Disclosed herein are related to systems and methods for providing different power supply levels. In one aspect, a first circuit generates a first signal having a first amplitude according to a first supply voltage. A latch may be coupled to a resistor of a plurality of resistors coupled in series. One end of the resistor may be configured to provide to the latch a second supply voltage higher than the first supply voltage according to a third supply voltage higher than the second supply voltage, and another end of the resistor may be configured to receive the third supply voltage. The latch may modify the first signal to provide a second signal, according to the second supply voltage. An amplifier may amplify the second signal to provide a third signal having a second amplitude larger than the first amplitude, according to the third supply voltage.

Disclosed herein are related to systems and methods for providing different power supply levels. In one aspect, a first circuit generates a first signal having a first amplitude according to a first supply voltage. A latch may be coupled to a resistor of a plurality of resistors coupled in series. One end of the resistor may be configured to provide to the latch a second supply voltage higher than the first supply voltage according to a third supply voltage higher than the second supply voltage, and another end of the resistor may be configured to receive the third supply voltage. The latch may modify the first signal to provide a second signal, according to the second supply voltage. An amplifier may amplify the second signal to provide a third signal having a second amplitude larger than the first amplitude, according to the third supply voltage.

A multiple operating-mode comparator system can be useful for high bandwidth and low power automated testing. The system can include a gain stage configured to drive a high impedance input of a comparator output stage, wherein the gain stage includes a differential switching stage coupled to an adjustable impedance circuit, and an impedance magnitude characteristic of the adjustable impedance circuit corresponds to a bandwidth characteristic of the gain stage. The comparator output stage can include a buffer circuit coupled to a low impedance comparator output node. The buffer circuit can provide a reference voltage for a switched output signal at the output node in a higher speed mode, and the buffer circuit can provide the switched output signal at the output node in a lower power mode.

A chip with pad tracking having an input/output buffer (I/O buffer), a pad, and a bias circuit. The I/O buffer is powered by a first power and is coupled to the pad. The pad is coupled to the system power. The bias circuit generates a bias signal to be transferred to the I/O buffer to block a leakage path within the I/O buffer when the system power is on and the first power is off. The bias circuit is a voltage divider which generates a divided voltage as the bias signal. In an example, the bias circuit is powered by a second power that is independent from the first power and is not drawn from the pad. In another example, a power terminal of the bias circuit is coupled to an electrostatic discharging bus, and the pad is coupled to the electrostatic discharging bus through a diode.

A chip with pad tracking having an input/output buffer (I/O buffer), a pad, and a bias circuit. The I/O buffer is powered by a first power and is coupled to the pad. The pad is coupled to the system power. The bias circuit generates a bias signal to be transferred to the I/O buffer to block a leakage path within the I/O buffer when the system power is on and the first power is off. The bias circuit is a voltage divider which generates a divided voltage as the bias signal. In an example, the bias circuit is powered by a second power that is independent from the first power and is not drawn from the pad. In another example, a power terminal of the bias circuit is coupled to an electrostatic discharging bus, and the pad is coupled to the electrostatic discharging bus through a diode.

A delay circuit applies a one sample delay to a first digital sinusoid signal and outputs a delayed digital sinusoid signal. The first digital sinusoid signal and the delayed digital sinusoid signal are then added to each other by an adder circuit to generate an added digital sinusoid signal. A gain scaling circuit applies a scaling factor to the added digital sinusoid signal to generate a second digital sinusoid signal. Samples of the first and second digital sinusoid signals are alternately selected by a multiplexing circuit to generate a third digital sinusoid signal having twice as many samples as the first digital sinusoid signal over a same sinusoid period.

A delay circuit applies a one sample delay to a first digital sinusoid signal and outputs a delayed digital sinusoid signal. The first digital sinusoid signal and the delayed digital sinusoid signal are then added to each other by an adder circuit to generate an added digital sinusoid signal. A gain scaling circuit applies a scaling factor to the added digital sinusoid signal to generate a second digital sinusoid signal. Samples of the first and second digital sinusoid signals are alternately selected by a multiplexing circuit to generate a third digital sinusoid signal having twice as many samples as the first digital sinusoid signal over a same sinusoid period.

Provided is a booster circuit enabling improvement of efficiency of a stress test for a circuit to which a boosted voltage is applied. A voltage divider circuit is configured to have a voltage-dividing ratio that is variable depending on a test signal, and a limiter circuit is configured to clamp a voltage to a voltage higher than a boosted voltage in normal operation. In a test mode, the voltage divider circuit is controlled so that the boosted voltage becomes higher than that in the normal operation, and the limiter circuit clamps the boosted voltage, with the result that a booster section continuously operates.

A delay circuit applies a one sample delay to a first digital sinusoid signal and outputs a delayed digital sinusoid signal. The first digital sinusoid signal and the delayed digital sinusoid signal are then added to each other by an adder circuit to generate an added digital sinusoid signal. A gain scaling circuit applies a scaling factor to the added digital sinusoid signal to generate a second digital sinusoid signal. Samples of the first and second digital sinusoid signals are alternately selected by a multiplexing circuit to generate a third digital sinusoid signal having twice as many samples as the first digital sinusoid signal over a same sinusoid period.

A delay circuit applies a one sample delay to a first digital sinusoid signal and outputs a delayed digital sinusoid signal. The first digital sinusoid signal and the delayed digital sinusoid signal are then added to each other by an adder circuit to generate an added digital sinusoid signal. A gain scaling circuit applies a scaling factor to the added digital sinusoid signal to generate a second digital sinusoid signal. Samples of the first and second digital sinusoid signals are alternately selected by a multiplexing circuit to generate a third digital sinusoid signal having twice as many samples as the first digital sinusoid signal over a same sinusoid period.