Sub-threshold level converter with internal supply feedback for multi-voltage applications

A new sub-threshold level shifter for ultra-low voltage digital systems is presented in this study. The self-controlled supply feedback loop is quintessential for this circuit. Measured results from a test chip show that it is capable of realising a voltage conversion from a voltage as low as 0.1-1.2 V reliably, while maintaining an operational frequency of 25.2 kHz, when implemented in a 65-nm process technology. In addition, it also has ample process variation tolerance and low static power consumption. To support multi-voltage digital systems, the proposed level converter can up-convert an input at any voltage with this range to normal voltage domains.