A circuit for digital filtering an analog signal converted to digital, including an analog circuit to generate an analog signal, the analog signal including phase and/or gain errors. An analog-to-digital converter (ADC) to convert the analog signal to a digital signal output to a digital signal path. A frequency-dependent corrector filter included in the digital signal path, and configured as a parameterized filter, the parameterized filter configurable based on the DSA control signal with at least one complex filter parameter for each DSA attenuation step, to correct frequency-dependent errors in phase and/or gain.

A voltage regulator circuit having an internally compensated effective series resistance includes a control circuit to generate an out current at a regulated output voltage based on a reference voltage. The control circuit includes an amplifier, a resistive element to feedback output voltage to an input of the amplifier, and a compensation circuit to couple the internally compensated effective series resistance into the control circuit. The compensation circuit includes a first current sense device to generate a first sensed current proportional to a current through an N-type pass device, a second current sense device arranged to generate a second sensed current proportional to the current through the N-type pass device, and a bias circuit coupled to sink the first sensed current and the second sensed current to reduce a bias voltage across the resistive element below a threshold voltage.

Methods and apparatus for filtering a signal using a current-mode filter circuit implementing source degeneration. An example filter circuit generally includes an input node; an output node; a power supply node; a first transistor comprising a drain coupled to the input node; a second transistor comprising a drain coupled to the output node and comprising a gate coupled to a gate of the first transistor; a capacitive element coupled between the drain of the first transistor and the power supply node; a first resistive element coupled between the drain and the gate of the first transistor; a first source degeneration element coupled between a source of the first transistor and the power supply node; and a second source degeneration element coupled between a source of the second transistor and the power supply node.

We disclose transconductor-capacitor classical dynamical systems that emulate quantum dynamical systems and quantum-inspired systems by composing them with 1) a real capacitor, whose value exactly emulates the value of the quantum constant termed a Planck capacitor; 2) a quantum admittance element, which has no classical equivalent, but which can be emulated by approximately 18 transistors of a coupled transconductor system; 3) an emulated quantum transadmittance element that can couple emulated quantum admittances to each other; and 4) an emulated quantum transadmittance mixer element that can couple quantum admittances to each other under the control of an input. We describe how these parts may be composed together to emulate arbitrary two-state and discrete-state quantum or quantum-inspired systems including stochastics, state preparation, probability computations, state amplification, state attenuation, control, dynamics, and loss compensation.

We disclose transconductor-capacitor classical dynamical systems that emulate quantum dynamical systems and quantum-inspired systems by composing them with 1) capacitors that represent termed Planck capacitors; 2) a quantum admittance element, which can be emulated efficiently via coupled transconductors; 3) an emulated quantum transadmittance element that can couple emulated quantum admittances to each other; and 4) an emulated quantum transadmittance mixer element that can couple emulated quantum admittances to each other under the control of an input. We describe a Quantum Cochlea, a biologically-inspired quantum traveling-wave system with coupled emulated quantum two-state systems for efficient spectrum analysis that uses all of these parts. We show how emulated quantum transdmittance mixers can help represent an exponential number of quantum superposition states in the spectral domain with linear classical resources, even if they are not all simultaneously accessible as in actual quantum systems, and how the quantum cochlea is a very efficient spectrum analyzer for non-destructive readout of these spectral-domain signals.

A calibration method and a tuning method for an on-chip differential active RC filter are provided. The calibration method comprises: obtaining zero-crossing time of a differential signal outputted by a single-pole point real number filter by analyzing the single-pole point real number filter; setting a reference clock period according to the relationship between the zero-crossing time and the bandwidth of the single-pole point real number filter, and setting a calibration working time sequence according to the reference clock period; and scanning an RC configuration of an RC array according to the calibration working time sequence to realize calibration of the RC array.

We disclose transconductor-capacitor classical dynamical systems that emulate quantum dynamical systems and quantum-inspired systems by composing them with 1) capacitors that represent termed Planck capacitors; 2) a quantum admittance element, which can be emulated efficiently via coupled transconductors; 3) an emulated quantum transadmittance element that can couple emulated quantum admittances to each other; and 4) an emulated quantum transadmittance mixer element that can couple emulated quantum admittances to each other under the control of an input. We describe a Quantum Cochlea, a biologically-inspired quantum traveling-wave system with coupled emulated quantum two-state systems for efficient spectrum analysis that uses all of these parts. We show how emulated quantum transdmittance mixers can help represent an exponential number of quantum superposition states in the spectral domain with linear classical resources, even if they are not all simultaneously accessible as in actual quantum systems, and how the quantum cochlea is a very efficient spectrum analyzer for non-destructive readout of these spectral-domain signals.

We disclose transconductor-capacitor classical dynamical systems that emulate quantum dynamical systems and quantum-inspired systems by composing them with 1) capacitors that represent termed Planck capacitors; 2) a quantum admittance element, which can be emulated efficiently via coupled transconductors; 3) an emulated quantum transadmittance element that can couple emulated quantum admittances to each other; and 4) an emulated quantum transadmittance mixer element that can couple emulated quantum admittances to each other under the control of an input. We describe a Quantum Cochlea, a biologically-inspired quantum traveling-wave system with coupled emulated quantum two-state systems for efficient spectrum analysis that uses all of these parts. We show how emulated quantum transdmittance mixers can help represent an exponential number of quantum superposition states in the spectral domain with linear classical resources, even if they are not all simultaneously accessible as in actual quantum systems.

A circuit for digital filtering an analog signal converted to digital, including an analog circuit to generate an analog signal, the analog signal including phase and/or gain errors. An analog-to-digital converter (ADC) to convert the analog signal to a digital signal output to a digital signal path. A frequency-dependent corrector filter included in the digital signal path, and configured as a parameterized filter, the parameterized filter configurable based on the DSA control signal with at least one complex filter parameter for each DSA attenuation step, to correct frequency-dependent errors in phase and/or gain.

The cut-off frequency of an electronic filter having a nominal transfer function and a nominal cut-off frequency is estimated by: applying a first signal at a first frequency to an input of the filter while sampling an output of the filter in order to obtain a first magnitude measurement, the first frequency being less than the nominal cut-off frequency; applying a second signal at a second frequency to the input of the filter while sampling the output of the filter in order to obtain a second magnitude measurement, the second frequency being greater than the nominal cut-off frequency; and estimating the cut-off frequency of the filter based on the nominal transfer function, the first magnitude measurement, and the second magnitude measurement.