High-to-low voltage level shifter without quiescent current using a low voltage CMOS (complementary metal-oxide semiconductor) process
Original Publication Date: 2001-Oct-01
Included in the Prior Art Database: 2003-Jul-23
Enhancement in integrated circuit technology has led to a shrink in feature size of the active devices, which in company with the need for a reduction of power consumption led to a reduction of the supply voltage of integrated circuits (ICs). Widely accepted values for the supply voltage of modern ICs are 3.3V or 2.5V. On the other hand, many other components used by systems still operate on a higher supply vol- tage, i.e. 5V. Up to now, the interface problem has been solved by using process technology options, which make high- voltage active devices available. By using thicker gate oxide with these special devices a higher voltage can be applied to their gates. The input section of input-output pad cells is constructed with these speci- al high-voltage transistors, shifting the high-voltage swing at the input to a low-voltage swing, which can be applied to the core.