VOLTAGE CONTROLLED OSCILLATOR

摘要

The invention relates to a voltage controlled oscillator (VCO), for use in a phase locked loop for clock multiplication, for example in recovery of data pulses from a data stream input comprising digital data with unknown phase. According to the invention, the VCO comprises a plurality of VCO stages, each stage being implemented as a differential amplifier. The amplifier load is formed of two cross-coupled gate devices (M5 and M6) and of two gate devices (M8 and M9) which are connected as diodes. The differential input is applied to a source coupled input pair (M2 and M3) as well as to two pull-down gate devices (M4 and M7).