Abstract: A power supply device includes a pulse frequency modulation controller circuitry and a cycle controller circuitry. The pulse frequency modulation controller circuitry is configured to adjust a transiting speed of a first signal according to at least one control bit, and to compare the first signal with a first reference voltage to generate a second signal, and to generate a driving signal to a power converter circuit according to an output voltage, a second reference voltage, and the second signal, in which the power converter circuit is configured to generate the output voltage according to the driving signal. The cycle controller circuitry is configured to detect a frequency of the driving signal according to a clock signal having a predetermined frequency, in which the predetermined frequency is set based on a frequency range capable of being heard by humans.

Abstract: Aspects of the technology described herein relate to control circuitry configured to turn on and off the ADC driver. In some embodiments, the control circuitry is configured to turn on and off the ADC driver in synchronization with sampling activity of an ADC, in particular based on when an ADC is sampling. The control circuitry may be configured to turn on the ADC driver during the hold phase of the ADC a time period before the track phase and to turn off the ADC driver during the hold phase a time period after the track phase. In some embodiments, the control circuitry is configured to control a duty cycle of the ADC driver turning on and off. In some embodiments, the control circuitry is configured to control a ratio between an off current and an on current in the ADC driver.

Abstract: An operational amplifier with one or more fully-differential amplifier stages has a common-mode control input. A low-frequency feedback control path is coupled between an output of the fully-differential amplifier stages and the common-mode control input to control low-frequency drift of the common-mode voltage of the output of the stages. A high-frequency feed-forward control path couples a pair of inputs of the stages to control high-frequency ripple of a common-mode voltage of the inputs of the stages. One or more of the differential amplifier stages may have a bias input that controls a direct-current (DC) bias voltage of gates of pull-up transistors of the stage that is both DC and capacitively coupled to the gates so that the stage operates with class A bias at DC and with class AB bias at high frequencies.

Abstract: A temperature sensing circuit includes a current source circuit, a resistor, a bandgap voltage generation circuit, a voltage-equalizing circuit and a temperature determining circuit. The current source circuit has a first current output terminal and a second current output terminal. The bandgap voltage generation circuit includes a pair of bipolar junction transistors. The voltage-equalizing circuit equalizes voltages of a first current output terminal and the second current output terminal. The temperature determining circuit includes a sampling capacitor and a calculation circuit. The sampling capacitor samples a first voltage of a first terminal of the resistor and a second voltage of a second terminal of the resistor. The calculation circuit generates a temperature value by calculating a voltage difference between the first voltage and the second voltage.

Abstract: An interface electronic circuit between an energy harvesting stage is provided with an inductor and a charging stage, the interface electronic circuit having a regulation circuit capable of servo-controlling an average input impedance value of the interface electronic circuit to a predetermined optimum impedance value.