A Design Method of Wide Tuning Range DCO by Using Aluminium Pad Metals for Zero Revision

Abstract

This paper presents a design method of digitally controlled oscillator (DCO) to increase the accuracy for expectations in terms of frequency range and frequency step. Parasitic inductances by routing lines make nonlinear frequency steps and unexpected frequency range. Aluminum (AI) pad metals with very large width are employed as a pattern for eliminating parasitic inductance (PEPI). Since considerably very small inductors are connected in parallel between routing metals, added parasitic inductances become negligible. Frequency range and step of designed DCO can be exactly expected by using PEPI. Proposed design method is helpful to meet tough specification with small margin in terms of frequency range.