Abstract: An amplifier system includes a first amplifier stage having an input and an output. A second amplifier stage has an input and an output, the input of the second amplifier stage being connected to the output of the first amplifier stage. A transistor has a control terminal, a first terminal, and a second terminal, the first terminal of the transistor being coupled to the output of the first amplifier stage and the input of the second amplifier stage. A first capacitance has a first terminal and a second terminal, the first terminal of the first capacitance being connected to the input of the first amplifier stage, the second terminal of the first capacitance being connected to the second terminal of the transistor. A first current source to source current to amplifier system, the first current source being is connected to the output of the first amplifier stage. A second current source will sink current from the amplifier system.

Abstract: A differential transimpedance amplifier circuit comprises a first amplifier, a second amplifier and a first resistance having one end that communicates with the input of the first amplifier. A second resistance has one end that communicates with the second amplifier. A fourth amplifier has an input that communicates with the output of a third amplifier. Third and fourth resistances communicate with the input and output of the third and fourth amplifiers, respectively. Fifth and sixths amplifiers have an input that communicates with the output of the second and fifth amplifiers, respectively. Seventh and eighth amplifiers have an input that communicates with the output of the fourth, seventh amplifier. An opposite end of the first resistance communicates with the output of the eighth amplifier, and an opposite end of the third resistance communicates with the output of the sixth amplifier.

Abstract: An amplifier circuit comprises an amplifier circuit input and a first amplifier having an input that communicates with the amplifier circuit input and an output. A second amplifier has an input that communicates with the output of the first amplifier and an output. A first resistance has one end that communicates with the input of the first amplifier. An inverter that has an input that communicates with the output of the second amplifier and an output that communicates with an opposite end of the first resistance.

Abstract: A transimpedance amplifier circuit comprises a first amplifier having an input, an output and a first transconductance. A second amplifier has an input that communicates with the output of the first amplifier, an output and a second transconductance. A first resistance has one end that communicates with the input of the first amplifier. A third amplifier has an input that communicates with the output of the second amplifier, an output and a third transconductance. A fourth amplifier has an input that communicates with the output of the third amplifier, an output and a fourth transconductance. An inverter has an input that communicates with the output of the fourth amplifier and an output that communicates with an opposite end of the first resistance.

Abstract: A differential transimpedance amplifier (TIA) circuit comprises first, second, third, fourth, fifth and sixth transconductance amplifiers having an input, an output and first, second, third, fourth, fifth and sixth transconductance gains, respectively. A first resistance communicates with said third transconductance amplifier and with said second transconductance amplifier. A second resistance communicates with said third transconductance amplifier and said third transconductance amplifier. A third resistance communicates with said sixth transconductance amplifier and said fifth transconductance amplifier. A fourth resistance communicates with said sixth transconductance amplifier and with said sixth transconductance amplifier. A fifth resistance communicates with said third transconductance amplifier and said fourth transconductance amplifier. A sixth resistance communicates with said sixth transconductance amplifier and said first transconductance amplifier.

Abstract: An amplifier system includes a first amplifier, a second amplifier, a first capacitance, and a first transistor. The first amplifier has an input and an output. The second amplifier has an input that communicates with the output of the first amplifier. The first capacitance has one end that communicates with the input of the first amplifier. The first transistor has a control terminal, a first terminal that communicates with the output of the first amplifier, and a second terminal that communicates with another end of the first capacitance.

Abstract: A write driver circuit for a magnetic storage medium includes a first write driver sub-circuit that has an output that communicates with a first node of a write head. The first write driver circuit includes a first driver circuit and a first feedback path between the input and the output of the first driver circuit. A second write driver sub-circuit has an output that communicates with a second node of the write head. The second write driver sub-circuit includes a second driver circuit and a second feedback path between the input and the output of the second driver circuit. The write driver circuit has a substantially constant output impedance during operation, balanced differential and common mode resistances, and a substantially constant common mode voltage across the write head during operation.

Abstract: A write driver system comprises first switching devices that generate gate drive signals. A write driver circuit includes second switching devices that are controlled by the gate drive signals. The second switching devices have higher voltage stress thresholds than the first switching devices and wherein the second switching devices have slower switching times than the first switching devices.

Abstract: An amplifier circuit comprises a first capacitance having one end that communicates with an input of a first amplifier stage. An amplifier has a first gain, an input that communicates with an opposite end of the first capacitance, and an output. A second capacitance has a first end that communicates with the output of the amplifier and an opposite end that communicates with an input of a second amplifier stage. A broadband buffer has an input that communicates with the output of the amplifier and an output that communicates with the one end of the second capacitance.

Abstract: Aspects provide for the broadband amplification of RF signals. Other aspects provide for the conversion of single ended input to differential output. Various aspects provide for tuning the response to a particular frequency band. Other aspects provide for various transconductance elements. In several aspects, broadband current to voltage converters and voltage to current converters are presented. Some implementations incorporate a buffer circuit, and various implementations incorporate feedback circuits.

Abstract: An amplifier circuit comprises a first amplifier having an input and an output. A second amplifier has an input that communicates with an output of the first amplifier. A third amplifier has an input that communicates with an input of the first amplifier. A fourth amplifier has an input that communicates with an output of the third amplifier and an output that communicates with the input of the second amplifier. A switched capacitance circuit selectively couples a capacitance to at least one of the input of the third amplifier and the output of third amplifier.

Abstract: An amplifier circuit includes first, second, third and fourth transconductance amplifiers that each have an input, an output and a transconductance gain. The outputs of the first, second and third amplifiers communicate with the inputs of the second, third and fourth amplifiers, respectively. A first resistance has ends that communicate with the input and the output of the second amplifier, respectively. A second resistance has ends that communicate with the input and the output of the fourth amplifier, respectively. Fifth, sixth, seventh and eighth amplifiers each have an input, an output and a gain. The outputs of the fifth, sixth and seventh amplifiers communicate with the inputs of the sixth, seventh and eighth amplifiers, respectively. A third resistance has one end that communicates with the input of the first amplifier and an opposite end that communicates with the output of the eighth amplifier.

Abstract: A write driver circuit for a magnetic storage medium that communicates with a write head having first and second nodes comprises a first driver circuit having a first input, a first output that communicates with the first node, and a first feedback path between the first input and the first output. A second driver circuit has a second input, a second output that communicates with the second node, and a second feedback path between the second input and the second output. A first write current circuit selectively drives current through the write head in a first direction. A second write current circuit selectively drives current through the write head in a second direction. A first boost circuit decreases a first transition period between current flowing in the first direction and current flowing in the second direction.

Abstract: A write driver circuit for a magnetic storage medium that communicates with a write head having first and second nodes comprises a first driver circuit with an input and an output that communicates with the first node of the write head. A first charge pump communicates with said input and said output of said first driver circuit and provides additional current to said input of said first driver circuit during a first transition period between current flowing through the write head in a first direction and current flowing through the write head in a second direction. A second driver circuit with an input and an output communicates with the second node of the write head. A second charge pump communicates with said input and said output of said second driver circuit and provides additional current to said input of said second driver circuit during a second transition period between current flowing through the write head in said second direction and current flowing through the write head in said first direction.

Abstract: A transimpedance amplifier circuit includes a first amplifier with an input, an output and a first transconductance. A second amplifier has an input that communicates with the output of the first amplifier, an output and a second transconductance. A first resistance has one end that communicates with the input of the first amplifier. An inverter has an input that communicates with the output of the second amplifier and an output that communicates with an opposite end of the first resistance. A second resistance has one end that communicates with the input of the second amplifier and an opposite end that communicates with the output of the second amplifier. A third resistance has one end that is connected to the output of the second amplifier. A first capacitance has one end that communicates with the one end of the first resistance and an opposite end that communicates with the opposite end of the first resistance.

Abstract: A transimpedance amplifier (TIA) circuit comprises a first operational transconductance amplifier (OTA) having an input and an output. A second OTA has an input and an output. A third OTA has an input that communicates with the output of the first OTA and an output that communicates with the input of the second OTA. A first feedback path communicates with the input and the output of the first OTA and that includes a first resistor. A second feedback path communicates with the input and the output of the second OTA and that includes a first resistance. A third feedback path communicates with the input of the first OTA and the output of the second OTA.

Abstract: An amplifier circuit comprises a first amplifier having an input and an output. A second amplifier has an input that communicates with an output of the first amplifier. A third amplifier has an input that communicates with an input of the first amplifier. A fourth amplifier has an input that communicates with an output of the third amplifier and an output that communicates with the input of the second amplifier. A switched capacitance circuit selectively couples a capacitance to at least one of the input of the third amplifier and the output of third amplifier.

Abstract: An amplifier system includes a first amplifier, a second amplifier, a first capacitance, and a first transistor. The first amplifier has an input and an output. The second amplifier has an input that communicates with the output of the first amplifier. The first capacitance has one end that communicates with the input of the first amplifier. The first transistor has a control terminal, a first terminal that communicates with the output of the first amplifier, and a second terminal that communicates with another end of the first capacitance.

Abstract: An amplifier circuit comprises a first operational transconductance amplifier (OTA) has an input that communicates with the output of the first amplifier. A third amplifier has an input that communicates with the input of the first amplifier and an output. A fourth OTA has an input that communicates with the output of the third amplifier and an output. A feedback resistance communicates with the input and the output of the fourth OTA. A capacitance communicates with the output of the fourth OTA and with the input of the second OTA.

Abstract: An amplifier circuit comprises a first operational transconductance amplifier (OTA) has an input that communicates with the output of the first amplifier. A third amplifier has an input that communicates with the input of the first amplifier and an output. A fourth OTA has an input that communicates with the output of the third amplifier and an output. A feedback resistance communicates with the input and the output of the fourth OTA. A capacitance communicates with the output of the fourth OTA and with the input of the second OTA.