Abstract: Digital-to-analog converters (DACs) are used widely in electronics. The DACs are usually not ideal and typically exhibits errors, e.g., static mismatch errors. This disclosure describes a digital calibration technique for DAC static mismatch in continuous-time delta-sigma modulators (CTDSMs). The methodology utilizes the DAC unit elements (UEs) themselves to measure each other's mismatch. There are no extra circuitries except for the logic design inside DAC drivers or comparators. The methodology is an attractive calibration technique for high performance CTDSMs, especially for high speed system in multi-gigahertz range with low over-sampling rate (OSR).

Abstract: A transducer amplification circuit may include a preamplifier circuit with a signal input receiving a transducer signal to provide an amplified transducer signal comprising audible frequency components and ultrasonic frequency components. The transducer amplification circuit may include a first sigma-delta modulator configured to sample and quantize the amplified transducer signal to generate a first digital transducer signal comprising a first quantization noise signal. The first sigma-delta modulator may include a first noise transfer function having a high pass response in at least a portion of an audible frequency range to push the quantization noise signal to ultrasonic frequencies. A second sigma-delta modulator is configured to sample and quantize the amplified transducer signal to generate a second digital transducer signal comprising a second quantization noise signal.

Abstract: Apparatus and methods for autozero amplifiers are provided herein. In certain configurations, an autozero amplifier includes at least three transconductance stages and an autozero timing control circuit configured to control an autozero sequence of the transconductance stages. The autozero timing control circuit can stagger autozeroing of the transconductance stages, such that a relatively small amount of the amplifier's amplification circuitry is connected to or disconnected from the amplifier's signal path at any given time. For example, in certain configurations, when one of the transconductance stages in autozeroed over a particular time interval, the remaining transconductance stages can operate in parallel to provide amplification during that time interval.

Abstract: An embodiment of a digital-to-analog converter circuit includes a resistor network connected to an output node, a switch network having a first plurality of switches connecting the resistor network to a first circuit node and a second plurality of switches connecting the resistor network to a second circuit node, a voltage reference to supply a reference voltage to the first circuit node, and a current generator connected to the first circuit node and the second circuit node, to generate a compensation current, draw the compensation current from the first circuit node, and supply the compensation current to the second circuit node. The current generator can generate the compensation current as a function of a current or a voltage of a component of the voltage reference or as a function of an analog output voltage produced at the output node.

Abstract: This disclosure describes techniques and methodologies of using passive continuous time (CT) delay line for high-speed CT analog-to-digital converter (ADC) applications. In a continuous-time residual producing stage common to these CT ADCs, a proper delay between the analog input and DAC output is crucial. Specifically, using an inductor-capacitor (LC) lattice based delay element to enable high-performance CT pipeline ADC and CT delta-sigma (??) ADC. The use of an LC lattice based delay element provides wide-band group delay for continuous-time signals with well-controlled impedance. This will be an essential circuit component to build a high-performance CT ADCs especially in architectures where the generation of a low-noise and low-distortion residual between the CT signal and its digitized version is needed. LC lattice based delay element enables noise-free, distortion-free wideband delay that is required for high speed continuous-time pipeline ADC and delta-sigma ADC.

Abstract: In one example, there is disclosed herein a processor configured for interruptible atomic exclusive memory operations. For example, a load exclusive (LDEX) may be followed by a store exclusive (STREX), with the two together forming an atom. To facilitate timely handling of interrupts, the STREX operation is split into two parts. The STREX_INIT is not interruptible but has a determinate execution time because it takes a fixed number of clock cycles. The STREX_INIT sends the value out to the memory bus. It is followed by a STREX_SYNC operation that polls a flag for whether a return value is available. STREX_SYNC is interruptible, and methods are disclosed for determining whether, upon return from an interrupt, atomicity of the operation has been broken. If atomicity is broken, the instruction fails, while if atomicity is preserved, the instruction completes.

Abstract: A proportional to absolute temperature (PTAT) circuit is provided. By judiciously combining circuit elements into two or more cell it is possible to effectively dump bias current into impedance resistive element of a first cell from other cells of the circuit. As a result the circuit as a whole can operate with smaller resistive elements and therefore occupy less area when implemented in silicon. It is also possible to reduce the supply current that is required for providing specific output currents or voltages.

Abstract: A feedback cancellation assembly for an electroacoustic communication apparatus may include a signal transmission path for generation and emission of an outgoing sound signal to an external environment through an electrodynamic loudspeaker and a signal reception path comprising a microphone for generation of a microphone input signal corresponding to sound received from the external environment. The signal reception path may generate a digital microphone signal. The outgoing sound signal may be acoustically coupled to the microphone. An electronic feedback cancellation path may be coupled between a tapping node and a summing node to produce a feedback cancellation signal to the summing node.

Abstract: Example embodiments of this disclosure can provide an apparatus, a system, and a method of correcting for charge lost from a sampling capacitor as a result of an analog to digital conversion being performed. In an embodiment, there is provided a method of operating an analog to digital converter comprising at least a first sampling capacitor used to sample an input signal, where the method can further comprise a correction step of modifying the voltage across the at least first sampling capacitor, the correction step being performed prior to commencing an acquire phase.

Abstract: Various methods and systems are provided to control a probe moving towards fluid held in a container. The probe is moved towards the fluid to take a sample of the fluid in the container. To take a sample, probe is actuated to hit the fluid surface and to pass the fluid surface by a predetermined distance. Capacitive sensing which incorporates the probe itself is used to support an approach engine for controlling the motion of the probe. The approach engine determines the speed of the probe based on capacitance measurements, and in some cases based on position information of the probe. The approach engine ensures the probe hits the surface of the fluid in the container in order to take a sample while ensuring the probe does not hit the bottom of the container.

Abstract: A charge pump cell, comprising: an input node; an output node; Q channels, where Q is an integer greater than one, and where at least two of the channels comprise: a capacitor; a unidirectional current flow device; an output diode; and a channel drive signal node; and wherein a first current flow node of the unidirectional current flow device is connected to a first node of the capacitor at a channel node, a second node of the capacitor is connected to the channel drive signal node, a second current flow node of the unidirectional current flow device is connected to the input node, and the output diode is connected between the channel node and the output node

Abstract: This application discusses, among other things apparatus and methods for a voltage boost circuit. In an example, a voltage boost circuit can include first and second inverters, sharing a first supply node, and sharing a second supply node, a first charge transfer capacitor, configured to couple a first clock signal to the first inverter output, a second charge transfer capacitor, configured to couple a second clock signal to the second inverter output, the second clock signal being out-of-phase with the first clock signal, a first gate drive capacitor, configured to couple the first clock signal to the second inverter input, and a second gate drive capacitor, configured to couple the second clock signal to the first inverter input.

Abstract: Apparatus and methods for frequency lock enhancement of phase-locked loops (PLLs) are provided. In one aspect, a PLL can include a VCO and a calibration voltage generation circuit that can generate a calibration voltage for controlling a tuning voltage input of the VCO when the VCO is being coarsely tuned. Additionally, the calibration voltage generation circuit can sense a temperature of the PLL, and can control a voltage level of the calibration voltage to provide compensation based on the sensed temperature. The calibration voltage generation circuit can include a bandgap reference circuit configured to generate a zero-to-absolute-temperature (ZTAT) current and a proportional-to-absolute temperature (PTAT) current, and the calibration voltage can be generated based in part on a difference between the PTAT current and the ZTAT current.

Abstract: This disclosure relates to temperature stabilization of at least a portion of an amplifier, such as a logarithmic amplifier, and/or a band gap reference circuit. In one aspect, one or more stages of an amplifier, a heater, and a temperature sensor are included in a semiconductor material and surrounded by thermally insulating sidewalls.

Abstract: Apparatus and methods for frequency lock enhancement of phase-locked loops (PLLs) are provided. In one aspect, a PLL can include a VCO having a tuning voltage input and a frequency tuning circuit configured to set a frequency band setting of the VCO. The frequency tuning circuit can include a voltage monitor configured to compare the voltage level of the tuning voltage input to one or more tuning voltage threshold levels, a control circuit configured to control at least a frequency band setting and a bias current setting of the VCO, and an amplitude detection circuit configured to compare an amplitude of an oscillation signal of the VCO to one or more amplitude threshold levels.

Abstract: Circuits and method for providing voltage reference circuits that include low drift over time and lower operating voltages are provided. Generally, it is desirable that a reference circuit provide an accurate and precise reference over time. The voltage reference circuits described can provide for good long term stability, operation at lower voltages than prior designs, consistent output voltage with reduced variability due to process changes and mismatches, low noise in the reference voltage, and other advantages.

Abstract: A silicon substrate is provided that may facilitate the formation of RF components more cheaply by using a silicon layer formed by the Czochralski process, and having a carrier life time killing layer deposited on the silicon layer.

Abstract: In one aspect, an electrical signal converter is disclosed. The exemplary electrical signal converter may include a plurality of ordered converter elements. Element selection logic may be provided to pseudorandomly select a pointer to a switch matrix, wherein the switch matrix maps converter elements according to a stepwise “delta-two-maximum pattern.” Advantageously, pseudorandom stepwise delta-two-maximum patterns may be applied both to a first order converter, and to a feedback converter for error correction.

Abstract: An analog switch may be maintained reliably in an off state. The switch comprises: a P-type first transistor having a source, a drain and a gate, a N-type second transistor having a source, a drain and a gate, and a switch control circuit to drive the gates of the first and second transistors. The drain of the first transistor and the source of the second transistor are connected at a first node, and the source of the first transistor and the drain of the second transistor are connected at a second node. When the voltage at the first or second nodes falls outside of a supply voltage range of the switch control circuit, the switch control circuit is operable, in response to a signal to make the switch high impedance, by adjusting the gate voltages of the first transistor and the second transistor.

Abstract: A phase corrector for laser trimming a component, the phase corrector comprising: a first correction structure located to a first side of the component, the first correction structure comprising first and second correction regions at first and second distances from the component; and a second correction structure located to a second side the component, the second correction structure comprising third and fourth correction regions at third and fourth distances from the component.