Texas Instruments Corporation

Paul G Damitio

Joel Martin Halbert

Sergey V Alenin

Bharath Karthik Vasan

Alan Varner

Ahmad Dashtestani

Tyler James Archer

Xavier P Ramus

He Qing

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

Amplifier circuitry () includes a driver amplifier () and an integrator amplifier (A) producing an output signal (V) that controls a pass transistor (Q) coupled to a pump capacitor (C). Input circuitry () controls the direction of ramping of the output signal during a first interval to boost a supply voltage (V) of the driver amplifier via the pump capacitor, and also controls the direction of ramping to recharge the pump capacitor following a second interval. In one embodiment, pump capacitor recharging circuitry (Q,R,I) completes the recharging of the pump capacitor following the second interval after it has been partially recharged by the integrator amplifier.

Gated class H amplifier/line driver system and method

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

Circuitry for increasing the maximum output current magnitude of a diamond buffer (Q) having increased maximum output current provides a bias current of a first magnitude (I) into an emitter of a PNP first input transistor (Q) and sinks a bias current of the first magnitude out of an emitter of an NPN second input transistor (Q). The decrease is sensed in a collector current of the first input transistor caused by a demand for increased base current by a NPN first output transistor (Q) of the diamond buffer. A collector current (Ic()) in an NPN another transistor (Q) is increased in response to the decrease in the collector current of the first input transistor. The increased collector current in the first transistor is mirrored into a base of the first output transistor to boost its base current and maintain operation of the first input transistor when the amount of base current demanded by the first output transistor exceeds the first magnitude.

Low quiescent current output stage and method with improved output drive

A high output current wideband output stage/buffer amplifier that has reduced quiescent current requirements. The output stage/buffer amplifier includes a diamond follower circuit having a pair of complementary output load-driving bipolar junction transistors (BJTs), a pair of pre-driver BJTs, and a plurality of current boost BJTs. As the base current of one of the driver transistors starts to increase in response to an increasing load current, the current through a corresponding pre-driver transistor decreases, thereby increasing the collector current of a corresponding boost transistor. The increased collector current of the boost transistor is fed back to a current mirror, causing a concomitant increase in the base current of the driver transistor.

High output current wideband output stage/buffer amplifier

Systems and methods to improve bias matching (e.g., for a current feedback amplifier) are described. A compensation signal is combined with one or more bias signals to mitigate mismatch between the bias signals. The compensation signal is generated to correspond to the mismatch between the bias signals. This approach can be implemented to improve performance of an associated amplifier, such as by reducing offset at an input of a portion of the amplifier (e.g., an input buffer) that is biased by the bias signals.

System and method for improved bias matching

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

Paul G Damitio