Analog Devices,inc.

Analog Devices International Unlimited Company

Analog Devices Global Unlimited Company

Gary Carreau

Michael C Coln

Yoshinori Kusuda

Bruce E Amazeen

Michael C W Coln

Patrick Stanley Riehl

Christopher Peter Hurrell

Brian Jeffrey Wengreen

Alain Valentin Guery

Baozhen Chen

Sean Patrick Kowalik

Mark D Maddox

Gustavo Castro

Camille L Huin

Simon Nicholas Fiedler Basilico

Camille Louis Huin

Michael Christian Wohnsen Coln

Scott Andrew Hunt

Cathal Murphy

Kenneth M Feen

Richard J Capistran

Systems and methods described herein relate to fingerprint-on-display recognition. In particular, the systems and methods described herein may recognize a fingerprint when a finger of a user is placed on a display and authenticate the user based on the recognized fingerprint. Further, the embodiments described herein may utilize multiple colors and/or secondary factors to reduce erroneous authentications of the user. The approaches may improve the accuracy of fingerprint authentication by using the multiple colors and/or secondary factors.

Fingerprint-on-display recognition

Amplifier systems for measuring a wide range of current are provided herein. In certain embodiments, an amplifier system includes a controllable sensing circuit, a first amplifier including an output configured to drive a device under test (DUT) through the controllable sensing circuit, and a second amplifier including an input coupled to the controllable sensing circuit and operable to generate a measurement signal indicating an amount of measured current of the DUT. The amplifier system further includes a control circuit operable to control a configuration or mode of the controllable sensing circuit suitable for a particular type of DUT.

Amplifier systems for measuring a wide range of current

Systems and methods are provided for an automatic exposure detection feature for adding to an x-ray panel readout device, including an imaging panel having a low power mode, a sense circuit for receiving an input signal in the low power mode and restricting an input signal voltage to a first voltage, and a sensor for sensing a change in the input signal voltage, wherein the change in input signal voltage indicates exposure to an x-ray signal.

Automatic exposure detection circuit for imaging applications

When reservoir capacitors are moved on-chip for individual bit decisions, a successive approximation register analog-to-digital converter (SAR ADC) has an addition source of error which can significantly affect the performance of the SAR ADC. Calibration techniques can be applied to measure and correct for such error in an SAR ADC using decide-and-set switching. Specifically, a calibration technique can expose the effective bit weight of each bit under test using a plurality of special input voltages and storing a calibration word for each bit under test to correct for the error. Such a calibration technique can lessen the need to store a calibration word for each possible output word to correct the additional source of error. Furthermore, another calibration technique can expose the effective bit weight of each bit under test without having to generate the plurality of special input voltages.

Calibration techniques for SAR ADCs with on-chip reservoir capacitors

The system may include a pixel array, a selector, a sampler, and a converter. The pixel array may generate output signals representing radiation incident upon the pixel array. The selector may select one of the output signals. The sampler may sample the selected output signal. The converter may generate a digital signal based upon the selected output signal. The sampler may include a charge integrator that compensates for parasitic capacitance of the selector by selecting a first feedback capacitance to obtain a first sample, and after obtaining the first sample, selecting a second feedback capacitance to obtain a second sample. The first feedback capacitance may be greater than the second feedback capacitance.

Gain-ranging charge amplifier

Apparatus and methods reduce common-mode error. An integrated circuit includes a plurality of signal channels, a first proxy channel, and a subtraction block. The signal channels are configured to receive a plurality of input signals and to generate a plurality of output signals, and each of the signal channels has a substantially similar circuit topology. The first proxy channel has a substantially similar circuit topology as the plurality of signal channels, and includes an output that can vary in relation to a common-mode error of the signal channels. The subtraction block is configured to generate a plurality of modified output signals by using the output of the first proxy channel to reduce the common-mode error of the plurality of output signal channels.

Apparatus and methods for reducing common-mode noise in an imaging system

Disclosed embodiments are directed to an electrical overstress protection circuit. The electrical overstress protection circuit may include an intermediate node receiving a reference voltage, a first pair of clamp devices, having opposite polarity, clamping an input signal line to the intermediate node, and a second pair of clamp devices, each clamping the intermediate node to one of two reference potentials. The electrical overstress protection circuit may also include a filter connected to the intermediate node to reduce noise at the intermediate node.

Guarded electrical overstress protection circuit

A circuit system for performing correlated double sampling may include a signal sampling stage having an amplifier with a feedback capacitor and a pair of storage capacitors coupled to an output of the amplifier, and a differential analog to digital converter (ADC) having a pair of inputs coupled respectively to storage capacitors of the signal sampling stage. The signal sampling stage may receive reset and signal values from a sensor device and may store processed versions of those signals on respective storage capacitors. The differential ADC may generate a digital value representing a signal captured by the sensor device from a differential digitization operation performed on the processed versions of the reset and signal values. In this manner, the system may correct for any signal errors introduced by components of the sampling stage.

Correlated double-sample differencing within an ADC

Techniques to reduce correlated errors in a multi-channel sampling system. A plurality of clock signals may be generated from a master clock signal, each with edges offset from each other. The offset clock signals may be distributed to a plurality of sampling devices. Each sampling device may capture a respective input signal according to its offset clock. In this manner, the sampling units may sample their inputs signals over a distributed window of time rather than sampling in response to a common clock edge. By distributing the switching operations performed by the sampling units, noise effects are likely to be reduced.

Techniques for reducing correlated errors in multi-channel sampling systems

An amplifier system can include a feedback amplifier circuit having an amplifier, a feedback capacitor connected between an input terminal and an output terminal of the amplifier by at least one first switch, and a reset capacitor connected across the feedback capacitor by at least one second switch and between a pair of reference voltages by at least one third switch. During an input-signal processing phase of operation, a control circuit may close the at least one first switch and open the at least one second switch to electrically connect the feedback capacitor between the input and output terminals to engage feedback processing by the feedback amplifier circuit, and close the third switch to electrically connect the reset capacitor between the first and second voltages to charge the reset capacitor to a selectable voltage difference. During a reset phase of operation, the control circuit may open the at least one third switch, close the at least one second switch and open the at least one first switch to electrically connect the reset capacitor across the feedback capacitor to reset the feedback capacitor using the reset capacitor. The amplifier system can optionally include a plurality of the feedback amplifier circuits.

Reset and resettable circuits

An integrated circuit may include a plurality of circuit sub-systems that include at least one converter circuit operating in respective critical phases and non-critical phases of operation, a clock distribution circuit that has an input for an externally-supplied clock signal that is active during the non-critical phases and inactive during the critical phases, and a clock generator to generate an internal clock signal to the converter circuit that is active when the external-supplied clock signal is inactive.

Opportunistic timing control in mixed-signal system-on-chip designs

A system for converting an analog signal to a digital codeword having N bit positions that includes a dual DAC structure having a small DAC and a large DAC. At least one comparator is coupled to the small DAC and large DAC. The small DAC performs bit trials to calculate bit positions 1 to M, and the large DAC with performs bit trial calculates bit positions M+1 to N after having been set with bit decisions from the bit trials of the small DAC.

Dual DAC structure for charge redistributed ADC

An analog-to-digital conversion system includes an analog-to-digital converter (ADC), a plurality of receivers, each for capturing input analog signals, a multiplexer having inputs coupled to each of the receivers and an output coupled to the ADC, the multiplexer establishing a signal path between a selected one of the inputs and the output in response to an index signal, and a mux controller to supply a random sequence of index signals to the multiplexer.

System and method for reducing pattern noise in analog system processing

A system for randomizing aperture delay in a time interleaved ADC system that includes a plurality of selection switch stages corresponding to each of the ADCs in the system and a second selection switch stage coupled to a voltage source. A plurality of conductors extend between the second selection switch stage and each of the selection switch stages, in excess of the number of ADCs in the system. For each of N ADCs in the system, the selection switch stages and the second selection switch stage support at least N+1 selectable conductive paths extending from each of the sampling capacitors of the ADCs to the voltage source. Random selection of the N+1 paths can randomize aperture delay.

Method to reduce error in time interleaved analog-to-digital converters arising due to aperture delay mismatch

An SAR analog-to-digital converter performs bit decisions in each of a plurality of clock cycles. A sense circuit monitors signals input to a latch within a comparator of the ADC and, when the signals are sufficient to establish a bit decision, the sense circuit terminates a currently active clock cycle causes a bit decision to occur in advance of a normal expiration of the clock cycle. If the signals are insufficient to establish a bit decision prior to a default expiration time of the clock cycle, the clock cycle concludes at the default expiration time.

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Plaistow, NH, United States of America

Gary Carreau