In various embodiments, the envelope tracker further includes a controllable delay circuit configured to control a relative delay between an AC path through the first filter and a DC path through the second filter. According to a number of embodiments, the controllable delay circuit includes a plurality of controllable delay buffers each configured to control a delay of a respective one of the plurality of regulated voltages.

In some embodiments, the DC path filter carries at least seventy five percent of the energy provided from the envelope tracker to the power amplifier supply voltage terminal.

In certain embodiments, the present disclosure relates to a mobile device. The mobile device includes a transceiver configured to generate a radio frequency transmit signal, a front end circuit including a power amplifier configured to amplify the radio frequency transmit signal and to receive power from a power amplifier supply voltage, and a power management circuit including an envelope tracker configured to generate the power amplifier supply voltage based on an envelope signal corresponding to an envelope of the radio frequency transmit signal. The envelope tracker includes a DC-to-DC converter configured to output a plurality of regulated voltages, a modulator configured to generate a modulator output voltage based on the plurality of regulated voltages and the envelope signal, a first filter coupled between the modulator output voltage and the power amplifier supply voltage, and a second filter coupled between a DC voltage and the power amplifier supply voltage.