Abstract: The subject matter of the invention is an active pixel dental radiological image sensor, with integrated X-ray occurrence detection, which uses the pixels of the matrix to detect the start of an X-ray flash, by detecting the current produced by all the photodiodes in the matrix. A switching circuit MUX1 thus allows, in a first phase of detecting the start of an X-ray flash, a common connection node NC to be connected that corresponds to the drain of a photodiode initialisation transistor M1 at the input of a current-voltage conversion detection circuit DTX1, which provides as output a signal for detecting the start of an X-ray flash when the current produced by all the photodiodes of the matrix exceeds a predetermined threshold. The switching circuit MUX1 is then controlled to connect the common connection node NC of the pixels to a photodiode re-initialisation voltage source, VRS.

Abstract: The subject matter of the invention is an active pixel dental radiological image sensor, with integrated X-ray occurrence detection, which uses the pixels of the matrix to detect the start of an X-ray flash, by detecting the current produced by all the photodiodes in the matrix. A switching circuit MUX1 thus allows, in a first phase of detecting the start of an X-ray flash, a common connection node NC to be connected that corresponds to the drain of a photodiode initialisation transistor M1 at the input of a current-voltage conversion detection circuit DTX1, which provides as output a signal for detecting the start of an X-ray flash when the current produced by all the photodiodes of the matrix exceeds a predetermined threshold. The switching circuit MUX1 is then controlled to connect the common connection node NC of the pixels to a photodiode re-initialisation voltage source, VRS.

Abstract: A circuit (300) for detecting the appearance of x-rays with a view to triggering a radiological image capture, comprising a set (301) of photodiodes that is connected to a ground (GD), an amplifying circuit (302) and a capacitor (C2), the amplifying circuit (302) comprising an amplifier (AMP) and a voltage source (GEN) and being connected, via a first input, to the output of the set (301) of photodiodes, the capacitor (C2) being connected between the ground (GD) and a second input of the amplifier (AMP), the detecting circuit (300) being characterized in that the amplifying circuit (302) is configured to carry out in succession the steps of: Charging the capacitor (C2) with a reference voltage (Vref) generated by the voltage source (GEN); Isolating the second input of the amplifier (AMP) from the voltage source (GEN); and Integrating the current generated by the set (301) of photodiodes.

Abstract: A circuit (300) for detecting the appearance of x-rays with a view to triggering a radiological image capture, comprising a set (301) of photodiodes that is connected to a ground (GD), an amplifying circuit (302) and a capacitor (C2), the amplifying circuit (302) comprising an amplifier (AMP) and a voltage source (GEN) and being connected, via a first input, to the output of the set (301) of photodiodes, the capacitor (C2) being connected between the ground (GD) and a second input of the amplifier (AMP), the detecting circuit (300) being characterized in that the amplifying circuit (302) is configured to carry out in succession the steps of: Charging the capacitor (C2) with a reference voltage (Vref) generated by the voltage source (GEN); Isolating the second input of the amplifier (AMP) from the voltage source (GEN); and Integrating the current generated by the set (301) of photodiodes.

Abstract: The invention relates to medical imaging and, more specifically, to intraoral dental radiology. The sensor according to the invention includes a series (SPHx) of detection photodiodes for detecting the arrival of an X-ray flash. The series of photodiodes occupies the location of a central column of the matrix of pixels. The signal of the missing pixel in each row can be reconstructed by interpolating the signals provided by the adjacent pixels of the row. The detection photodiodes are identical to the photodiodes of the active CMOS pixels. They are all electrically connected on one side to a reference potential and on the other side to a detection conductor (CD) extending along the series of photodiodes. This detection conductor is connected to a detection circuit (DX) delivering a signal for triggering the capture of an image when the detected current or the variation in this current exceeds a threshold showing that an X-ray flash has been initiated.

Abstract: The invention relates to medical imaging and, more specifically, to intraoral dental radiology. The sensor according to the invention includes a series (SPHx) of detection photodiodes for detecting the arrival of an X-ray flash. The series of photodiodes occupies the location of a central column of the matrix of pixels. The signal of the missing pixel in each row can be reconstructed by interpolating the signals provided by the adjacent pixels of the row. The detection photodiodes are identical to the photodiodes of the active CMOS pixels. They are all electrically connected on one side to a reference potential and on the other side to a detection conductor (CD) extending along the series of photodiodes. This detection conductor is connected to a detection circuit (DX) delivering a signal for triggering the capture of an image when the detected current or the variation in this current exceeds a threshold showing that an X-ray flash has been initiated.

Abstract: The invention relates to a memory point of SRAM (static memory) type memory. The memory point conventionally comprises two inverters mounted head-to-tail between two nodes, and at least one access transistor able to be made conductive during a writing phase and linked between a first node and a line of data to be written, characterized in that it comprises an isolating transistor inserted in series between the output of a first inverter and the first node, the isolating transistor being controlled by an insulation signal at the start of a writing phase. The current consumption is reduced when the state of the memory point has to be inverted.

Abstract: A single-ended sense amplifier having a precharge circuit for maintaining a stable voltage on a bitline, and a sensing circuit coupled to the bitline for sensing an amount of current flowing into the bitline. To sense multiple current levels and multiple stored bits per memory cell, multiple direct current amplification circuits are electrically coupled to the sensing circuit for amplifying the current sensed on the bitline, multiple current-to-voltage conversion circuits for converting a sensed current to a voltage, and a multiple voltage amplification or inverter circuits for amplifying the voltage and detecting a multitude of current levels. The multitude of current levels are converted or decoded into multiple bits. The sense amplifier can be implemented using standard CMOS components and provides improved access time at low power supply voltage, high robustness to process variations, and the ability to sense very low currents.

Abstract: A single-ended sense amplifier having a precharge circuit for maintaining a stable voltage on a bitline, and a sensing circuit coupled to the bitline for sensing an amount of current flowing into the bitline. To sense multiple current levels and multiple stored bits per memory cell, multiple direct current amplification circuits are electrically coupled to the sensing circuit for amplifying the current sensed on the bitline, multiple current-to-voltage conversion circuits for converting a sensed current to a voltage, and a multiple voltage amplification or inverter circuits for amplifying the voltage and detecting a multitude of current levels. The multitude of current levels are converted or decoded into multiple bits. The sense amplifier can be implemented using standard CMOS components and provides improved access time at low power supply voltage, high robustness to process variations, and the ability to sense very low currents.

Abstract: A single-ended sense amplifier having a precharge circuit for maintaining a stable voltage on a bitline, a sensing circuit coupled to the bitline for sensing an amount of current flowing into the bitline, a direct current amplification circuit electrically coupled to the sensing circuit for amplifying the current sensed on the bitline, a current-to-voltage conversion circuit for converting the sensed current to a voltage and a voltage amplification circuit for amplifying the voltage at the sense amp output. The sense amplifier can be implemented using standard CMOS components and provides improved access time at low power supply voltage, high robustness to process variations, and the ability to sense very low currents.