Abstract: A voltage regulator circuit is disclosed. In one embodiment, a low drop-out (LDO) voltage regulator includes a voltage loop and a current loop. The current loop includes a source follower coupled to an output node of the LDO voltage regulator, the source follower being implemented with a PMOS transistor. The current loop also includes a current mirror coupled between a first branch of the current loop and a second branch of the current loop. The source follower is implemented in the second branch of the current loop. The voltage loop includes an amplifier circuit having an inverting input coupled to the output node, and a non-inverting input coupled to receive a reference voltage. The output of the amplifier is coupled to the gate terminal of the PMOS transistor of the current mirror.

Abstract: A voltage regulator is disclosed. The voltage regulator is cascaded, including first and second stages. The first stage may be a capacitor-less first stage that includes a source follower implemented with a first PMOS transistor, with the first PMOS transistor receiving a first reference voltage on its respective gate terminal. The first stage is coupled to receive a first voltage from an external voltage supply, and to provide a second voltage to the second stage. The second stage may be directly and exclusively coupled to the first stage, with no capacitor or connection for one coupled to the first stage output. The second stage may provide an output voltage, on an output node, with the output voltage being less than the second voltage.

Abstract: An acoustic object detector for detecting presence of an acoustic signal is provided. The acoustic object detector includes a number of bandpass filters. Each bandpass filter is configured to convert an input signal into an analog signal within a frequency band. The acoustic object detector also includes a number of spike generating circuits each coupled to the respective bandpass filter. Each spike generating circuit is configured to generate a series of spike signals based upon an adaptive threshold for the analog signal. The acoustic object detection further includes a decision circuit configured to generate a digital signal at a time-frequency point from the series of spike signals.

Abstract: A wireless power transfer system using a resonant rectifier circuit with capacitor sensing. A wireless power transfer system includes a power receiver resonant circuit and a synchronous rectifier. The power receiver resonant circuit includes an inductor and a capacitor connected in series with the inductor. The synchronous rectifier is configured to identify zero crossings of alternating current flowing through the inductor based on voltage across the capacitor, and control synchronous rectification of the alternating current based on timing of the zero crossings.

Abstract: A wireless power transfer system includes a wireless power receiver having a rectifier. The rectifier includes switches. The wireless power receiver is operable to control the switches for ensuring a complex impedance at the input of the rectifier.

Abstract: In described examples, a switching mode power supply includes an output filter, a driver, a pulse width modulator, and pulse adaptation circuitry. The output filter is configured to provide output of the switching mode power supply. The driver is coupled to the output filter and is configured to switch current to the output filter. The pulse width modulator is configured to generate pulses that control switching of current by the driver. The pulse width modulator includes spread spectrum logic configured to randomize timing of the pulses generated by the pulse width modulator. The pulse adaptation circuitry is configured to identify an instantaneous excursion of the output of the switching mode power supply beyond a predetermined threshold, and to modify the randomized timing of the pulses produced by the pulse width modulator based on the identified instantaneous excursion.

Abstract: A wireless power transfer system includes a wireless power receiver having a rectifier. The rectifier includes switches. The wireless power receiver is operable to control the switches for ensuring a complex impedance at the input of the rectifier.

Abstract: In described examples, a switching mode power supply includes an output filter, a driver, a pulse width modulator, and pulse adaptation circuitry. The output filter is configured to provide output of the switching mode power supply. The driver is coupled to the output filter and is configured to switch current to the output filter. The pulse width modulator is configured to generate pulses that control switching of current by the driver. The pulse width modulator includes spread spectrum logic configured to randomize timing of the pulses generated by the pulse width modulator. The pulse adaptation circuitry is configured to identify an instantaneous excursion of the output of the switching mode power supply beyond a predetermined threshold, and to modify the randomized timing of the pulses produced by the pulse width modulator based on the identified instantaneous excursion.

Abstract: An acoustic object detector for detecting presence of an acoustic signal is provided. The acoustic object detector includes a number of bandpass filters. Each bandpass filter is configured to convert an input signal into an analog signal within a frequency band. The acoustic object detector also includes a number of spike generating circuits each coupled to the respective bandpass filter. Each spike generating circuit is configured to generate a series of spike signals based upon an adaptive threshold for the analog signal. The acoustic object detection further includes a decision circuit configured to generate a digital signal at a time-frequency point from the series of spike signals.