Embodiments of the invention provide for integrated circuits for testing one or more transistors for process variation effects. According to an embodiment, the integrated circuit can include: a plurality of ring oscillator macro circuits, wherein each ring oscillator macro circuit includes two ring oscillators, a first multiplexer, and a first divide-by-two circuit; a multiplexer stage; a divide-by-two circuit stage; a second multiplexer; a second divide-by-two circuit; and frequency measurement circuit. According to another embodiment, the integrated circuit can include: a first shift register including a plurality of devices-under-test; a second shift register including a plurality of static latches; a first multiplexer configured to receive outputs from each of the plurality of DUTs; a second multiplexer configured to receive outputs from each of the plurality of static latches; and a comparator configured to compare an output from the first multiplexer with an output from the second multiplexer.

In accordance with at least one aspect of this disclosure, a controller for an aircraft electrical system includes, a software safe module. In embodiments, the software safe module can be configured to determine whether there was a sudden power failure upon controller initialization, and cause operation of the controller in a software safe mode if there was a sudden power failure such that manual intervention is required to leave the software safe mode to prevent repetitive power failure of the controller.

A circuit screening system including a target circuit under test receiving a first testing signal in a first period and a second testing signal in a second period; a power circuit providing a supply voltage to the target circuit under test, the supply voltage maintaining at a first voltage level in the first period and deviating from the first voltage level, and maintaining at the first voltage level in the second period; and a clock generating circuit providing a clock signal to the target circuit under test, the clock signal triggering the target circuit under test to receive the first testing signal in the first period and the second testing signal in the second period; the clock signal having a first profile and a second profile in the first period and the second period, respectively, and the first profile and the second profile having a phase difference.

A test system is disclosed. The test system includes a tester, a first voltage stabilization circuit, and a device under test (DUT). The tester generates a first operational voltage and a control signal. The first voltage stabilization circuit transmits a second operational voltage, associated with the first operational voltage, to a socket board. The DUT operates with the second operational voltage received through the socket board. The first voltage stabilization circuit is further configured to control, according to the control signal, the second operational voltage to have a first voltage level when the DUT is operating.

A monitoring circuit includes a sensor circuit having a plurality of devices and a selection circuit, which selects a device to be monitored among the plurality of devices, an input circuit, which applies, based on input digital data, a first signal to the device to be monitored and an output circuit, which generates output digital data based on a second signal generated by the sensor circuit. The input circuit includes a digital-to-analog converter, and the output circuit includes an analog-to-digital converter.

Detection circuitry for an integrated circuit (IC) includes voltage divider circuitry, comparison circuitry, and calibration circuitry. The voltage divider circuitry receives a power supply signal and output a first reference voltage signal and a supply voltage signal based on the power supply signal. The comparison circuitry compares the first reference voltage signal and the supply voltage signal to generate an output signal. The calibration circuitry alters one or more parameters of the voltage divider circuitry to increase a voltage value of the supply voltage signal based on the comparison of the first reference voltage signal with the supply voltage signal.

An IC includes a plurality of pads at a top surface of a semiconductor wafer, an amplifier configured to receive a first AC signal at an input terminal, and output a second AC signal at an output terminal, a first detection circuit coupled to the input terminal and configured to output a first DC voltage to a first pad of the plurality of pads responsive to the first AC signal, and a second detection circuit coupled to the output terminal and configured to output a second DC voltage to a second pad of the plurality of pads responsive to the second AC signal.

A method for detecting error on an input/output (IO) pin of an integrated circuit includes using the input/output pin of the integrated circuit in a first mode by receiving or sending a first value as analog data or digital data. The input/output pin is toggled in a test mode after each instance of using the input/output pin in the first mode. The test mode includes providing a second value disparate from the first value during a set time after using the input/output pin in the first mode, receiving back during the set time a resulting value based on providing the second value, measuring the resulting value, and identifying an error on the input/output pin of the integrated circuit based on the measured resulting value.

A temperature measurement circuit includes a band-gap reference circuit configured to generate a band-gap reference voltage that is fixed regardless of an operation temperature, a reference voltage generator circuit configured to generate a measurement reference voltage by adjusting the band-gap reference voltage, a sensing circuit configured to generate a temperature-variant voltage based on a bias current, where the temperature-variant voltage is varied depending on the operation temperature, an analog-digital converter circuit configured to generate a first digital code indicating the operation temperature based on the measurement reference voltage and the temperature-variant voltage, and an analog built-in self-test (BIST) circuit configured to generate a plurality of flag signals indicating whether each of the band-gap reference voltage, the measurement reference voltage, and a bias voltage corresponding to the bias current is included in a predetermined range.

In accordance with at least one aspect of this disclosure, a controller for an aircraft electrical system includes, a software safe module. In embodiments, the software safe module can be configured to determine whether there was a sudden power failure upon controller initialization, and cause operation of the controller in a software safe mode if there was a sudden power failure such that manual intervention is required to leave the software safe mode to prevent repetitive power failure of the controller.