A 63-μW standby power microcontroller with on-chip hybridregulator scheme

Presents a 32-b RISC microcontroller having an on-chip dc-dc converter. The chip standby power including the dc-dc converter is reduced to 63 μW with a new hybrid regulator scheme in which the microcontroller selects a switching regulator in active mode and a series regulator in standby mode. The achieved standby power corresponds to only about 1% of the standby power with a conventional scheme which always uses a switching regulator. Off-chip power transistor-type configuration suppresses pin-count increase caused by implementing an on-chip switching regulator. A series regulator that could be used instead of the switching regulator in active mode was also implemented on the chip. The series regulator does not impact the chip size because it is divided and inserted into I/O area that was originally left unused