Patent ID: 8115152

Claim:
A read out circuit for generating an output signal indicative of the photonic energy absorbed by a photoconductor, the read out circuit including: (a) a biasing signal generator connected to apply an alternating current biasing signal to a first terminal of the photoconductor; (b) an input capacitor connected between a second terminal of the photoconductor and an input reference voltage, the connection between the second terminal of the photoconductor and the input capacitor defining an input node; (c) a charge transfer amplifier having an input connected to the input node and an output connected to a summing node, the charge transfer amplifier further including a demodulating transistor connected to receive a demodulating signal; (d) a charge collection circuit including a reset transistor connected to selectively couple the summing node to a supply voltage, and further including a summing capacitor connected to the summing node to store charge applied to the summing node; and (e) a sampling circuit including (i) a charge transfer arrangement connected between the summing node and an output node to selectively apply a charge from the summing node to the output node, (ii) a preset transistor connected to selectively couple the output node to the supply voltage, and (iii) an output capacitor connected to the output node to store charge applied to the output node.