Power supply generator with noise cancellation

摘要

Techniques for performing noise cancellation/attenuation are disclosed. In one design, an apparatus includes a power supply generator having a switcher, a coupling circuit, an envelope amplifier, and a feedback circuit. The switcher generates DC and low frequency components and the envelope amplifier generates high frequency components of a supply voltage for a load, e.g., a power amplifier. The switcher receives a first supply voltage and provides a switcher output signal having switcher noise. The coupling circuit receives the switcher output signal and provides a first output signal having a first version of the switcher noise. The feedback circuit receives the switcher output signal and provides a feedback signal. The envelope amplifier receives an envelope signal and the feedback signal and provides a second output signal having a second version of the switcher noise, which is used to attenuate the first version of the switcher noise at the load.

主权项

1. An apparatus comprising:
a first circuit configured to receive a first input signal comprising noise and to provide a first output signal comprising a first version of the noise; a feedback circuit having an input coupled to an input of the first circuit and configured to receive the first input signal independent of the first circuit and provide a feedback signal; and a second circuit configured to receive a second input signal and the feedback signal and to provide a second output signal comprising a second version of the noise used to attenuate the first version of the noise.