Analog Devices,inc.

Padraig Cooney

Moshe Gerstenhaber

Colin Gerard Lyden

Techniques to develop negative impedance circuits that may operate to their power supply rails. The techniques may include generating currents in response to voltage signals presented at respective input terminals of a negative impedance circuit. The voltage signals may be differential signals. The generated currents may be driven through a common impedance within the negative impedance circuit. The currents flowing through the common impedance may be mirrored back to the input terminals of the negative impedance circuit. The negative impedance circuit may be controlled to operate about a common-mode voltage for the circuit.

Techniques for developing a negative impedance

Aspects of the present invention provide apparatuses and methods to provide slew rate enhancement during an initial stage of operation of an amplifier and processing of an input signal with low noise introduction during a subsequent amplification stage of operation. During the initial stage, a high bandwidth component of the amplifier can be engaged to provide slew rate enhancement of the overall amplifier. The adaptive slew rate enhancement can be based on a detected imbalance of an output of a low bandwidth component of the amplifier. Once a desired operating state of the amplifier is achieved, the high bandwidth component can be disengaged. The low bandwidth component can then solely operate on a received input signal during the amplification stage. The low bandwidth component can be low power and can introduce low levels of noise, thereby ensuring minimal noise introduction and corruption of the amplified output signal of the amplifier.

Fast settling low power low noise amplifier

A method and system that may include a pair of amplifier transistors and an output coupled to a load device. The precharge buffer may be controlled by an activation signal. The precharge buffer may also include a pair of level shifters. Each level shifter may be provided in association with a respective one of the transistors, and each may provide a respective level shift to an input signal at a common signal source based on a reference voltage. Outputs of the level shifters may be coupled to the respective transistors. The precharge buffer may also include a bypass signal path extending from the common signal source to the load device. A signal path may be controlled by another activation signal, and the precharge buffer and the bypass signal may be enabled during mutually exclusive states of the activation signal.

Open loop rail-to-rail precharge buffer

A high performance follower device coupled with a slew enhancement circuit includes an amplifier circuit containing a follower device connected to a three-terminal device, whereupon current drawn through the three-terminal device is amplified through a current amplifier and sent to the source terminal of the follower device to stabilize the output voltage when the input signal is changed rapidly or if the output voltage is disturbed by a changing output load. The presence of a cascode device also allows for the bootstrapping of the follower device.

High precision follower device with zero power, zero noise slew enhancement circuit

An electric discharge device includes a bipolar transistor configuration comprising a base, an emitter, and a collector. At least one pinched resistor is formed in a region comprising both the base and emitter so as to produce a pinched resistive area that develops a voltage once the bipolar transistor experiences junction breakdown.

Robust ESD cell

A circuit for removing non-linearity produced when an amplifier includes a load that results in non-linear current levels is provided. The circuit includes a first transistor element being coupled to one of the differential inputs associated with the amplifier. A second transistor element is coupled to another of the differential inputs associated with the amplifier. The second transistor element is coupled to the current associated with the load. Current passing the collectors of the first and second transistors elements are arranged to be always equal so as to eliminate in the circuit the changes between the base currents of the second transistor element and first transistor element caused by the current associated with the load.

Circuit to prevent load-induced DC nonlinearity in an op-amp

An amplifier system includes an instrumentation amplifier arrangement being designed to amplify the difference between two voltage inputs with a defined gain, and to produce a single-ended output referenced to a known reference point. A front end circuit is coupled to the instrumentation amplifier. The front end circuit is configured to include a current clamp to actively limit the current in a gain resistor of the instrumentation amplifier to prevent input currents flowing when the instrumentation amplifier is over-driven.

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Somerville, MA, United States of America

Padraig Cooney