Techniques are described for using valley detection for supply voltage modulation in power amplifier circuits. Embodiments operate in context of a power amplifier circuit configured to be driven by a supply voltage generated by a supply modulator and to receive an amplitude-modulated (AM) signal at its input. The output of the power amplifier circuit can be fed to a valley detector that can detect a valley level corresponding to the bottom of the envelope of the AM signal. The detected valley level can be fed back to the supply modulator and compared to a constant reference. In response to the comparison, the supply modulator can vary the supply voltage to the power amplifier circuit in a manner that effectively tracking the envelope of the power amplifier circuit's output signal, thereby effectively seeking a flat valley for the output signal's envelope.

Apparatus and methods for power amplifier power management are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a radio frequency signal, a front-end system including a first power amplifier module that amplifies the radio frequency signal, and a power management system including an envelope tracking power management unit that provides an envelope tracking supply voltage to the first power amplifier module, and a first average power tracking power management unit that provides an average power tracking supply voltage to the first power amplifier module. The first power amplifier module is configured to selectively switch between the envelope tracking supply voltage and the average power tracking supply voltage.

Apparatus and methods for power amplifier power management are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a radio frequency signal, a front-end system including a first power amplifier module that amplifies the radio frequency signal, and a power management system including an envelope tracking power management unit that provides an envelope tracking supply voltage to the first power amplifier module, and a first average power tracking power management unit that provides an average power tracking supply voltage to the first power amplifier module. The first power amplifier module is configured to selectively switch between the envelope tracking supply voltage and the average power tracking supply voltage.

A circuit to modulate the power supply to track input or output voltages provided to or output by a plurality of amplifiers to reduce power dissipation is provided. The circuit may include a peak detection circuit configured to receive a plurality of voltages respectively corresponding to the plurality of amplifiers, and to detect and output information regarding a maximum instantaneous voltage from the received plurality of voltages, and a summing circuit configured to output a sum of the information regarding the maximum instantaneous voltage and an amplifier headroom voltage. A reference voltage may be provided for the supply voltage responsive to the output sum. The circuit may also include a scaling circuit configured to scale the output sum, and the reference voltage may be a scaled reference voltage output by the scaling circuit.

A current source and/or current sink digital-to-analog converter (DAC) includes a DAC circuit that converts a digital code to an analog current or voltage signal, an optional transconductance circuit that converts a voltage output of the DAC circuit into a current signal, and an output circuit that amplifies a current output of the DAC circuit or optionally amplifies a current output of the transconductance circuit to set a desired high current output for application to an output of the current source and/or current sink DAC. A power supply control current may be coupled to a power supply circuit that supplies power to the output circuit of the current source and/or current sink DAC. The power supply control current adjusts the output of the power supply circuit to cause the current source and/or current sink DAC to operate at a higher power efficiency.

A wireless power transmitting system includes a power amplifier comprising a plurality of measurement points and a power amplifier controller integrated circuit (IC). In some embodiments, the power amplifier controller IC performs synchronization of the various components of the power amplifier, conducts impedance and temperature measurements at the measurements points, determines if a foreign object is within the transmission range of the wireless power transmitter, and decides if a shutdown of the power amplifier is needed. In some embodiments, the power amplifier controller IC determines through a transmitter controller IC, the presence of a foreign object within the transmission range and adjusts the power transmission to one or more receivers.

A DC-to-DC voltage regulator circuit comprising: an output node; a pull-up switch and a pull-down switch with an output node coupled between them; a reactive circuit element coupled to the output node; a pull-up setting voltage circuit coupled to provide a pull-up setting voltage that is a function of a voltage at the output node; a pull-down setting voltage circuit coupled to provide a pull-down setting voltage that is a function of the voltage at the output node; a first comparator coupled to cause the pull-up switch to transition between open switch state and its closed switch state based upon a comparison of the pull-up setting voltage and a control voltage; and a second comparator coupled to cause the pull-down switch to transition between its open switch state and its closed switch state.

A mobile device may include a power supply configured to generate a supply voltage, a power converter configured to generate a converted voltage from the supply voltage wherein the converted voltage is significantly different than the supply voltage, and a plurality of power domains. The plurality of power domains may include a first power domain global to the mobile device and comprising a first plurality of electronic components powered from the supply voltage and a second power domain global to the mobile device and comprising a second plurality of electronic components powered from the converted voltage, wherein power requirements of each of the second plurality of electronic components are significantly higher than power requirements of each of the first plurality of electronic components.

A power supply configured to supply a modulated voltage to a power amplifier is shown. The power supply has an alternating current (AC) component generator, a direct current (DC) component generator, and a transition accelerator. The AC component generator generates an AC component of the modulated voltage according to an envelope tracking signal. The DC component generator generates a DC component of the modulated voltage according to the operational voltage range of the power amplifier. The transition accelerator is coupled to an output terminal of the DC component generator to speed up the transition of the modulated voltage.

A method and system for controlling the switching power supply in a car audio system. The system includes a circuit that detects when the signal voltage is approaching the power supply voltage rails, that is, circuit anticipates the conditions that cause “clipping” of the signal. In response to detecting the pre-clipping condition, the circuit boosts the power supply. Additionally, the inventive system includes a holding circuit for sustaining the boosted power supply for a predetermined period of time. Thus, the power is boosted as needed and remains on for a period of time thereby preventing frequent, repetitive activation of the power supply.