Examples of a signal calculator include a voltage multiplier and a time divider. The voltage multiplier copies time information corresponding to a first voltage and generates a third voltage using a second current corresponding to a second voltage during a first period corresponding to the copied time information. The time divider generates an output according to a result of comparing a voltage generated by a first current on the basis of a voltage corresponding to a first time with a second voltage corresponding to a second time.

A pulse-width modulation circuit includes an oscillator stage. The oscillator stage includes a first voltage comparator having a first input terminal, a second input terminal and an output terminal. A first capacitor is coupled to the first input terminal of the first voltage comparator. A charging path for the first capacitor is coupled between the first capacitor and the output terminal of the first voltage comparator, the charging path having a first resistance. A discharging path for the first capacitor is coupled between the first capacitor and the output terminal of the first voltage comparator, the discharging path having a second resistance that is different from the first resistance. A duty cycle of a clock signal generated by the oscillator stage is determined based on a first RC time constant for charging the first capacitor and a second RC time constant for discharging the first capacitor.

A pulse-width modulation circuit includes an oscillator stage. The oscillator stage includes a first voltage comparator having a first input terminal, a second input terminal and an output terminal. A first capacitor is coupled to the first input terminal of the first voltage comparator. A charging path for the first capacitor is coupled between the first capacitor and the output terminal of the first voltage comparator, the charging path having a first resistance. A discharging path for the first capacitor is coupled between the first capacitor and the output terminal of the first voltage comparator, the discharging path having a second resistance that is different from the first resistance. A duty cycle of a clock signal generated by the oscillator stage is determined based on a first RC time constant for charging the first capacitor and a second RC time constant for discharging the first capacitor.

A spread spectrum clock generator circuit includes a phase comparator; an oscillator to output an output clock signal; a phase selector to select one of phases equally dividing one cycle of the output clock signal, and to generate a phase shift clock signal having a rising edge in the selected phase; and a phase shift controller to control the phase selector. The phase shift controller generates a variable phase shift amount; determines the phase of the rising edge so that the cycle of the phase shift clock signal has a length changed from the cycle of the output clock signal by the variable phase shift amount added with a fixed phase shift amount; and changes a setting of an SS modulation profile if the selected phase exceeds an upper limit, falls below a lower limit, or is within the upper and lower limits.

The present invention provides an output buffer including a first transistor, a second transistor and a pad-tracking circuit is disclosed. The first transistor is coupled between a supply voltage and an output node, wherein the output node is coupled to a pad. The second transistor is coupled between the output node and a reference voltage. The pad-tracking circuit is coupled to the control circuit and the first transistor, and is configured to generate a gate control signal to a gate electrode of the first transistor. The output buffer is selectively operated in an input mode and a fail-safe mode, and when the output buffer switches between the input mode and the fail-safe mode and the supply voltage of the first transistor ramps up or ramps down, the pad-tracking circuit generates the gate control signal to the gate electrode of the first transistor according to the voltage of the pad.

The present invention provides an output buffer including a first transistor, a second transistor and a pad-tracking circuit is disclosed. The first transistor is coupled between a supply voltage and an output node, wherein the output node is coupled to a pad. The second transistor is coupled between the output node and a reference voltage. The pad-tracking circuit is coupled to the control circuit and the first transistor, and is configured to generate a gate control signal to a gate electrode of the first transistor. The output buffer is selectively operated in an input mode and a fail-safe mode, and when the output buffer switches between the input mode and the fail-safe mode and the supply voltage of the first transistor ramps up or ramps down, the pad-tracking circuit generates the gate control signal to the gate electrode of the first transistor according to the voltage of the pad.

This disclosure relates to a signal generating circuit and an audio processing device. The circuit includes a switch module, a voltage producing module, and a signal generating module; the switch module is connected to the voltage producing module, including at least one control switch, and is used for receiving a frequency division signal. Based on the frequency division signal, the at least one control switch is turned on or turned off; the voltage producing module is separately connected to the switch module and the signal generating module and used for producing a first voltage and a second voltage. The at least one control switch controls the first voltage and the second voltage to change. The signal generating module is connected to the voltage producing module and used for generating a carrier signal with the same frequency as the frequency division signal according to the received first and second voltages.

Aspects of the disclosure provide for a circuit. In some examples, the circuit includes a first charging path including a first capacitor coupled to a first output node. The circuit further includes a second charging path comprising a first switch and a second capacitor. The circuit further includes a third charging path comprising a second switch and a third capacitor. The circuit further includes a first discharging path comprising the second capacitor, a third switch coupled between the second charging path and a second output node, and a fourth switch coupled between the second charging path and a fourth node. The circuit further includes a second discharging path comprising the third capacitor, a fifth switch coupled between the third charging path and the second output node, and a sixth switch coupled between the third node and the fourth node.

Aspects of the disclosure provide for a circuit. In some examples, the circuit includes a first charging path including a first capacitor coupled to a first output node. The circuit further includes a second charging path comprising a first switch and a second capacitor. The circuit further includes a third charging path comprising a second switch and a third capacitor. The circuit further includes a first discharging path comprising the second capacitor, a third switch coupled between the second charging path and a second output node, and a fourth switch coupled between the second charging path and a fourth node. The circuit further includes a second discharging path comprising the third capacitor, a fifth switch coupled between the third charging path and the second output node, and a sixth switch coupled between the third node and the fourth node.

A power supply for supplying a power to a heating mechanism used for heating a measurement target that emits a measurement signal includes an input device configured to output an input signal that reflects a control signal in a differentiable periodic waveform having a frequency of 1 kHz or less. The power supply includes a switching amplifier configured to amplify the input signal from the input device and output the amplified signal.