Abstract: A digital-to-analog converter circuit that creates an analog waveform from an input digital waveform. Operating the circuit comprises using the input digital waveform to 1) operate a charge control switch to set a charge time period, 2) operate a discharge control switch to set a discharge time period, 3) set a charge current magnitude using a charge gain, and 4) set a discharge current magnitude using a discharge gain. A charge source electrically charges a load capacitor during the charge time period (i.e., the charge mode). A discharge source electrically discharges the load capacitor during the discharge time period (i.e., the discharge mode). A circuit output transmits the analog waveform defined by the charge mode and the discharge mode. A charge current magnitude greater than the discharge current magnitude produces an upward-sloping analog waveform. A charge current magnitude less than the discharge current magnitude produces a downward-sloping analog waveform.

Abstract: An analog filter is presented that comprises a chain of filter stages, a feedback resistor for providing a negative feedback, and a feedback capacitor for providing a positive feedback. Each filter stage has an input node and an output node. The output node of a filter stage is connected to the input node of an immediately succeeding filter stage through a resistor. The feedback resistor has a first end connected to the output node of the last filter stage along the chain of filter stages, and a second end connected to the input node of a first preceding filter stage. The feedback capacitor has a first end connected to the output node of one of the chain of filter stages, and a second end connected to the input node of a second preceding filter stage.

Abstract: An analog filter is presented that comprises a chain of filter stages, a feedback resistor for providing a negative feedback, and a feedback capacitor for providing a positive feedback. Each filter stage has an input node and an output node. The output node of a filter stage is connected to the input node of an immediately succeeding filter stage through a resistor. The feedback resistor has a first end connected to the output node of the last filter stage along the chain of filter stages, and a second end connected to the input node of a first preceding filter stage. The feedback capacitor has a first end connected to the output node of one of the chain of filter stages, and a second end connected to the input node of a second preceding filter stage.

Abstract: A passive mixer includes a transconductance amplifier having a source degeneration capacitance. The transconductance amplifier has an input for receiving an input signal and an output for outputting a current signal. A multiplier is provided for mixing a local oscillator signal with the current signal so as to provide an output signal at an output of the passive mixer. A capacitive load is connected to the output of the passive mixer.

Abstract: The invention provides a system for providing tunable balanced loss compensation in an electronic filter. Tunable balanced loss compensation is provided by using cross-connected balanced transconductors and self-connected balanced transconductors. The cross-connected balanced transconductors and the self-connected transconductors compensate the unbalanced loss across the electronic filter. The self-connected balanced transconductors compensate the balanced loss across the electronic filter. Further, the cross-connected and the self-connected balanced transconductors are tunable by adjusting the values of their transconductances, thereby providing tunable balanced loss compensation.

Abstract: A passive mixer includes a transconductance amplifier having a source degeneration capacitance. The transconductance amplifier has an input for receiving an input signal and an output for outputting a current signal. A multiplier is provided for mixing a local oscillator signal with the current signal so as to provide an output signal at an output of the passive mixer. A capacitive load is connected to the output of the passive mixer.

Abstract: The invention provides a system for providing tunable balanced loss compensation in an electronic filter. Tunable balanced loss compensation is provided by using cross-connected balanced transconductors and self-connected balanced transconductors. The cross-connected balanced transconductors and the self-connected transconductors compensate the unbalanced loss across the electronic filter. The self-connected balanced transconductors compensate the balanced loss across the electronic filter. Further, the cross-connected and the self-connected balanced transconductors are tunable by adjusting the values of their transconductances, thereby providing tunable balanced loss compensation.

Abstract: In one embodiment, an amplifier circuit has at least one branch and current-source circuitry providing a tail current to the branch, which has at least one load tank, at least one input transistor coupled to the load tank, and variable-impedance circuitry coupled between an input node of the amplifier circuit and the gate of the input transistor. The transconductance of the input transistor can be altered to achieve two or more different gain settings for the amplifier circuit. The variable-impedance circuitry can be controlled to contribute any one of at least two different levels of impedance to the overall input impedance of the amplifier circuit. If the transconductance of the input transistor is reduced, then the variable-impedance circuitry can increase the level of impedance contributed to the overall input impedance of the amplifier circuit such that the overall input impedance of the amplifier circuit remains substantially unchanged.

Abstract: In one embodiment, an amplifier circuit has at least one branch and current-source circuitry providing a tail current to the branch, which has at least one load tank, at least one input transistor coupled to the load tank, and variable-impedance circuitry coupled between an input node of the amplifier circuit and the gate of the input transistor. The transconductance of the input transistor can be altered to achieve two or more different gain settings for the amplifier circuit. The variable-impedance circuitry can be controlled to contribute any one of at least two different levels of impedance to the overall input impedance of the amplifier circuit. If the transconductance of the input transistor is reduced, then the variable-impedance circuitry can increase the level of impedance contributed to the overall input impedance of the amplifier circuit such that the overall input impedance of the amplifier circuit remains substantially unchanged.