Title :
A Low Voltage All-Digital On-Chip Oscillator Using Relative Reference Modeling
Author :
Yu, Chien-Ying ; Yu, Jui-Yuan ; Lee, Chen-Yi
Author_Institution :
Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
This paper presents a low voltage on-chip oscillator which can compensate process, voltage, and temperature (PVT) variation in an all-digital manner. The relative reference modeling applies a pair of ring oscillators as relative references and estimates period of the internal ring oscillator. The period estimation is parameterized by a second-order polynomial. Accordingly, the oscillator compensates frequency variations in a frequency division fashion. A 1-20 MHz adjustable oscillator is implemented in a 90-nm CMOS technology with 0.04 mm area. The fabricated chips are robust to variations of supply voltage from 0.9 to 1.1 V and temperature range from 0°C to 75°C. The low supply voltage and the small area make it suitable for low-cost and low-power systems.
Keywords :
CMOS digital integrated circuits; estimation theory; integrated circuit modelling; low-power electronics; oscillators; parameter estimation; polynomials; CMOS technology; PVT variation; frequency 1 MHz to 20 MHz; frequency division variation; internal ring oscillator; low voltage all-digital on-chip oscillator; low-power system; parameterized estimation; process-voltage-temperature variation; relative reference modeling; second-order polynomial; size 90 nm; supply voltage; temperature 0 degC to 75 degC; voltage 0.9 V to 1.1 V; Accuracy; Delay; Frequency measurement; Logic gates; Ring oscillators; System-on-a-chip; Digitally controlled oscillator (DCO); frequency compensation; low voltage; oscillators; process, voltage, and temperature (PVT) variations;
Journal_Title :
Very Large Scale Integration (VLSI) Systems, IEEE Transactions on
DOI :
10.1109/TVLSI.2011.2160301
