The embodiments herein describe technologies for back-gate biasing of clock trees using a reference generator. A circuit includes a set of clock buffers and a programmable voltage reference generator to apply a voltage to a back gate of a transistor of the set of clock buffers.

In an embodiment, a voltage comparator includes: a first switch having a conduction terminal coupled to an internal node that is coupled to an output of the voltage comparator; a current source; a capacitor; and a second switch connected in parallel with the capacitor, wherein the current source, the capacitor, and the first switch are coupled in series.

A repeater for open-drain bus communication and a system including the same is provided. The repeater includes at least one repeating unit having an A-side terminal connected to an A-side open-drain bus, and a B-side terminal electrically connected to a B-side open-drain bus. The repeater has a first mode to receive a signal at the A-side and to produce a signal at the B-side. The repeating unit includes a B-side accelerator element connected to the B-side terminal. The repeating unit when in a first mode includes a first control unit to, control the B-side accelerator element to pull up a voltage at the B-side when the voltage at the A-side surpasses a first threshold voltage during a rising edge of the voltage, and to subsequently control the B-side accelerator element to stop pulling up the voltage at the B-side when the voltage at the B-side surpasses a second threshold voltage.

Provided is a driver circuit that controls an output unit that switches whether or not to supply a current to an output line, in accordance with a potential difference between a first control signal to be input and a voltage of the output line. The driver circuit comprises a control line that transmits the first control signal to the output unit; a low potential line to which a predetermined reference potential is applied; a first connection switching unit that switches whether or not to connect the control line and the low potential line, in accordance with a second control signal; and a cutoff unit that is provided in series with the first connection switching unit between the control line and the low potential line and cuts off the control line and the low potential line based on a potential of the low potential line.

Systems and methods related to low power cryo-CMOS circuits with non-volatile threshold voltage offset compensation are provided. A system includes a plurality of devices configured to operate in a cryogenic environment, where a first distribution of a threshold voltage associated with the plurality of devices has a first value indicative of a measure of spread of the threshold voltage. The system further includes control logic, coupled to each of the plurality of devices, configured to modify a threshold voltage associated with each of the plurality of devices such that the first distribution is changed to a second distribution having a second value of the measure of spread of the threshold voltage representing a lower variation among threshold voltages of the plurality of devices.

In certain aspects, a receiving circuit includes a splitter, a first receiver, a second receiver, and a boost circuit. The splitter is configured to receive an input signal, split the input signal into a first signal and a second signal, output the first signal to the first receiver, and output the second signal to the second receiver. In certain aspects, the voltage swing of the input signal is split between the first signal and the second signal. The boost circuit may be configured to shift a supply voltage of the second receiver to boost a gate-overdrive voltage of a transistor in the second receiver during a transition of the input signal (e.g., transition from low to high). In certain aspects, the boost circuit controls the gate-overdrive voltage boosting based on the first signal and the second signal.

A switching driver circuit may have an output stage having an output switch connected between a switching voltage node and an output node. A switch network may control a switching voltage at the switching voltage node so that in one mode the switching voltage node is coupled to a positive voltage and in another mode the switching voltage node is coupled to ground voltage via a first switching path of the switch network. The circuit may also include an n-well switching block operable to, when the first switching voltage node is coupled to a positive voltage, connect the n-well of the first output switch to the switching voltage node, and, when the first switching voltage node is coupled to the ground voltage, connect the n-well of the first output switch to a first ground which is separate to the first switching voltage node and independent of the first switching path.

A voltage generating circuit includes a first transistor and a second transistor. Voltage of a substrate of the first transistor varies with a first parameter. The first parameter is any one of a supply voltage, an operating temperature, as well as a manufacturing process of the voltage generating circuit. A gate of the first transistor is connected to a drain of the first transistor. The substrate of the first transistor serves as an output of the voltage generating circuit. A gate of the second transistor is connected to a drain of the second transistor.

A CMOS output circuit includes a first P-MOSFET having a source connected to a power supply terminal, a drain connected to an output terminal, and a back gate connected to a first potential terminal; a first N-MOSEFET having a drain connected to the output terminal, a source connected to the ground terminal, and a back gate connected to a second potential terminal; a first potential switching portion arranged to switch whether to connect the first potential terminal to the power supply terminal or to the output terminal; a second potential switching portion arranged to switch whether to connect the second potential terminal to the ground terminal or to the output terminal; a first gate switching portion arranged to switch whether or not to short-circuit the gate of the first P-MOSFET to the first potential terminal; a second gate switching portion arranged to switch whether or not to short-circuit the gate of the first N-MOSFET to the second potential terminal; a first driver arranged to drive the gate of the first P-MOSFET in accordance with a first input signal; a second driver arranged to drive the gate of the first N-MOSFET in accordance with a second input signal; and a control portion arranged to control individual portions of the circuit when turning off both the first P-MOSFET and the first N-MOSFET, so as to connect the first potential terminal to one of the power supply terminal and the output terminal, which has a higher potential, to connect the second potential terminal to one of the ground terminal and the output terminal, which has a lower potential, to short-circuit the gate of the first P-MOSFET to the first potential terminal, and to short-circuit the gate of the first N-MOSFET to the second potential terminal.

A digital buffer device with self-calibration includes a first buffer circuit, detection circuit, and calibration circuit. The first buffer circuit has a buffer input terminal for receiving an input signal and a buffer output terminal as output of the digital buffer device. The detection circuit includes at least one second buffer circuit for receiving at least one reference signal and generating at least one detection signal to indicate circuit characteristic variations of the at least one second buffer circuit. The at least one second buffer circuit is of a same type of buffer as the first buffer circuit. The calibration circuit has a calibration input terminal for receiving the input signal, and a calibration output terminal coupled to the buffer output terminal. The calibration circuit is for calibrating the first buffer circuit to generate an output signal according to the input signal and the at least one detection signal.