According to one or more aspects of DC-to-DC voltage conversion as taught herein, a DC-to-DC converter selectively operates in a first mode wherein an included linear pass output circuit supplies the output power from the DC-to-DC converter, in a second mode wherein an included charge pump output circuit supplies the output power, and in a third mode wherein the linear pass and charge pump output circuits operate in parallel to supply the output power. With this third mode, also referred to as a “dual” mode, wherein the linear pass and charge pump output circuits operate in parallel, the DC-to-DC converter keeps the more efficient output circuit on after it has begun switching to operation with the less efficient output circuit. Such switchover may be performed dynamically in response to changing operating conditions. Detected operating conditions may include input voltages, output voltages, and output load conditions.