Abstract: A transimpedance amplifier (TIA) can include an operational amplifier with a programmable compensation capacitor, such as can be used for compensating first transconductance stage of an operational amplifier circuit that can be used in a TIA configuration. This technique is particularly suitable, for example, for an Optical Time Domain Reflectometer (OTDR) application, which can use variable pulsewidth launch pulses. Based on the pulsewidth of such launch pulses, the bandwidth of an operational amplifier of the TIA can be adjusted, such as to decrease the signal and noise bandwidth when relatively wider pulses are to be used, to improve the noise performance for such wider pulses, and to increase the signal and noise bandwidth when relatively narrower pulses are to be used.

Abstract: A transimpedance amplifier (TIA) can include an operational amplifier with a programmable compensation capacitor, such as can be used for compensating first transconductance stage of an operational amplifier circuit that can be used in a TIA configuration. This technique is particularly suitable, for example, for an Optical Time Domain Reflectometer (OTDR) application, which can use variable pulsewidth launch pulses. Based on the pulsewidth of such launch pulses, the bandwidth of an operational amplifier of the TIA can be adjusted, such as to decrease the signal and noise bandwidth when relatively wider pulses are to be used, to improve the noise performance for such wider pulses, and to increase the signal and noise bandwidth when relatively narrower pulses are to be used.

Abstract: An amplifier system with digital adaptive power boost includes a charge pump for providing a power supply to an amplifier. The charge pump may switch between a fixed input DC voltage and a boosted value for a certain period of time in response to an increase in an input signal to the amplifier. The charge pump may use a switching transistor which is switched on only when the input signal to the amplifier exceeds a threshold. The amplifier system may be used for envelope tracking, especially for envelope tracking of low duty cycle signals, e.g., xDSL or vDSL.

Abstract: An amplifier system with digital adaptive power boost includes a charge pump for providing a power supply to an amplifier. The charge pump may switch between a fixed input DC voltage and a boosted value for a certain period of time in response to an increase in an input signal to the amplifier. The charge pump may use a switching transistor which is switched on only when the input signal to the amplifier exceeds a threshold. The amplifier system may be used for envelope tracking, especially for envelope tracking of low duty cycle signals, e.g., xDSL or vDSL.