Apparatus and method for DC-to-DC power conversion

A method of generating an output signal at a regulated voltage as a combination of first and second signals, the method comprising:

• generating the first signal using a linear regulator circuit having a first power conversion efficiency and configured to supply higher frequency current components of the output signal;
• generating a second signal using a switching regulator circuit having a second power conversion efficiency relatively higher than the first power conversion efficiency and configured to supply lower frequency and DC current components of the output signal;
• and
• combining the first and second regulated signals to form the output signal.

A radio base station (RBS) for use in a wireless communication network, the RBS comprising:

• signal processing resources to perform at least one of transmit signal processing and receive signal processing;
• and
• at least one DC-to-DC converter for powering at least a portion of the signal processing resources, said DC-to-DC converter comprising:
• a linear regulator circuit to generate a first signal having higher frequency transient current components;
• a switching regulator circuit in parallel with the linear regulator circuit to generate a second signal having lower frequency and DC current components;
• a summing node to combine the first and second signals to form an output signal having a regulated voltage;
• and
• wherein the linear regulator circuit supplies a majority of transient current required by the signal processing resources powered by the output signal, and the switching regulator circuit provides a majority of steady-state current required by the signal processing resources powered by the output signal.