How to interface with ultra-low voltage microcontrollers?
The PSoC CPU does not actually run from 0.5v. Its minimum running voltage is 1.8v. However, the chip also contains a high efficiency boost regulator which works down to 0.5v and can boost that voltage up to the 1.8v that the PSoC requires. The boost converter can supply upto 50mA current, which can be used by the rest of the circuit.