THE RELIABILITY COMPENSATION METHOD OF VOLTAGE CONTROLLED OSCILLATORS

Abstract

Voltage-controlled oscillators are essential components in a wide range of analog and mixed-signal systems such as phase-locked loops, clock-to-data recovery circuits, high speed transceivers, etc. The scope of such oscillators is generation of high-speed sinusoidal or digital periodic signals whose frequency directly depends on the applied DC control voltage. Nowadays, integrated circuits in which the above-mentioned systems take part are widely used in different spheres of industry and human life. Based on the aspect of their usage, different reliability requirements are considered. For instance, in mobile applications reliability requirements are more relaxed than in automotive, military or aerospace applications where even 1% of deviation of system parameters may result in disastrous consequences. In parallel, reliability parameters strongly depend on the manufacturing process consistency. For low accuracy technology nodes, the variations can reach several hundred percent, while in high accuracy manufacturing technologies, this number can be reduced up to a few percent. There are several factors on which the reliability of integrated circuits depends on. Such are electromigration, ageing, IR drop on supply rails, etc.

In this paper, the ageing impact reduction method on the reliability of voltage-controlled oscillators is proposed. Based on the proposed schematic design and HSPICE simulation results, the output frequency variation of voltage-controlled oscillator is reduced from 15% to 3%.