929 results about "Transimpedance amplifier" patented technology

A pulse monitoring plethysmograph system for establishing a history of the pulses of the user over an extended period of time, comprises a housing, a piezoelectric sensing element mounted within said housing, and fixed to the housing, a force transmitting member positioned to cause said piezoelectric sensing element to flex in response to an external force and to generate a current, and a transimpedance amplifier. The transimpedance amplifier converts the current generated by the flexing of the piezoelectric element into a voltage signal and an analog to digital converter converts the voltage signal into digital data. A digital memory storing member is provided for storing the digital data and establishing a history of data over an extended period of time.

The invention concerns a conditioning circuit (10) for an external signal (IN) representative of a physiological quantity, arranged between an optical sensor (11) and a processing unit (12), the received external signal (IN) being broken down into a useful component and an ambient component, characterized in that the conditioning circuit includes a first stage (13) including a transimpedance amplifier with an incorporated high pass filter (15) using a feedback loop to subtract the ambient signal component from the received external signal, and to deliver at output an amplified useful signal (IN1), a second stage (16) including a blocker sampler circuit (17) for demodulating the amplified useful signal and delivering at output a demodulated useful signal (IN2), and a third stage (18) including a bandpass filter (19) for filtering the demodulated useful signal in the frequency band of the physiological quantity to be detected and for transmitting a conditioned signal (OUT) to the processing unit.

An assembly is provided that may be used in high data rate optical communications, such as free-space communication systems. The assembly may include a main optical receiver element and a lenslet array or other optical element disposed near the focal plane that collects an optical signal and focuses that signal as a series of optical signal portions onto a photodetector array, formed of a series of InGaAs photodiodes, for example. The electrical signals from the photodetectors may be amplified using high bandwidth transimpedance amplifiers connected to a summing amplifier or circuit that produces a summed electrical signal. Alternatively, the electrical signals may be summed initially and then amplified via a transimpedance amplifier. The assembly may be used in remote optical communication systems, including free-space laser communication environments, to convert optical signals up to or above 1 Gbit/s or higher data rates into electrical signals at 1 Gbit/s or higher data rates.

An inductive proximity sensor is disclosed. The proximity sensor includes a resonator with a bifurcated inductance coupled to a plurality of transimpedance amplifiers. A portion of the resonator is configured to generate eddy currents in a target containing metal. In various embodiments, the transimpedance amplifiers provide signals associated with eddy currents to a synchronous detector. Apparatus and methods for operating the inductive proximity sensor are disclosed.

The embodiment of the invention discloses an overcurrent protection circuit, and the circuit comprises a level converter and a substrate array line drive (GOA) circuit in electrical connection with the level converter. The circuit also comprises a current detection circuit, a current-voltage converter, a voltage comparator, a timer control register, and a logic gate circuit. The GOA circuit is connected with the current detection circuit, and the current detection circuit is connected with the current-voltage converter. The current-voltage converter is connected with the in-phase input end of the voltage comparator, and the inverted-phase input end of the voltage comparator is connected with a reference voltage. The output end of the voltage comparator is connected with the input end of the timer control register and the first input end of the logic gate circuit. The output end of the timer control register is connected with the second input end of the logic gate circuit. The output end of the logic gate circuit is connected with the level converter. According to the embodiment of the invention, the circuit can prevent the wrong triggering of an overcurrent protection operation. The invention also provides a liquid crystal display comprising the circuit.

Signals from an imager pixel photodetector are received by an amplifier having capacitive feedback, such as a capacitive transimpedance amplifier (CTIA). The amplifier can be operated at a low or no power level during an integration period of a photodetector to reduce power dissipation. The amplifier can be distributed, with an amplifier element within each pixel of an array and with amplifier output circuitry outside the pixel array. The amplifier can be a single ended cascode amplifier, a folded cascode amplifier, a differential input telescopic cascode amplifier, or other configuration. The amplifier can be used in pixel configurations where the amplifier is directly connected to the photodetector, or in configurations which use a transfer transistor to couple signal charges to a floating diffusion node with the amplifier being coupled to the floating diffusion node.

A receiver (200) includes a transconductance mixer (310), a polyphase filter (320), and a transimpedance amplifier (330). The transconductance mixer (310) mixes a radio frequency (RF) voltage signal into a current signal having a plurality of phases using a local oscillator signal. The polyphase filter (320) filters the current signal to provide a filtered current signal. The transimpedance amplifier (330) converts the filtered current signal into an output voltage signal.

An apparatus comprising a first amplifier circuit, a detect circuit, a control circuit and a second amplifier circuit. The first amplifier circuit may be configured to generate an amplified signal in response to an input signal. The detect circuit may be configured to generate a feed-forward signal in response to the amplified signal. The control circuit may be configured to generate a dynamic control signal in response to the feed-forward signal. The second amplifier circuit may be configured to generate an output signal in response to (i) the amplified signal and (ii) the dynamic control signal. The control circuit may be configured to control a gain of the second amplifier circuit by adjusting a magnitude of the dynamic control signal.

A transimpedance amplifier (TIA) circuit according to the present invention includes a first opamp having an input and an output. A second opamp has an input that communicates with the first opamp and an output. A first feedback path communicates with the input and the output of the first opamp and includes a first resistance. A second feedback path communicates with the input and the output of the second opamp and includes a second resistance. A third feedback path communicates with the input of the first opamp and the output of the second opamp.

Disclosed is a front end circuit involving a transimpedance amplifier that drives a resistor, thereby lowering the input impedance of the circuit by dividing the feedback resistance by the gain of the amplifier. In the front end circuit of the present invention, a first transistor is coupled in series with a resistor, where the received signal is input to a base or gate of the first transistor and the amplified received signal is recovered from a collector or drain of the first transistor such that the first transistor and resistor provide the gain of the front end circuit. A second transistor has an emitter or source coupled to the base or gate of the first transistor. A base or gate of the second transistor is coupled to the collector or drain of the first transistor and a collector or drain of the second transistor is coupled to a power supply rail. The second transistor thus provides the feedback path for the transimpedance amplifier thereby reducing the input impedance of the circuit.

A quad photoreceiver includes a low capacitance quad InGaAs p-i-n photodiode structure formed on an InP (100) substrate. The photodiode includes a substrate providing a buffer layer having a metal contact on its bottom portion serving as a common cathode for receiving a bias voltage, and successive layers deposited on its top portion, the first layer being drift layer, the second being an absorption layer, the third being a cap layer divided into four quarter pie shaped sections spaced apart, with metal contacts being deposited on outermost top portions of each section to provide output terminals, the top portions being active regions for detecting light. Four transimpedance amplifiers have input terminals electrically connected to individual output terminals of each p-i-n photodiode.

The invention discloses a method for integrating focusing and detection of cells and a miniaturized system thereof. The miniaturized system comprises a microfluidic chip, a data acquisition card, a miniature computer and a sample injection device, wherein the microfluidic chip is formed by a flow channel layer, a substrate layer and a PCB (Printed Circuit Board) which are aligned and packaged in sequence; the flow channel layer is provided with an asymmetric sinusoidal flow channel, a detection main flow channel, polyelectrolyte gel and a conductive-fluid storage pool; the polyelectrolyte gel, the conductive-fluid storage pool and a silver-silver chloride wire form a detection electrode; the silver-silver chloride wire is connected with the data acquisition card and the miniature computer by a transimpedance amplifier and a differential amplifier so as to form a differential impedance detection circuit of the cells; the miniature computer is used for realizing generation of pseudorandom excitation signals, processing of system response signals and analysis and display of multi-performance parameters of the cells. The method and the miniaturized system disclosed by the invention integrate the functions of focusing and detection of the cells, realizes miniaturization and portability of the system and can be widely used for biological study of blood cells and rare cells.

A bandwidth adjustable transimpedance amplifier. The bandwidth adjustable transimpedance amplifier includes a feedback path with a selectable resistance. The bandwidth adjustable transimpedance amplifier is preferably implemented with a photodiode in a five pin package for an optical transceiver system, with a single pin providing a monitor out function and a rate select input.

A receiver optical subassembly (ROSA) includes a photodetector array and a transimpedance amplifier (TIA) array. In each data channel, the photodetector is wire bonded to a corresponding input pad of the TIA array. A ground pad is disposed between adjacent input pads and connected to a ground plane via an isolated bonding strip on the photodetector array in order to alleviate crosstalk between the channels. The output data channels of the TIA are tightly spaced at the output pads of the TIA and are fanned out on the ceramic to increase the spacing of the data channels as they extend from the TIA. The ROSA includes the use of embedded capacitance to reduce crosstalk and noise by decoupling reference planes formed within the multilayer ceramic substrate. Input and output ground planes of the TIA are separated in the vicinity of the TIA and coupled on a ceramic layer spaced farther from the TIA, to alleviate crosstalk.

A nested transimpedance amplifier (TIA) circuit comprises a zero-order TIA having an input and an output. A first transconductance amplifier has an input that communicates with said output of said zero-order TIA and an output. A first feedback resistance has one end that communicates with said input of said zero-order TIA and an opposite end that communicates with said output of said first transconductance amplifier. A first feedback capacitance has a first end that communicates with said input of said zero-order TIA and a second end that communicates with said output of said zero-order TIA. A capacitance has one end that communicates with said input of said zero-order TIA.

An amplifier circuit for converting the current signal from an optical receiving element into a voltage signal. The amplifier circuit includes a transimpedance amplifier having a differential amplifier and a feedback resistor, a first adjustable resistor which is connected in parallel with the feedback resistor and whose resistance value is defined by a first control signal, and a series circuit connected in parallel with the feedback resistor. The series circuit includes a first capacitor and a second adjustable resistor, whose resistance value is defined by a second control signal. The two adjustable resistors are preferably formed as MOS resistors and have the same control signal applied to them. The amplifier circuit permits the provision of a high dynamic range during the operation of a transimpedance amplifier.