Charge-sensitive amplifier

摘要

A charge-sensitive amplifier is disclosed for use in amplifying signals from a particle detector. This includes a field effect transistor having a gate, source and drain, the gate being connectable, using a gate pad, to the particle detector, for the receipt of said signals. Also included is an amplifier having an input connected to the drain or source of the field effect transistor and an output connected through a feedback capacitor to the gate of the field effect transistor. The gate pad of the field effect transistor is made to be integral with the feedback capacitor so as to reduce the capacitance of the device.

主权项

1. A charge-sensitive amplifier for use in amplifying signals from a discrete particle detector, the charge--sensitive amplifier comprising:
a field effect transistor for the receipt of said signals having a gate, source and drain, the gate having a gate bond pad that is connectable to the discrete particle detector via a wire bond connection; an amplifier having an input connected to the drain or source of the field effect transistor and an output connected through a feedback capacitor to the gate of the field effect transistor, characterised in that the plate of the feedback capacitor that is connected to the output electromagnetically shields part of a substrate electrically connected to signal ground such that parasitic capacitance attributable to the gate bond pad is effectively removed or made substantially less than capacitance attributable to the feedback capacitor.