Texas Instruments Corporation

Ahmad Dashtestani

Joel Martin Halbert

Alan Varner

Paul G Damitio

Michael A Steffes

An amplifier driver circuit () includes first (-) and second (-) feedback amplifiers including first (-) and second (-) upper current mirrors, respectively, and first (-) and second (-) lower current mirrors, respectively, first (-) and second (-) amplifier input stages receiving a common mode input signal, and first (-) and second (-) amplifier output stages coupled to outputs of the first and second amplifier input stages, respectively. Each current mirror has an input (IN) and first (OUT) and second (OUT) outputs. Upper bias terminals of the first (-) and second (-) amplifier input stages are coupled to the inputs (IN) of the first (-) and second (-) upper current mirrors, respectively, and are cross-coupled to the second outputs (OUT) of the second (-) and first (-) lower current mirrors, respectively. Lower bias terminals of the first (-) and second (-) amplifier input stages are coupled to the inputs (IN) of the first (-) and second (-) lower current mirrors, respectively, and are cross-coupled to the second outputs (OUT) of the second (-) and first (-) upper current mirrors, respectively, to oppose signals at the inputs (IN) of the current mirrors in response to the common mode input signal.

Common-mode bandwidth reduction circuit and method for differential applications

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.

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Tucson, AZ, United States of America

Ahmad Dashtestani