Texas Instruments Corporation

Burr-brown Corporation

Texas Instruments Tucson Corporation

Joel Martin Halbert

Kenneth W Murray

Doug Weiser

Myron J Koen

Ahmad Dashtestani

Wolfgang Heinz Schwartz

Christoph Andreas Othmar Dirnecker

Karsten Jens Spinger

Joseph Anthony DeSantis

Alexei Sadovnikov

Mattias E Dahlstrom

Bharath Karthik Vasan

Paul G Damitio

Alan Varner

Tyler James Archer

Jimmy R Naylor

Thomas R Anderson

Vinay Agarwal

Xiyao Zhang

Dan Yuan

Wallace Burney

Michael A Steffes

A fully-differential amplifier (FDA) includes a core differential amplifier and a common-mode input voltage control circuit. The core differential amplifier includes differential inputs. The common-mode input voltage control circuit is coupled to the differential inputs. The common-mode input voltage control circuit is configured to generate an error signal as a difference of an input common mode voltage at the differential inputs and a target common mode input voltage (VICM); and to adjust the input common mode voltage to the VICM based on the error signal.

Fully-differential amplifier with input common-mode voltage control

Examples of amplifiers accurately generate control currents for control terminals of output drivers using current-replication transistors and current mirrors. An input terminal of a first current mirror is coupled to the control terminal of a first current-replication transistor, and an input terminal of a second current mirror is coupled to the control terminal of a second current-replication transistor. The output terminals of the first and second current mirrors are coupled to the control terminals of first and second output drivers, respectively. First and second intermediate currents indicative of first and second currents flowing to the first and second output driver elements, respectively, are generated. Using the first and second current mirrors, first and second control currents are generated to control the first and second output driver elements, respectively, by scaling the first and second intermediate currents according to the gain factors of the current mirrors.

Control of base currents for output driver transistors in amplifiers

Examples of amplifiers use current-replication transistors and a separation circuit coupled to such transistors to separate error current components from other current components in a pre-driver of an amplifier. In response to driving the current-replication transistors with the separated error current components, replica base current components that approximate error-modulation components of the pre-driver base currents are generated. Replica-current subtraction circuitry coupled to the current-replication transistors then subtract the replica base current components from the pre-driver base currents, affecting cancellation of the error-modulation components of the pre-driver base currents.

Control of input bias current modulation in amplifiers

In one example an electronic device includes a first resistor and a second resistor. The first resistor includes a first resistive layer located over a substrate, the first resistive layer having a first sheet resistance. The second resistor includes a first portion of a second resistive layer located over the substrate, the second resistive layer having a second sheet resistance different from the first sheet resistance. The first resistive layer is located between the substrate and a second noncontiguous portion of the second resistive layer.

Method and structure for dual sheet resistance trimmable thin film resistors

A method of forming an electronic device includes forming an opening through a dielectric layer located over a first resistive layer, the first resistive layer having a first sheet resistance. A second resistive layer is deposited over the dielectric layer and into the opening. The second resistive layer has a second sheet resistance different from the first sheet resistance. A portion of the second resistive layer is removed, thereby forming first and second noncontiguous portions of the second resistive layer, wherein the second portion of the second resistive layer contacts the first resistive layer.

A method of forming an electronic device includes forming first, second and third doped regions at a surface of a semiconductor substrate. A first buried layer is located within the semiconductor substrate below the first, second and third doped regions. Fourth and fifth doped regions are laterally spaced apart along the substrate and extend from the surface of the substrate to the first buried layer, the first, second and third doped regions being located between the fourth and fifth doped regions. A second buried layer is formed within the substrate and between the fourth and fifth doped regions such that a first portion of the semiconductor substrate is located between the first buried layer and the second buried layer, and a second portion of the semiconductor substrate is located between the first, second and third doped regions and the second buried layer.

Integrated JFET structure with implanted backgate

A semiconductor device contains a JFET with a channel layer having a first conductivity type in a substrate. The JFET has a back gate having a second, opposite, conductivity type below the channel. The back gate is laterally aligned with the channel layer. The semiconductor device is formed by forming a channel mask over the substrate of the semiconductor device which exposes an area for the channel dopants. The channel dopants are implanted into the substrate in the area exposed by the channel mask while the channel mask is in place. The back gate dopants are implanted into the substrate while the channel mask is in place, so that the implanted channel dopants are laterally aligned with the implanted channel dopants.

An integrated circuit includes a higher sheet resistance resistor and a lower sheet resistance resistor, disposed in a same level of dielectric layers of the integrated circuit. The higher sheet resistor has a body region and head regions in a higher sheet resistance layer. The lower sheet resistor has a body region and head regions in a lower sheet resistance layer, which is thicker than the higher sheet layer. The higher sheet resistor has an upper head layer contacting the higher sheet layer at each head region of the higher sheet layer. Each upper head layer has a same composition and thickness as the lower sheet layer of the lower sheet resistor. The lower sheet resistor is free of head layers over the lower sheet resistance layer.

Method and structure for dual sheet resistance trimmable thin film resistors at same level

A bus driver circuit (FIG.) is disclosed. The circuit includes a signal lead of a bus () and a reference terminal (Vss). A first transistor (MN) has a first control terminal and has a first current path coupled to the reference terminal. A second transistor (MN) has a second control terminal coupled to the first control terminal and has a second current path coupled between the signal lead and the reference terminal. A third transistor (MP) is arranged to provide a first current through the first current path when the signal lead is in a first logic state (high). A fourth transistor (MP) is arranged to apply a voltage to the second control terminal when the signal lead is in a second logic state (low).

Transition rate controlled bus driver circuit with reduced load sensitivity

A signal processing circuit includes a circuit stage for operating on signals in a signal path of an input signal, including main circuitry for operating on relatively small-value signals and alternative circuitry for amplifying/processing signals during a condition which otherwise would cause thermal imbalance in the main circuitry. The circuit stage includes switching circuitry for coupling signals in the signal path of the input signal to the main input circuitry during normal small-signal operating conditions and for coupling signals in the signal path of the input signal to the alternative circuitry during the condition which otherwise would cause thermal imbalance in the main circuitry.

Circuit and method for avoiding circuit performance degradation caused by time-variable thermal imbalances

An amplifier includes a differential amplifier () having an input stage () for amplifying a differential input signal (Vin), and an output stage () coupled to the input stage () for producing and output signal (Vout). The input stage () includes main input circuitry (A) for amplifying small-signal values of the input signal (Vin) and alternative input circuitry (B) for amplifying the input signal (Vin) during conditions which cause thermal imbalance in the main input circuitry (B). The input stage () includes switching circuitry () for coupling the input signal (Vin) to the main input circuitry (A) during normal small-signal operating conditions and to the alternative input circuitry (A) during large-signal operating conditions that cause thermal imbalance in the main input circuitry (B).

Differential amplifier circuit and method for reducing thermally induced offsets caused by large differential signals

A system and method for implementing an amplifier capable of limiting or clamping an amplifier output signal is described. A clamp buffer and an input buffer cooperate to bias an output circuit according to the relative level of a clamp signal and an input signal. In a normal mode, in which the input signal has a first relationship with the clamp signal, the output circuit provides an output signal based on the input signal. In a clamping mode, in which the input signal has a second relationship with the clamp signal, the output circuit provides an output signal based on the clamp signal, which can be substantially fixed. The clamp signal can be set by the user to establish a desired clamping range.

Output stage, amplifier and associated method for limiting an amplifier output

A low power current feedback amplifier having a lower output impedance input stage is provided. To reduce the output impedance, an input stage comprises a closed-loop input buffer. An exemplary input buffer comprises a closed-loop current feedback amplifier configured within the overall current feedback amplifier, wherein the output of the input buffer corresponds to the inverting node of the overall current feedback amplifier. The closed-loop configuration of the input buffer is facilitated by the use of an internal feedback resistor coupled from an inverting input terminal of the input buffer to the output of the input buffer, which corresponds to the inverting input terminal of the overall current feedback amplifier. The closed-loop input buffer realizes a low output impedance since the loop gain reduces the output impedance of the input buffer. With a lower output impedance, the bandwidth of the current feedback amplifier becomes more independent of the gain, even at low current implementations.

Low power current feedback amplifier

An output stage amplifier circuit in accordance with the present invention overcomes many shortcomings of the prior art. A output stage amplifier circuit for providing a high output voltage and current reference signal suitably includes an output buffer configured with a compensation circuit for reducing disturbances introduced into the output stage amplifier circuit by voltage supply rails, such as parasitic ringing and other disturbances. The compensation circuit can suitably comprise a first compensation device, such as at least one capacitor, and a second compensation device, such as at least one capacitor. The compensation devices are suitably coupled between an input terminal of the output stage amplifier circuit and a pair of transistors proximate a pair of output transistors of the output stage amplifier circuit, and are configured to provide &ldquo;pole-zero&rdquo; compensation to the output stage amplifier circuit.

Output stage amplifier with compensation circuitry

A circuit for multiplexing a selected one of a plurality of input signals to an output conductor includes a plurality of diamond follower input buffers each having an input terminal coupled to receive an input signal, respectively. A diamond follower output buffer has an output coupled to the output conductor. A feedback resistor is coupled between the output conductor and the outputs of the input buffers. A first current mirror has a control input coupled to a first current bias terminal of each input buffer, and a second current error has a control input coupled to a second current bias terminal of each input buffer. The first and second current mirrors have outputs connected to drive the input of the output buffer and bias current terminals of the output buffer to provide a high slew rate.

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Tucson, AZ, United States of America

Joel Martin Halbert