Abstract:
A charge sensing circuit according to the present invention includes a photodiode, an operational amplifier, a feedback capacitor, a leakage path transistor for allowing DC leakage current to flow from the photodiode, and a current generating unit for providing drive current. Since a drain and a source are connected between the photodiode and a negative input terminal of the operational amplifier and a power source, and also connected to allow a gate voltage to be determined by the voltage at both ends of a current source transistor where some of the drive current flows and a compensation capacitor, the leakage path transistor may effectively leak a DC leakage current occurring at the photodiode. The current generating unit may stably generate drive current against voltage and temperature variation because it includes a source degeneration resistance.
Abstract:
A charge pump for generating an input voltage for an operational amplifier includes a storage capacitor for storing a charge pump voltage and a flying capacitor configured to be charged during a first phase of operation and discharged during a second phase of operation. As the flying capacitor is discharged, it charges the storage capacitor. A current source is coupled to the flying capacitor and a switching means is provided for switching current from the current source through the flying capacitor in a first direction during the first phase and in a second direction opposite to the first direction during the second phase.
Abstract:
A dual integrator system (200) comprises two integrators (220A-B), an output stage (270), and a switching network (240 A-D). The first and second integrators receive a differential Hall sensor signal (205, 210) and a reference voltage (210). The first integrator outputs a first integrator signal (225A) based on the differential Hall sensor and the reference voltage. The second integrator outputs a second integrator signal (225B) based on the differential Hall sensor signal and the reference voltage. The first integrator comprises a first offset cancellation feedback loop (235 A), and the second integrator comprises a second offset cancellation feedback loop (235B). The switching network is coupled to the first and second integrators and to the output stage, and alternates which of the first and second integrators is coupled to the output stage. In some embodiments, the first and second integrators each perform a reset operation, a sampling operation, an integration operation, a differential to single-ended conversion operation, and a holding operation.
Abstract:
A charge preamplifier device (100) integrated in a chip (200) of semiconductive material comprising: an input (IN) for an input signal (ii N ) and an output (OUT) for an output signal ( VOUT ); a substrate (202) of semiconductive material doped according to a first type of conductivity; an electrically insulating layer (204) placed on said substrate (202); a feedback capacitor (C f ) integrated in the chip (200) and comprising a first electrode (3) connected to the input (IN) and a second electrode (2) connected to the output (OUT). The second electrode (2) is formed by a doped conductive region (205) having a second type of conductivity, opposite to the first type of conductivity, and integrated in the substrate (202) in order to face the first electrode (3).
Abstract:
Reducing a sensitivity of an electromechanical sensor is presented herein. The electromechanical sensor comprises a sensitivity with respect to a variation of a mechanical-to-electrical gain of a sense element of the electromechanical sensor; and a voltage-to-voltage converter component that minimizes the sensitivity by coupling, via a defined feedback capacitance, a positive feedback voltage to a sense electrode of the sense element - the sense element electrically coupled to an input of the voltage-to-voltage converter component. In one example, the voltage-to-voltage converter component minimizes the sensitivity by maintaining, via the defined feedback capacitance, a constant charge at the sense electrode. In another example, the electromechanical sensor comprises a capacitive sense element comprising a first node comprising the sense electrode. Further, a bias voltage component can apply a bias voltage to a second node of the electromechanical sensor. In yet another example, the electromechanical sensor comprises a piezoelectric sense element.
Abstract:
The present invention relates to the resistorless charge sensitive preamplifier system for amplifying charge delivered by a particle detector (Ge), comprising: a field effect transistor (T1) having a gate, source and drain, the gate being connectable to the particle detector (Ge), for the receipt a signal from particle detector (Ge); an amplifier (OA) having an input connected to the drain or source of the field effect transistor (T1) and an output connected through a feedback capacitor (CF) to the gate of the field effect transistor (T1), in which system further comprising low frequency feedback realized with a field effect transistor (T2) having gate shorted with gate of field effect transistor (T1).
Abstract:
The present invention relates to a linear, high sensitivity, high speed trans- impedance amplifier (TIA) which allows a large dynamic range of input current up to very large values, maintains high linearity and keeps constant output voltage, maintains the same frequency response across the full gain control range, provides very high input sensitivity and large bandwidth, and allows input current monitoring without affecting input sensitivity. In other words, the novel circuit disclosed herein provides for the feedback path to maintain the same level of feedback even while the output signal is varied. This allows a wide and stable bandwidth, as well as a monitor to be placed in the TIA.