Patent ID: 6323730
Filing Date: 2001-11-27
Classification: H03F

Abstract:
A charge sensitive preamplifier, comprising:a first operational amplifier (9a) having a first non-inverting input, a first inverting input and a first output, said first operational amplifier operatively arranged to amplify an input charge signal and provide an output signal;a common drain differential amplifier (8) having a common drain non-inverting input and a common drain inverting input and a common drain output, said common drain output coupled to said first non-inverting input and said first inverting input, respectively, of said first operational amplifier; and,a second operational amplifier (9b) having a second inverting input coupled to said first output of said first operational amplifier, and having a second output coupled to said common drain inverting input of said common drain differential amplifier, said second operational amplifier operatively arranged to dynamically bias said common drain differential amplifier to produce zero current continuously into said common drain inverting input of said common drain differential amplifier.