In an embodiment, a method includes: receiving a main supply voltage; generating a first regulated output voltage with a DC-DC converter; providing the main supply voltage to a driver of a control terminal of an output transistor of an LDO; receiving, at an input terminal of the LDO, the first regulated output voltage; generating, at an output terminal of the LDO, a second regulated output voltage from the first regulated output voltage; and when the main supply voltage falls below a predetermined threshold, discharging a capacitor coupled to the input terminal of the LDO by activating a switch coupled to the input terminal of the LDO.

An interface performs power delivery and communication with an external apparatus. A convert device is configured to convert a voltage of input power that is supplied from the external apparatus through the interface. A convert device includes a first convert device having first conversion efficiency and a second convert device having second conversion efficiency different from the first conversion efficiency. A processing device is configured to operate by using power converted by the convert device. A controller is configured to switch a conversion state between: a first conversion state of converting, by the first convert device, the input power supplied from the external apparatus through the interface and supplying the converted input power to the processing device; and a second conversion state of converting, by the second convert device, the input power supplied from the external apparatus through the interface and supplying the converted input power to the processing device.

A fast-switching power management circuit operable to prolong battery life is provided. The power management circuit includes a voltage circuit that can generate an output voltage for amplifying an analog signal in a number of time intervals and a pair of hybrid circuits each causing the output voltage to change in any of the time intervals. A control circuit is configured to activate any one of the hybrid circuits during a preceding one of the time intervals to cause the output voltage to change in an immediately succeeding one of the time intervals. By starting the output voltage change earlier in the preceding time interval, it is possible to complete the output voltage change within a switching window in the succeeding time interval while concurrently reducing rush current associated with the output voltage change, thus helping to prolong battery life in a device employing the power management circuit.

In an embodiment, an apparatus is disclosed that includes a power management integrated circuit (PMIC). The PMIC includes a voltage regulator supplied by a first power source and configured to generate a first output and a charge pump supplied by a second power source and configured to generate a second output. A bias voltage output of the power management integrated circuit is generated based at least in part on the first output and the second output. The charge pump is configured to adjust the second output based at least in part on a comparison between the bias voltage output and a reference voltage.

An example electronic device includes an antenna; a switching regulator; a communication chip including an amplifier, a first linear regulator operably connected to the amplifier and the switching regulator and configured to be supplied with a first voltage from the switching regulator, and a second linear regulator operably connected to the amplifier and the switching regulator and configured to be supplied with a second voltage higher than the first voltage from the switching regulator, the communication chip configured to transmit a radio-frequency signal outside of the electronic device through the antenna; and a control circuit. The control circuit is configured to produce an envelope of an input signal input to the amplifier in connection with the radio-frequency signal and to provide the produced envelope to at least one of the first linear regulator or the second linear regulator. The first linear regulator is configured to provide a third voltage corresponding to the envelope to the amplifier using the first voltage based on the envelope having a voltage in a first range. The second linear regulator is configured to provide a fourth voltage higher than the third voltage to the amplifier using the second voltage based on the voltage of the envelope being in a second range including values larger than values included in the first range.

A single inductor multiple output DC-to-DC converter may be configured as a buck-boost converter. The converter may include an inductor, a plurality of switches coupled to the inductor to control energizing and deenergizing phases of the inductor, and a plurality of output rails. Each of the plurality of output rails may include at least one switch, which is configured to connect the output rail to the inductor of the buck-boost converter. Depending on the energizing and deenergizing patterns of the inductor, and the state of the one or more switches, the various output rails may be supplied with a plurality of different output voltages and / or output currents. Any of a plurality of regulating strategies may be utilized to further control the output voltages and / or the output currents.

Described embodiments include a circuit for reducing output voltage noise in a voltage regulator includes an amplifier having first and second amplifier inputs, a compensation terminal and an amplifier output. The first amplifier input is coupled to a reference voltage terminal, and the compensation terminal coupled to an output terminal. A buffer amplifier has a buffer input and a buffer output, and the buffer input is coupled to the amplifier output. A first transistor is coupled between a supply voltage terminal and the output terminal, and has a first control terminal that is coupled to the buffer output. A boost current injection circuit has a boost input and a boost output, and the boost input is coupled to the supply voltage terminal. A second transistor is coupled between the boost output and the compensation terminal, and has a second control terminal.

An auxiliary power supply circuit operating within a wide input voltage range has a voltage follower unit and a voltage comparison unit. The voltage follower unit has an electronic switch, a resistor, and a Zener diode. The electronic switch has a first terminal electrically connected to a voltage input terminal of the working voltage conversion circuit, a second terminal electrically connected to a voltage output terminal of the working voltage conversion circuit, and a control terminal. The resistor is electrically connected between the first terminal and the control terminal of the electronic switch. The Zener diode has a cathode electrically connected to the control terminal of the electronic switch. The voltage comparison unit has a detecting terminal electrically connected to the voltage input terminal of the working voltage conversion circuit, and an output terminal electrically connected to the control terminal of the electronic switch.

In some embodiments, a power supply system for a power amplifier can include a voltage converter implemented generate a first voltage at an output node, and an envelope following circuit implemented to generate and combine a second voltage with the first voltage to provide a combined output voltage for the power amplifier. The combined output voltage can have a waveform that follows one or more peaks of an envelope of a radio-frequency signal above the first voltage.

Circuits and methods for providing a “bootstrap” power supply for level-shifter/driver (LS/D) circuits in a FET-based power converter. In a first embodiment, linear regulators and a bootstrap capacitor provide a bootstrap power supply for level-shifter/driver circuits in each tier of a multi-level FET-based power converter. In a second embodiment, floating charge circuits and bootstrap capacitors provide an improved bootstrap power supply for level-shifter and driver circuits in each tier of a multi-level FET-based power converter. More particularly, a floating charge circuit configured to be coupled to an associated bootstrap capacitor includes a first sub-circuit configured to pre-charge the associated bootstrap capacitor when coupled and a second sub-circuit configured to transfer charge between the bootstrap capacitor and a bootstrap capacitor coupled to an adjacent floating charge circuit.