An open loop envelope tracking system calibration technique and circuitry are proposed. A radio frequency power amplifier receives a modulated signal. An envelope tracker power converter generates a modulated power amplifier supply voltage for the radio frequency power amplifier based on a control signal derived from the modulated signal. A first output power and a second output power of the radio frequency power amplifier are measured when the control signal is respectively delayed by a first delay period and a second delay period. A sensitivity of the output power of the radio frequency power amplifier is near a maximum near the first delay period and the second delay period. The first delay period and/or the second delay period are adjusted until the first output power substantially equals the second output power. The first delay period and the second delay period are used to obtain a calibrated fine tuning delay offset.

Group delay calibration method for power amplifier envelope tracking

Embodiments disclosed in the detailed description relate to a pseudo-envelope follower power management system used to manage the power delivered to a linear RF power amplifier.

Pseudo-envelope following power management system

Configuration-feedback circuitry and transceiver circuitry are disclosed. The configuration-feedback circuitry regulates an output power from a radio frequency power amplifier based on a difference between a target output power from the radio frequency power amplifier and a measured output power from the radio frequency power amplifier. The transceiver circuitry regulates a modulated power supply voltage, which is used by the radio frequency power amplifier to provide power for amplification, based on the difference between the target output power from the radio frequency power amplifier and the measured output power from the radio frequency power amplifier.

Power loop control based envelope tracking

A direct current (DC)-DC converter, which includes a parallel amplifier, a radio frequency (RF) trap, and a switching supply, is disclosed. The switching supply includes switching circuitry and a first inductive element. The parallel amplifier has a feedback input and a parallel amplifier output. The switching circuitry has a switching circuitry output. The first inductive element is coupled between the switching circuitry output and the feedback input. The RF trap is coupled between the parallel amplifier output and a ground.

Noise reduction for envelope tracking

A switch mode power supply converter and a parallel amplifier are disclosed. The switch mode power supply converter is coupled to a modulated power supply output and the parallel amplifier has a parallel amplifier output coupled to the modulated power supply output. Further, the parallel amplifier has a group of output stages, such that each output stage is directly coupled to the parallel amplifier output and each output stage receives a separate supply voltage.

Multiple power supply input parallel amplifier based envelope tracking

Systems and methods are disclosed to detect current for an output load with an inductor. The system includes a high side power transistor a low side power transistor coupled to the high side power transistor; and a controller coupled to the high and low side power transistors to provide cycle by cycle conduction of the low side power transistor, said controller adaptively turning off the low side power transistor when the high and low side power transistors are off and an inductor current is non-positive. Adaptation of the turn off of the low side transistor is based on the time position of the detection of the non-positive inductor current and serves to improve the power efficiency of the system.

Adaptive non-positive inductor current detector (anpicd)

A current detector for an output load includes a high side power transistor; a low side power transistor coupled to the high side power transistor; and a controller coupled to the high and low side power transistors to provide cycle by cycle control of the conduction of the high and low side power transistors, wherein if the controller detects zero or negative current in the output inductor, using a dead time between when the low side power transistor turns off and before the high side power transistor turns on, the low side power transistor is held off during the entirety of the next switching cycle.

Andrew Wu

Papers

Adaptive non-positive inductor current detector (anpicd)

Non-positive inductor current detector for step down switching regulators