Level shifter with zero threshold device for ultra-deep submicron CMOS designs

摘要

A new level shifting circuit, using a zero threshold voltage device, is described. An input swings between a low supply and ground. An output swings between a high supply and ground. An inverter has input connected to the input of the level shifting circuit and output forming an inverted level shifting input. A first NMOS transistor has the gate connected to the level shifting input and the source connected to ground. A first zero threshold NMOS transistor has the gate connected to a low bias voltage and the source connected to the first NMOS transistor drain. A first PMOS transistor has the gate connected to the level shifting output, the source connected to the high supply, and the drain connected to the first zero threshold NMOS transistor drain. A second NMOS transistor has the gate connected to the inverted level shifting input and the source connected to ground. A second zero threshold NMOS transistor has the gate connected to the low bias voltage, the source connected to the second NMOS transistor drain, and the drain connected to the level shifting output. A second PMOS transistor has the gate connected to the first zero threshold NMOS transistor drain, the source connected to the high supply, and the drain connected to the level shifting output.