Charge sensitive preamplifier with pulsed source reset
AssigneeCanberra Industries, Inc.
InventorValentin T. Jordanov
Life of this patent
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Abstract
In a preferred embodiment, a charge sensitive preamplifier for a radiation detector, including: an amplifier having a JFET input (stage) and a capacitive feedback element, the amplifier producing an output voltage (pulse) proportional to a charge (pulse) deposited at the JFET input by the radiation detector; and circuitry connected to the amplifier output and to a source node of the JFET to provide to the source node a pulsed reset signal.
Claims22
A charge sensitive preamplifier for a radiation detector, comprising:
- (a) an amplifier having a JFET input stage and a capacitive feedback element, said amplifier producing an output voltage (pulse) proportional to a charge (pulse) deposited at said JFET input by said radiation detector;
- and
- (b) a circuitry connected to said amplifier output and to a source node of said JFET to provide to said source node a pulsed reset signal.
A method of operating a charge sensitive preamplifier for a radiation detector, comprising:
- (a) providing a JFET input stage;
- (b) providing an amplifier for connection to said JFET input stage to receive therethrough as an input a pulse output of said radiation detector and to provide a voltage output representative of said pulse output;
- and
- (c) providing to a source node of said JFET a pulsed feedback from said voltage output.
A charge sensitive preamplifier for a radiation detector, comprising:
- (a) an amplifier having a JFET input stage and a capacitive feedback element, said amplifier producing an output voltage (pulse) proportional to a charge (pulse) deposited at said JFET input by said radiation detector;
- (b) a circuitry connected to said amplifier output and to a source node of said JFET to provide to said source node a pulsed reset signal;
- (c) a first voltage source;
- and
- (d) a switch connected to said voltage source and to a source of said JFET and to ground, such as to forward bias a gate-source p-n junction of said JFET during reset and to ground said gate-source p-n junction of said JFET between resets.
A charge sensitive preamplifier for a radiation detector, comprising:
- (a) an amplifier having a JFET input stage and a capacitive feedback element, said amplifier producing an output voltage (pulse) proportional to a charge (pulse) deposited at said JFET input by said radiation detector;
- (b) a circuitry connected to said amplifier output and to a source node of said JFET to provide to said source node a pulsed reset signal;
- (c) said source of said JFET being parallely connected to a source capacitor, to a power MOSFET, and to a resistor connected to a MOS transistor;
- (d) a second power source connected to said MOS transistor;
- and
- (c) a pulse generator connected to said voltage output and to gates of said MOSFET and said MOS transistor.
A charge sensitive preamplifier for a radiation detector, comprising:
- (a) an amplifier having a JFET input stage and a capacitive feedback element, said amplifier producing an output voltage (pulse) proportional to a charge (pulse) deposited at said JFET input by said radiation detector;
- (b) a circuitry connected to said amplifier output and to a source node of said JFET to provide to said source node a pulsed reset signal;
- and
- (c) a voltage limiting element connected between a drain of said JFET and a fourth voltage source, such as to set JFET drain voltage during reset thereof.
Dependencies are inferred from the claim text.