Solid-state charge detector
AssigneeBrigham Young University
InventorsYixin Song, Shiuh-hua Wood Chiang, Aaron R. Hawkins, Daniel E. Austin
Life of this patent
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Abstract
The present invention is a system and method for providing a charge detector that utilizes small feedback capacitors in a low-noise, high-gain, system that combines a differential topology in a solid-state amplifier implemented in a complementary metal-oxide semiconductor (CMOS) process with active reset, thereby achieving high dynamic range and robust operations. A custom optoelectronic system is used to measure gain, and while operating at a sampling frequency of 10 kHz, the active reset extends the dynamic range of the charge detector.
Claims42
A method for operating a low power, differential, solid-state charge detector with active reset, said method comprised of:
- providing a charge collector;
- providing a charge amplifier having differential inputs to thereby reduce sensitivity to noise and interference, wherein the charge collector is coupled to the charge amplifier;
- providing a first feedback capacitor in parallel with a feedback resistor on each of the differential inputs of the charge amplifier, wherein the first feedback capacitor is less than 50 fFarads;
- providing an active reset switch on the differential inputs for performing an active reset of the charge amplifier;
- providing a common mode feedback circuit coupled to both outputs of the charge amplifier;
- resetting the charge amplifier using the active reset switch;
- and
- measuring the charge on the charge collector over a period of time at the outputs of the charge amplifier.
A low-power, differential, solid-state charge detector with active reset, said detector comprised of:
- a charge collector;
- a charge amplifier having differential inputs and two outputs, wherein the charge collector is coupled to the charge amplifier;
- a first feedback capacitor in parallel with a feedback resistor on each of the differential inputs of the charge amplifier, wherein the first feedback capacitor is less than 50 fFarads;
- an active reset switch on the differential inputs for performing an active reset of the charge amplifier;
- and
- a common mode feedback circuit coupled to both outputs of the charge amplifier.
A method for operating a low power, differential, solid-state charge detector with active reset, said method comprised of:
- providing a charge collector;
- providing a charge amplifier having differential inputs with transistors to thereby reduce sensitivity to noise and interference, wherein the charge collector is coupled to the charge amplifier;
- providing a first feedback capacitor in parallel with a feedback resistor on each of the differential inputs of the charge amplifier, wherein the first feedback capacitor is less than 50 fFarads;
- optimizing the differential input transistors of the charge amplifier to thereby decrease the noise of the charge detector;
- providing an active reset switch on the differential inputs for performing an active reset of the charge amplifier;
- providing a common mode feedback circuit coupled to both outputs of the charge amplifier;
- resetting the charge amplifier using the active reset switch;
- and
- measuring the charge on the charge collector over a period of time at the outputs of the charge amplifier.
A low-power, differential, solid-state charge detector with active reset, said detector comprised of:
- a charge collector;
- a charge amplifier having differential inputs and two outputs, wherein the charge collector is coupled to the charge amplifier, wherein the differential inputs are comprised of two differential transistors, and selecting a transistor width, a transistor length and a transistor tail current of the differential input transistors that generates the lowest noise from the charge amplifier;
- a first feedback capacitor in parallel with a feedback resistor on each of the differential inputs of the charge amplifier, wherein the first feedback capacitor is less than 50 fFarads;
- an active reset switch on the differential inputs for performing an active reset of the charge amplifier;
- and
- a common mode feedback circuit coupled to both outputs of the charge amplifier.
Dependencies are inferred from the claim text.