Disclosed are a charge sensitive amplifier capable of minimizing a variation in a signal voltage of an output signal by applying a bias direct current to a gate of a feedback transistor, and a radiation sensor including the same. According to the charge sensitive amplifier and the radiation sensor including the same, it is possible to minimize a variation in a signal voltage of a charge sensitive amplifier output signal by applying a current, which is formed by mirroring a current bias circuit designed to be insensitive to PVT variations, to a gate of a feedback transistor. Furthermore, it is possible to reduce a variation in charging time and enable high-speed sensing by charging the signal voltage to the level of a common voltage VCOM by using a constant current supplied through a bandgap reference (BGR) circuit.

It is described a charge preamplifier device (100) integrated in a chip (200) of semiconductive material comprising: an input (IN) for an input signal (i.sub.IN) and an output (OUT) for an output signal (v.sub.OUT); 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.sub.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).

It is described a charge preamplifier device (100) integrated in a chip (200) of semiconductive material comprising: an input (IN) for an input signal (i.sub.IN) and an output (OUT) for an output signal (v.sub.OUT); 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.sub.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).

A switched-capacitor amplifier includes a sampling capacitor, a first switch, a differential amplifier, a reference power supply, a second switch, a third switch, and a controller configured to execute on and off control of the first to third switches. The second switch includes a series circuit of first and second metal oxide semiconductor (MOS) transistors and a potential holding capacitor connected between a node that is a common connection point of the first and second MOS transistors and a ground.

An apparatus and method are provided for saturation prevention of a current integrator in a Resistive Processing Unit-based (RPU-based) accelerator. The apparatus includes a set of hardware switches. The apparatus further includes a voltage generator, operatively coupled between an input terminal and an output terminal of the current integrator, reducing a magnitude of an output voltage at the output terminal of the current integrator during a current integration operation by selectively applying a non-zero initial voltage to the current integrator prior to the current integration operation, responsive to an operating state of the set of hardware switches.

An apparatus and method are provided for saturation prevention of a current integrator in a Resistive Processing Unit-based (RPU-based) accelerator. The apparatus includes a set of hardware switches. The apparatus further includes a voltage generator, operatively coupled between an input terminal and an output terminal of the current integrator, reducing a magnitude of an output voltage at the output terminal of the current integrator during a current integration operation by selectively applying a non-zero initial voltage to the current integrator prior to the current integration operation, responsive to an operating state of the set of hardware switches.

A steering-wheel grip sensor includes: a driven electrode having a planar shape and extending along a rim of a steering wheel; a sensor electrode having a planar shape and opposed to the driven electrode; a sine-wave generator that supplies a sinusoidal voltage to the driven electrode; a charge amplifier that includes a feedback capacitive element, detects a change in an amount of charge generated according to capacitance of the sensor electrode, and outputs the change in the amount of charge as a change in a voltage; a multiplication processor that multiplies the sinusoidal voltage by an output voltage from the charge amplifier; an integrator that smooths, by integration, a result of multiplication by the multiplication processor; and a grip determiner that determines whether the steering wheel is gripped, according to a level of the result smoothed.

A steering-wheel grip sensor includes: a driven electrode having a planar shape and extending along a rim of a steering wheel; a sensor electrode having a planar shape and opposed to the driven electrode; a sine-wave generator that supplies a sinusoidal voltage to the driven electrode; a charge amplifier that includes a feedback capacitive element, detects a change in an amount of charge generated according to capacitance of the sensor electrode, and outputs the change in the amount of charge as a change in a voltage; a multiplication processor that multiplies the sinusoidal voltage by an output voltage from the charge amplifier; an integrator that smooths, by integration, a result of multiplication by the multiplication processor; and a grip determiner that determines whether the steering wheel is gripped, according to a level of the result smoothed.

The use of a capacitor (22) to serve as the principal impedance in a negative feed-back loop in a voltage amplifier component (21) of a trans-impedance amplifier and actively controlling the amount of charge accumulated within the capacitor appropriately to improve the responsiveness and/or dynamic range of the amplifier. A switch (25) is electrically coupled to the inverting input terminal of the voltage amplifier and electrically isolated from the output terminal (23) of the voltage amplifier. The output voltage of the amplifier is proportional to the accumulation of charge, and the switch is operable to ‘reset’ the charge/voltage on the feedback capacitor, as desired. This arrangement decouples the structure of the switch from the output port of the voltage amplifier, and so avoids leakage currents and/or interfering voltage signals emanating from the switch structure and being felt at the output port of the voltage amplifier.

The use of a capacitor (22) to serve as the principal impedance in a negative feed-back loop in a voltage amplifier component (21) of a trans-impedance amplifier and actively controlling the amount of charge accumulated within the capacitor appropriately to improve the responsiveness and/or dynamic range of the amplifier. A switch (25) is electrically coupled to the inverting input terminal of the voltage amplifier and electrically isolated from the output terminal (23) of the voltage amplifier. The output voltage of the amplifier is proportional to the accumulation of charge, and the switch is operable to ‘reset’ the charge/voltage on the feedback capacitor, as desired. This arrangement decouples the structure of the switch from the output port of the voltage amplifier, and so avoids leakage currents and/or interfering voltage signals emanating from the switch structure and being felt at the output port of the voltage amplifier.