Schmitt circuit

Abstract

Abstract PURPOSE:To set the high or low level of threshold of a circuit independently, by constituting the circuit with three sets of inverters consisting of complementary IG-FETs and a driver consisting of cascade connection of the IG-FETs. CONSTITUTION:A Schmitt circuit is constituted with three sets of inverters 16-18 consisting of complementary IG-FETs 7, 8-11, 12, and a driver 19 consisting of the cascade connection of P channel IG-FETs 5, 13 and N channel IG-FETs 6, 14. The high level of the threshold TH of the Schmitt circuit is decided with the gm of the FETs 6, 14 of the driver 19 and of a P channel IG-FET9 of an inverter 17, and the low level is the ratio of gm between the FETs 5, 13 of the driver 19 and the N channel IG-FET10 of the inverter 17. The FET14 turns on only when the input level changes from 0 to 1 and the FET13 turns on only when the input level changes from 1 to 0, then the high level of the TH of the Schmitt circuit is obtained by adjusting the gm of the FET6 or 14 and the low level is obtained by adjusting the gm of the FET5 or 13 independently.

Inventors

• 👤 Hiroshi Koyada

Bibliographic Details