Baseline restore sampling method

摘要

A baseline restore circuit includes a current input for receiving a current pulse having a DC current baseline; a charge amplifier having an input coupled to the current input, and an output referenced to a DC voltage baseline; a feedback baseline restore circuit comprised of a switched capacitor integration circuit having an input coupled to the output of the charge amplifier, and an output coupled to the current input; and a sample control circuit controlling the switched capacitor circuit input to the integrator so that only the reference voltage baseline is sampled. The inputs to the sample control circuit are a window comparator, and a high rate pulse detector, both with inputs from the charge amplifier output.

主权项

1. A baseline restore circuit comprising:
a current input for receiving a current pulse having a DC current baseline; a charge amplifier having an input coupled to the current input, and an output referenced to a voltage baseline; a switched capacitor circuit having an input coupled to the output of the charge amplifier, and an output; an integrator circuit having an input coupled to the output of the switched capacitor circuit and an output coupled to the current input; and a sample control circuit configured for selectively controlling the switched capacitor circuit so that only the charge amplifier output baseline is sampled, wherein the switched capacitor circuit comprises a capacitor referenced to the reference voltage baseline in series with a switch that performs a sample and hold of the charge amplifier output; and a switch that transfers the sampled voltage to the integrator input.