Circuit and method of operating a low-noise, on-demand regulator in switched or linear mode

摘要

A dual mode voltage converter (18) is provided which is capable of performing linear or switched modes of operation based on an external mode select signal presented to terminal (MODE). Pulse width modulation techniques are used to regulate voltage delivered to output terminal (Vout) when a mode control signal is present at terminal (MODE) and linear conversion techniques are used in the absence of the mode control signal. Stability of voltage converter (18) is enhanced during linear conversion mode by shorting switch (60) and BW rolloff circuit (44). An alternate embodiment of dual mode voltage converter (18) provides operation based on an internal mode select signal.