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

Volume

37

Issue

6

fYear

2002

fDate

6/1/2002 12:00:00 AM

Firstpage

702

Lastpage

710

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 f_osc = 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;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.2002.1004574

Filename

1004574