Abstract: A current mirror circuit includes a first transistor connected to a voltage source, a gate of the first transistor being connected to a drain of the first transistor, a current source connected to the drain and the gate of the first transistor, the current source being configured to generate a predetermined first output current, a sample and hold circuit having an input connected to the gate of the first transistor, a second transistor connected to the voltage source, a gate of the second transistor being connected to an output of the sample and hold circuit, and a controller operatively connected to the sample and hold circuit, the controller being configured to operate the sample and hold circuit at a predetermined sampling frequency to attenuate bias noise from the first transistor in a second output current from the second transistor.

Abstract: A phase lock loop circuit includes a phase detector, loop filter, voltage controlled oscillator, and a divider. The divider includes a controller and a memory that stores a lookup table of signal levels for a sinusoidal feedback signal. The divider receives an output signal from the voltage controlled oscillator and generates an output signal corresponding to the values in the lookup table in a predetermined order to generate a sinusoidal feedback signal. The divider generates a new output for each cycle of the output signal from the voltage controlled oscillator and enables PLL bandwidth that meets or exceeds a frequency of the reference signal.

Abstract: A gyroscopic sensor includes a vibratory gyroscopic sensor element, first and second drive electrodes positioned proximate to the vibratory gyroscopic sensor element, and a drive circuit operatively connected to the first and second drive electrodes. The drive circuit is configured to generate a stepped sinusoidal waveform having a plurality of steps, each step having a predetermined duration and each step having an output level in a plurality of predetermined output levels for the stepped sinusoidal waveform including at least three positive output levels and at least three negative output levels to generate oscillation of the vibratory gyroscopic sensor element at a predetermined frequency.

Abstract: A feedback circuit provides a feedback signal to a transducer. The feedback circuit includes an ADC that generates digital representations of a feedback signal, digital controller that identifies adjustments for the feedback, and DAC that generates an analog output of the adjusted feedback signal. The digital controller performs speculative computation to identify adjustments for the feedback signal output for each output value from the ADC prior to receiving the output from the ADC. The ADC and DAC include sigma-delta modulators that operate with a zero clock cycle delay in a forward path. The ADC, digital controller, and DAC generate adjustments to the feedback output signal with reduced delay that reduce phase lag and improve phase margin to maintain stability in the transducer.

Abstract: A digital phase lock loop circuit includes a phase detector, loop filter, finite impulse response filter (FIR), a plurality of digital to analog converters (DACs), a voltage controlled oscillator (VCO), and a divider. The FIR filter includes a predetermined number of taps, where each tap is connected to an input of one DAC in the plurality of DACs. The FIR filter attenuates high-frequency quantization error in a digital control signal that the plurality of DACs converts to an analog control signal for the VCO. The FIR filtered control signal reduces or eliminates quantization noise higher-frequency components that would otherwise be generated as DC quantization noise in a feedback signal generated by the divider.

Abstract: A current mirror circuit includes a first transistor connected to a voltage source, a gate of the first transistor being connected to a drain of the first transistor, a current source connected to the drain and the gate of the first transistor, the current source being configured to generate a predetermined first output current, a sample and hold circuit having an input connected to the gate of the first transistor, a second transistor connected to the voltage source, a gate of the second transistor being connected to an output of the sample and hold circuit, and a controller operatively connected to the sample and hold circuit, the controller being configured to operate the sample and hold circuit at a predetermined sampling frequency to attenuate bias noise from the first transistor in a second output current from the second transistor.

Abstract: A feedback circuit provides a feedback signal to a transducer. The feedback circuit includes an ADC that generates digital representations of a feedback signal, digital controller that identifies adjustments for the feedback, and DAC that generates an analog output of the adjusted feedback signal. The digital controller performs speculative computation to identify adjustments for the feedback signal output for each output value from the ADC prior to receiving the output from the ADC. The ADC and DAC include sigma-delta modulators that operate with a zero clock cycle delay in a forward path. The ADC, digital controller, and DAC generate adjustments to the feedback output signal with reduced delay that reduce phase lag and improve phase margin to maintain stability in the transducer.

Abstract: A phase lock loop circuit includes a phase detector, loop filter, voltage controlled oscillator, and a divider. The divider includes a controller and a memory that stores a lookup table of signal levels for a sinusoidal feedback signal. The divider receives an output signal from the voltage controlled oscillator and generates an output signal corresponding to the values in the lookup table in a predetermined order to generate a sinusoidal feedback signal. The divider generates a new output for each cycle of the output signal from the voltage controlled oscillator and enables PLL bandwidth that meets or exceeds a frequency of the reference signal.

Abstract: A digital phase lock loop circuit includes a phase detector, loop filter, finite impulse response filter (FIR), a plurality of digital to analog converters (DACs), a voltage controlled oscillator (VCO), and a divider. The FIR filter includes a predetermined number of taps, where each tap is connected to an input of one DAC in the plurality of DACs. The FIR filter attenuates high-frequency quantization error in a digital control signal that the plurality of DACs converts to an analog control signal for the VCO. The FIR filtered control signal reduces or eliminates quantization noise higher-frequency components that would otherwise be generated as DC quantization noise in a feedback signal generated by the divider.

Abstract: A gyroscopic sensor includes a vibratory gyroscopic sensor element, first and second drive electrodes positioned proximate to the vibratory gyroscopic sensor element, and a drive circuit operatively connected to the first and second drive electrodes. The drive circuit is configured to generate a stepped sinusoidal waveform having a plurality of steps, each step having a predetermined duration and each step having an output level in a plurality of predetermined output levels for the stepped sinusoidal waveform including at least three positive output levels and at least three negative output levels to generate oscillation of the vibratory gyroscopic sensor element at a predetermined frequency.

Abstract: A method of detecting a signal in radio frequency identification (RFID) transponder (FIG. 1) is disclosed. The method includes receiving a signal (FIG. 7) having a first time in a first logic state (high) and having a second time in a second logic state (low). A weight (700, 702) is determined in response to the first time and the second time. An output signal (from A2D) is produced in response to the weight and one of the first and second logic states.

Abstract: A method of detecting a signal in radio frequency identification (RFID) transponder (FIG. 1) is disclosed. The method includes receiving a signal (FIG. 7) having a first time in a first logic state (high) and having a second time in a second logic state (low). A weight (700, 702) is determined in response to the first time and the second time. An output signal (from A2D) is produced in response to the weight and one of the first and second logic states.

Abstract: An embodiment of the invention provides a single-ended polar transmitting circuit. The single-ended polar transmitting circuit comprises a DAC, a differential-to-single-ended converter, a GmC filter and a load. The GmC filter comprises two gain stages, two filters, two switching devices, a translinear loop and a current mirror. When a second clock signal is high, a first current is conducted through the load, a second switching device and a second gain stage. When a first clock signal is high, a second current is conducted through a first switching device and the second gain stage. The first gain stage has a transconductance Gm1 and the second gain stage has a transconductance Gm2. The bandwidth of the GmC filter is approximately equal to the square root of the quantity (Gm1*Gm2)/(C1*C2). The bandwidth of the GmC filter is substantially a constant value.

Abstract: An embodiment of the invention provides a single-ended polar transmitting circuit. The single-ended polar transmitting circuit comprises a DAC, a differential-to-single-ended converter, a GmC filter and a load. The GmC filter comprises two gain stages, two filters, two switching devices, a translinear loop and a current mirror. When a second clock signal is high, a first current is conducted through the load, a second switching device and a second gain stage. When a first clock signal is high, a second current is conducted through a first switching device and the second gain stage. The first gain stage has a transconductance Gm1 and the second gain stage has a transconductance Gm2. The bandwidth of the GmC filter is approximately equal to the square root of the quantity (Gm1*Gm2)/(C1*C2). The bandwidth of the GmC filter is substantially a constant value.

Abstract: In accordance with at least some embodiments, an electronic device comprises a digital-to-analog converter (DAC) having a DAC element array. Reference-rotated data weighted averaging (RRDWA) is applied to the DAC element array.

Abstract: In accordance with at least some embodiments, an electronic device comprises a digital-to-analog converter (DAC) having a DAC element array. Reference-rotated data weighted averaging (RRDWA) is applied to the DAC element array.

Abstract: An active-passive continuous-time analog-to-digital converter and a method of continuous-time sigma-delta analog-to-digital conversion. In certain embodiments, the converter has a reduced power consumption, and the method requires less power to carry out. One embodiment of the converter has a signal input and includes: (1) an input summing junction coupled to the signal input, (2) a folded cascode transconductor having an input coupled to the input summing junction and (3) a feedforward path that couples the signal input to at least two nodes within the folded cascode transconductor.

Abstract: Various systems and methods for low power identification are described herein. For example, a radio frequency device including a radio frequency energy receiver. The radio frequency energy receiver is operable to receive a radio frequency energy and to convert the radio frequency energy to a DC current. In addition, the device further includes a first clock generator that generates a first clock at a first frequency and second clock generator that generates another clock based on the first clock. The first clock generator includes a duty cycle correction circuit. The second clock has a positive going clock edge for each edge of the first clock.

Abstract: A voltage regulation circuit for an RFID circuit having a voltage limiter circuit including a current sensing element for sensing current through the voltage limiter circuit. The voltage limiter generates a limited voltage. A voltage regulator is coupled to the limited voltage for generating a regulated output voltage. The voltage regulator has a dynamic biasing current responsive to an output of the sensing element for increasing bandwidth of the voltage regulator when current in the voltage limiter circuit increases.