ic operational amplifiers fig 1. Both stages use a ti ths4551 opamp. A charge pre amplifier and then a normal voltage opamp to do a bunch more amplification.
Integrating the charge pulses from the detector gives a translation of input pulse energy to a peak voltage output which can then be measured for each pulse.
Charge amplifiers are also used in the readout circuitry of ccd imagers and flat panel x ray detector arrays. A charge pre amplifier and then a normal voltage opamp to do a bunch more amplification. A charge amplifier uses the basic integrator topology i e a capacitor in the feedback path produces an output voltage that is proportional to the integral of the input current and a resistor in the feedback path prevents the amplifier from saturating. The amplifier is designed in two stages.
