摘要:
A method includes providing a wide bandgap semiconductor substrate that includes a first transistor and a second transistor defined thereon. The method also includes coupling the first transistor to the second transistor. The method further includes coupling a bias circuit to the first transistor and the second transistor and forming a junction therebetween. The method also includes coupling the first transistor to a first voltage source and coupling the second transistor to a second voltage source. The first voltage source and the second voltage source are configured to define a predetermined differential input voltage.
摘要:
A circuit for converting a charge signal into a binary format of output bits comprises: an integration circuit including an operational transconductance amplifier having an inverting input terminal and an output terminal, an integrating capacitor connected between the inverting input terminal and the output terminal, the integrating capacitor for storing a charge input selectively provided by a sensor diode; and a folding circuit having a fold capacitor, the fold capacitor switchably coupled either to a fold voltage source via a fold buffer for charging the fold capacitor to a predetermined fold charge value, or to the integrating capacitor for selectively removing at least a portion of the stored charge input.
摘要:
A radiation detector includes at least one multiple channel pixelated detector driven via a plurality of pixelated anode electrodes and at least one planar cathode electrode. Each detector is configured to reduce the number of active pixelated anode electrodes until a rate of events detected via at least one corresponding planar cathode electrode exceeds a preset threshold above a background count rate within a predetermined time period.
摘要:
An adaptive imaging system includes a detector receiving energy transmitted through a target and generating electrical charge pulses at a pulse rate indicative of an intensity of received energy. The system also includes a switch for selectively coupling the charge pulses from one or more pixel elements of the detector to a charge pulse counter for counting the charge pulses and a charge pulse integrator for integrating the charge pulses. In addition, the system includes a prediction module for predicting a charge pulse rate expected to be produced by the detector and for operating the switch to selectively couple the charge pulses to the counter and the integrator responsive to a predicted charge pulse rate.
摘要:
An analog to digital conversion circuit includes a first circuit (10) for receiving an analog signal (16) applied to an input (e.g., 26) of the first circuit via a connection to an analog source (e.g., 18) and generating a first residue (58) of the analog signal at an output (e.g., 32). The first circuit may be selectively configurable in a first mode for integrating the analog signal to generate an integrated analog signal and configurable in a second mode for disconnecting the first circuit from the analog source while folding the integrated analog signal to generate the first residue. The analog to digital conversion circuit also includes a second circuit (60) coupled to the output of the first circuit for resolving the first residue provided by the first circuit and for generating a further resolved second residue (98).
摘要:
A multi-channel analog to digital conversion circuit and methods thereon are provided. The multi-channel analog to digital conversion cirucit comprises a plurality of linearized channels wherein each channel comprises a multi-stage pipelined charge-to-digital converter and an integrating capacitor within each stage of the multi-stage converter wherein analog residue is processed by subsequent analog to digital converter stages. Each stage of respective linearized channels is configured for calculating gain and offset for each stage in the channel and such gain and offset is used in subsequent integration periods.
摘要:
A sensing circuit for a triac dimmable gas discharge lamp ballast uses the duty cycle of the output waveform of a conventional triac dimmer as the parameter representing a set point for controlling the degree of clamping applied to the ballast circuit, and thus the amount of light produced by a fluorescent lamp. The sensing circuit may include a comparator that receives a rectified output waveform of a triac dimmer and produces output pulses corresponding in width to the duty cycle of the waveform, and a capacitor averaging the values of the pulses produced by the comparator to produce a set point signal representing a dimming level of the lamp. A triac dimmable ballast circuit using this sensing circuit has reduced sensitivity to line voltage and a wide mechanical range over which the light level of the fluorescent lamp is controlled by the user. The sensing circuit also enables a preheat timing circuit that eliminates the timing capacitor of prior art preheating circuits. A gas discharge lamp ballast and a method for its operation are also disclosed.
摘要:
An analog to digital conversion circuit for converting an analog input signal into a plurality of binary output bits includes an operational amplifier and an integrating capacitor for storing a charge proportional to the integral of the input signal. A charge subtracting circuit removes a first predetermined charge from the integrating capacitor when an output charge of the operational amplifier is substantially equal to a second predetermined charge. The first predetermined charge level is removed from the integrating capacitor a number of times. The removal of the first predetermined charge from the integrating capacitor allows the integral of the analog input signal to be larger than a maximum charge capable of being stored by the integrating capacitor. A digital logic circuit tracks the number of times that the first predetermined charge is removed from the integrating capacitor by the charge subtracting circuit, and the digital logic circuit provides at least one bit of the plurality of binary output bits. A residue quantizing circuit determines a residual charge in the integrating capacitor and provides at least one additional bit of the plurality of binary output bits corresponding to the residual charge. The residual charge is substantially equal to a stored charge in the integrating capacitor after the first predetermined charge has been removed the number of times.