NMOS Inverter With Stabilized Delay for Ring Oscillators
Original Publication Date: 1987-Jun-01
Included in the Prior Art Database: 2005-Feb-01
This article describes an NMOS ring oscillator (inverter stage) whose cycle time (delay) is less sensitive to process parameter and power supply variations by a factor of two over previous designs, a ring oscillator (inverter stage) with reduced sensitivity to external loads, and an inverter stage whose delay is primarily controlled by a single-enhancement device. Ring oscillators are used for timing chains, substrate bias generators, etc. By having a reduction in cycle time variations due to process parameters and power supply variations, the applications of ring oscillators can be extended. Ring oscillators usually consist of an odd number, greater than one, of inverters forming a loop or ring.