Patent ID: 6104254
Filing Date: 2000-08-15
Classification: H03K

Abstract:
A 1 Ghz CMOS voltage controlled oscillator (VCO) circuit, comprising:a replica circuit including no more than two transistors to limit capacitance;a first VCO cell coupled to said replica circuit;a second VCO cell coupled to said first VCO cell and said replica circuits;a VCO output for transmitting a VCO output signal;a first current source coupled to said first VCO cell to transmit a first current from said power supply to said first VCO cell;a second current source coupled to said second VCO cell to transmit a second current from said power supply to said second VCO cell; andsaid first VCO cell and said second VCO cell having respective first and second load transistors coupled to said replica circuit said replica circuit including a single load transistor and implemented to replicate a current and voltage characteristic of said first VCO cell, such that said CMOS voltage controlled oscillator circuit reliably oscillates at a frequency of at least 1 GHz.