Output buffer circuit eliminating high voltage insulated transistor and level shift circuit, and an electronic device using the output buffer circuit

Abstract

A novel output buffer circuit including an input circuit, a voltage generating circuit, and an output circuit forms a three-state buffer circuit. The output circuit includes a first transistor, a second transistor, a third transistor, and a fourth transistor. With such a configuration, a simple circuit using no high voltage insulated transistors and level shift circuits can be made, and the simple circuit can output either a low voltage signal or a high voltage signal responsive to a low voltage input signal, reduce the manufacturing cost and the delay of the risetime of the output signal, which are associated with a high voltage insulated transistor. Furthermore, cost can be reduced by miniaturization of the circuit size.