A system (100) for providing a timing signal with tunable temperature dependency in an electronic device may include a timing circuit (102) and an initial setting circuit (104). The timing circuit (102) may include a delay stage (106) and a gate stage (108). The delay stage (106) may be configured to receive an input signal and to produce a delayed signal by introducing a delay to the input signal. The gate stage (108) may be configured to receive the delayed signal and a threshold setting signal, to produce an output signal using the delayed signal and a logic threshold, and to set an initial value of the logic threshold according to the threshold setting signal. The initial setting circuit (104) may be configured to allow the threshold setting signal to be tuned for providing the time delay with a specified temperature dependency.

A method is presented for characterizing a digital circuit for determining an optimum operating point of the digital circuit. The digital circuit includes sequential elements; conducting data paths; a clock tree; a time fault sensor receiving as input a data signal and configured to detect during a detection window a transition of the data signal; and a system for setting first and second operating parameters of the circuit. The method includes a) activating a conducting data path leading to the sequential element coupled to the sensor; b) determining, for a given value of the first parameter, a first value of the second parameter from which the sensor detects a transition of the data signal during the detection window, the values of the first and second parameters defining an operating point of the circuit; and c) correcting the operating point.

A method is presented for characterizing a digital circuit for determining an optimum operating point of the digital circuit. The digital circuit includes sequential elements; conducting data paths; a clock tree; a time fault sensor receiving as input a data signal and configured to detect during a detection window a transition of the data signal; and a system for setting first and second operating parameters of the circuit. The method includes a) activating a conducting data path leading to the sequential element coupled to the sensor; b) determining, for a given value of the first parameter, a first value of the second parameter from which the sensor detects a transition of the data signal during the detection window, the values of the first and second parameters defining an operating point of the circuit; and c) correcting the operating point.

A reference voltage buffer circuit includes an operational amplifier, a capacitor switching module, a first transistor and a second transistor. The operational amplifier includes two input terminals and an output terminal, where the two input terminals receive an input reference voltage and a feedback voltage, respectively. A gate electrode of the first transistor is coupled to the capacitor switching module, and a source electrode of the first transistor provides the feedback voltage. A gate electrode of the second transistor is coupled to the capacitor switching module, and a source electrode of the second transistor provides an output reference voltage. In addition, the operational amplifier generates a stable control voltage to the gate electrodes of the first transistor and the second transistors via the capacitor switching module while the output terminal of the operational amplifier is not directly connect to the gate electrodes of the first transistor and the second transistors.

A reference voltage buffer circuit includes an operational amplifier, a capacitor switching module, a first transistor and a second transistor. The operational amplifier includes two input terminals and an output terminal, where the two input terminals receive an input reference voltage and a feedback voltage, respectively. A gate electrode of the first transistor is coupled to the capacitor switching module, and a source electrode of the first transistor provides the feedback voltage. A gate electrode of the second transistor is coupled to the capacitor switching module, and a source electrode of the second transistor provides an output reference voltage. In addition, the operational amplifier generates a stable control voltage to the gate electrodes of the first transistor and the second transistors via the capacitor switching module while the output terminal of the operational amplifier is not directly connect to the gate electrodes of the first transistor and the second transistors.

A communication circuit includes a first buffer configured to output a signal indicative of a first logic state or a second logic state, a signal in which the first logic state and the second logic state are defined being input to the first buffer, a second buffer configured to output a signal indicative of any one of the first logic state, the second logic state, and a third logic state, the signal output from the first buffer being input to the second buffer, and a monitoring circuit configured to monitor a logic state indicated by the signal output from the first buffer and cause the second buffer, in a case where the logic state does not change during a first period, to output the signal indicative of the third logic state.

A communication circuit includes a first buffer configured to output a signal indicative of a first logic state or a second logic state, a signal in which the first logic state and the second logic state are defined being input to the first buffer, a second buffer configured to output a signal indicative of any one of the first logic state, the second logic state, and a third logic state, the signal output from the first buffer being input to the second buffer, and a monitoring circuit configured to monitor a logic state indicated by the signal output from the first buffer and cause the second buffer, in a case where the logic state does not change during a first period, to output the signal indicative of the third logic state.

A phase rotator calibration system is provided. The phase rotator calibration system includes a phase rotator portion having input for receiving an input signal and an output for providing an output signal. A calibration portion is coupled to the phase rotator portion. The calibration portion is configured to determine a phase error based on a phase estimation. The phase estimation is generated by way of an arccosine function.

Disclosed is a device for detecting the margin of a circuit operating at an operating speed. The device includes: a signal generating circuit generating an input signal including predetermined data; a first adjustable delay circuit delaying the input signal by a first delay amount and thereby generating a delayed input signal; a circuit under test performing a predetermined operation based on a predetermined operation timing and thereby generating a to-be-tested signal according to the delayed input signal; a second adjustable delay circuit delaying the to-be-tested signal by a second delay amount and thereby generating a delayed to-be-tested signal; a comparison circuit comparing the data included in the delayed to-be-tested signal with the predetermined data based on the predetermined operation timing and thereby generating a comparison result; and a calibration circuit determining whether the circuit under test passes a speed test according to the comparison result.

Disclosed is a device for detecting the margin of a circuit operating at an operating speed. The device includes: a signal generating circuit generating an input signal including predetermined data; a first adjustable delay circuit delaying the input signal by a first delay amount and thereby generating a delayed input signal; a circuit under test performing a predetermined operation based on a predetermined operation timing and thereby generating a to-be-tested signal according to the delayed input signal; a second adjustable delay circuit delaying the to-be-tested signal by a second delay amount and thereby generating a delayed to-be-tested signal; a comparison circuit comparing the data included in the delayed to-be-tested signal with the predetermined data based on the predetermined operation timing and thereby generating a comparison result; and a calibration circuit determining whether the circuit under test passes a speed test according to the comparison result.