A new Schmitt trigger circuit in a 0.13 μm 1/2.5 V CMOS process to receive 3.3 V input signals

A new Schmitt trigger circuit, which consists of low-voltage devices, can receive the high-voltage signal without gate-oxide reliability problem, is proposed. The new proposed circuit, which can operate in a 3.3 V signal environment without suffering high-voltage gate-oxide stress, has been fabricated in a 0.13 μm 1/2.5 V CMOS process. The experimental results show that the measured transition threshold voltages of the new proposed Schmitt trigger circuit are about 1 V and 2.5 V, respectively. The proposed Schmitt trigger circuit is suitable for mixed-voltage I/O interfaces circuit to receive the input signals and reject the input noise.