摘要 |
An apparatus includes an envelope tracking power supply configured to control a power amplifier. The power supply includes a first amplifier configured to receive an input voltage and generate a supply voltage for the power amplifier. The power supply also includes a second amplifier configured to receive a shifted input voltage. An output of the second amplifier is coupled to the first amplifier. The first amplifier is configured to maintain an operational mode of the power amplifier. The power supply could further include a third amplifier. An output of the third amplifier is coupled to an input of the second amplifier, and the third amplifier is configured to receive a second shifted input. |