Cmos ring oscillator

Abstract

Abstract PURPOSE:To improve the temperature characteristics, by providing a resistor made of polysilicon having a negative temperature coefficient, in a resistor train determining the frequency. CONSTITUTION:The oscillation frequency of a ring oscillator is determined with the time constant consisting of a resistor and a capacitor provided between gates. Since conventional resistors are of diffusion type having a positive temperature coefficient, a part of resistor R301 is formed with polysilicon having a negative temperature coefficient to improve the temperature characteristics of the entire oscillator. Polysilicon resistors are manufactured by controlling a resistance value and the temperature characteristics with ion implanting so that the desired characteristics can be obtained. As a result, the temperature characteristics of the ring oscillator on a CMOS integrated circuit can be improved.

Inventors

• 👤 Shigeru Komine
• 👤 Yasuhiko Nishikubo

Bibliographic Details