Title :
A coupled sawtooth oscillator combining low jitter with high control linearity
Author :
Gierkink, Sander L J ; van Tuij, E.
Author_Institution :
MESA Res. Inst., Twente Univ., Enschede, Netherlands
fDate :
6/1/2002 12:00:00 AM
Abstract :
A new type of relaxation oscillator is presented that combines excellent control linearity with low timing jitter. By using an alternative for the Schmitt trigger, the jitter caused by threshold level noise can be significantly reduced compared to a conventional relaxation oscillator, under equal conditions of control linearity. Circuits realized in a 0.8-μm CMOS process show a typical measured distortion in the control characteristic of HD2 = -67 dB and HD3 = -90 dB (Δf = 500 KHz), without using any feedback linearization techniques. The measured phase noise is -102 dBc/Hz at 10-kHz offset at fosc = 1.5 MHz (65-ppm rms jitter) for a total supply current of 360 μA
Keywords :
CMOS analogue integrated circuits; charge injection; coupled circuits; electric current control; phase noise; relaxation oscillators; timing jitter; voltage-controlled oscillators; 1.5 MHz; 360 muA; CMOS process; K-mismatch; VCO; capacitor voltage swing; charge injection; coupled sawtooth oscillator; current mirror transistors; current-controlled oscillator principle; high control linearity; low timing jitter; phase noise; relaxation oscillator; threshold level noise; threshold-voltage mismatch; Circuit noise; Distortion measurement; Feedback circuits; High definition video; Linearity; Noise level; Noise reduction; Oscillators; Timing jitter; Trigger circuits;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2002.1004574
