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

Abstract

A new sub-threshold level shifter for ultra-low voltage digital systems is presented in this study. The selfcontrolled 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.

0.5 V bulk ‐ driven CMOS fully differential current feedback operational amplifier

“…However, it is well-known that the threshold voltage of the conventional MOS devices will not decrease following the development of feature size of up to date technologies. There are several techniques to reduce the impact of the threshold voltage of the MOS devices [23][24][25][26][27][28]. This paper is focused on the BD technique which is compatible with standard CMOS technology without the need for expensive low threshold voltage transistors.…”

“…This is due to the increased demand for applications in portable equipment, biomedical devices, bioelectronics and embedded sensor interfaces. Several LV LP active devices have been reported in the technical literature using subthreshold biasing [23], floating-gate [24], bulkdriven (BD) metal oxide semiconductor (MOS) [25], quasifloating-gate [26], BD quasi-floating-gate [27], dynamic threshold MOS [28]. LV LP CFOAs were already proposed in [29][30][31].…”