An integrated circuit can include one or more clock controllers. Each clock controller corresponds to a different clock signal of a set of one or more clock signals of the integrated circuit. Each clock controller is configured to implement a clock stretch mode that generates a modified clock signal having a frequency that is less than the clock signal. The integrated circuit can include a trigger circuit configured to enable selected ones of the one or more clock controllers to implement the clock stretch mode. The trigger circuit and the one or more clock controllers are hardwired and are programmable using control infrastructure circuitry of the integrated circuit.

Methods, systems, and devices for signal sampling with offset calibration are described. For example, sampling circuitry may include an input pair of transistors where input signals may be provided to gate nodes of the transistors, and an output signal may be generated based on a comparison of voltages of drain nodes of the transistors. In some examples, source nodes of the transistors may be coupled with each other, such as via a resistance, and each source node may be configured to be coupled with a ground node. In some examples, a conductive path between the source nodes may be coupled with one or more switching components configurable for further coupling of the source nodes with the ground node. In some examples, enabling such switching components may add an electrical characteristic (e.g., capacitance) to the conductive path between the source nodes, which may be configurable to mitigate sampling circuitry imbalances.

A comparator includes: a first stage circuit, configured to receive a voltage signal to be compared and a reference voltage signal Vref, and to generate and output a first amplifying signal and a second amplifying signal based on the voltage signal to be compared and the reference voltage signal Vref; a second stage circuit, connected with the first stage circuit, configured to generate and latch a first output signal and a second output signal based on the first amplifying signal and the second amplifying signal; wherein the first stage circuit and/or the second stage circuit include(s) a first pair of cross-coupled transistors.

An apparatus includes a comparator. The comparator includes first and second pregain stages, and a switch network coupled to the first and second pregain stages. A plurality of switches in the switch network are operable to provide a feedback path around at least one of the first and second pregain stages. The comparator further includes a latch coupled to the second pregain stage.

A method for startup of a crystal oscillator (XO) with aid of external clock injection, associated XO and a monitoring circuit therein are provided. The XO includes an XO core circuit, an external oscillator, and an injection switch, where a quality factor of the external oscillator is lower than a quality factor of the XO core circuit. The method includes: utilizing the external oscillator to generate an injected signal; turning on the injection switch to make energy of the injected signal be injected into the XO core circuit, where an amplitude modulation (AM) signal is generated according to combination of the injected signal and an intrinsic oscillation signal from the XO core circuit; and controlling the external oscillator to selectively change an injection frequency of the injected signal according to the AM signal. More particularly, the injection switch is not turned off until the startup process is completed.

The present invention provides a lead-on detection circuitry of a biopotential acquisition system. The lead-on detection circuitry includes an input terminal, a duty-cycle controller, a transmitting signal generator and a mixer-based receiver. The duty-cycle controller is configured to generate a first clock signal. The transmitting signal generator is configured to generate a transmitting signal to the input terminal according to the first clock signal. The mixer-based receiver is configured to perform a mixing operation based on the first clock signal and the transmitting signal to generate an output signal, wherein the output signal indicates if an electrode of the biopotential acquisition system is in contact with a human body, and the electrode is coupled to the input terminal.

An integrated circuit can include latched comparator circuitry. The latched comparator circuitry may include first and second input transistors configured to receive an input signal, first and second cross-coupled inverting circuits, reset transistors, and a current pulse generator. The first and second inverting circuits may each include a pull-up transistor and a pull-down transistor. The first input transistor may be coupled between the pull-up and pull-down transistors in the first inverting circuit. The second input transistor may be coupled between the pull-up and pull-down transistors in the second inverting circuit. The reset transistors may be coupled in parallel with the pull-up transistors and may receive a clock signal. The current pulse generator may receive the clock signal and generate current pulse signals in response to detecting edges in the clock signal. Latched comparator circuitry configured and operated in this way can provide reduced clock kickback noise.

An analog to digital converter (ADC) comprising: a delay circuit having a complementary signal output; a first comparator having an input coupled to the complementary signal output of the delay circuit, the first comparator having a first output and a second output; a first dummy comparator having a first dummy input coupled to the first output and a second dummy input coupled to the second output, the first dummy comparator having a dummy output; a first interpolation comparator having an interpolation output and a first interpolation input coupled to the first output; a second dummy comparator having an input coupled to the interpolation output; and a second interpolation comparator having a second interpolation input and a third interpolation input, the second interpolation input coupled to the interpolation output and the third interpolation input coupled to the dummy output.

Provided is an image sensor including: a pixel section configured to include a plurality of pixels arranged therein; and an AD conversion unit configured to perform analog-to-digital (AD) conversion on a pixel signal on the basis of a result of comparison between a first voltage of a signal, which is obtained by adding, via capacitances, the pixel signal of the pixel and a reference signal that linearly changes in a direction opposite to the pixel signal, with a second voltage serving as a reference.

A comparator circuit includes a differential input circuit, a load circuit, a first current source, a first bias voltage supplying circuit, a third connection circuit, and a fourth connection circuit. The differential input circuit includes a first transistor to which a first input signal is supplied and a second transistor to which a second input signal is supplied. The load circuit includes a third transistor connected to the first transistor through a first connection circuit and a fourth transistor connected to the second transistor through a second connection circuit, gates of the third and fourth transistors being connected to the first connection circuit through a third capacitor. The first bias voltage supplying circuit supplies a first bias voltage to the gates of the third and fourth transistors and the third capacitor.