Schmitt trigger circuit realized with low-voltage devices for high-voltage signal application

摘要

The present invention relates to a Schmitt trigger circuit. The proposed Schmitt trigger circuit can receive the high-voltage input signal but it is consisted by only using the low-voltage devices with thin gate oxide. For example, it is implemented in a 0.13 mum 1V/2.5V Complementary Metal-Oxide Semiconductor (CMOS) process. However, it can be operated in the 3.3 V interface environment without causing the high-voltage-induced gate-oxide reliability problem. It is suitable for the I/O interface circuit to receive the high-voltage input signal and to reject the noise.