The development of low-voltage and low-power design techniques is observed since several decades, as system power constraints and advanced deeply-scaled CMOS technologies require lower and lower supply voltages. It is predicted that the supply voltage for high performance microprocessors will be decreased to 0.6 V in a near future. Even lower supply voltage may be requested for low-power systems, especially the ones applied in biomedical implantable or wearable electronic devices, autonomous sensor nodes supplied with non-conventional energy sources and other similar applications. The requested parameters of low-voltage and low-power systems are often difficult to achieve with the use of traditional design techniques. Therefore, the circuit and system designers are seeking to develop novel architectural solutions capable to operate with low supply voltage, while maintaining acceptable performances.