V – I converter‐based voltage‐controlled oscillator with improved linear gain characteristic

A voltage–current ( V–I ) converter‐based voltage‐controlled oscillator (VCO) is adapted to generate multiple‐phase clocks for clock and data recovery for a display driver IC. The proposed V–I converter changed the second‐order current equation of the VCO to a first‐order current equation of the VCO, to achieve a wide operating frequency range, a linear gain ( K VCO ) within a wide control voltage, low power, and a small area without any extra circuits, such as a low‐to‐full amplifier. Owing to the V–I converter, K VCO is changed from 8.43 to 2.05 MHz/mV with a wider V ctrl range, and its tuning range is changed from 114 to 452 MHz with a linear gain characteristic. The proposed VCO is implemented in a 1P6M 1.8 V technology and is suitable for the phase‐locked loop used in flat‐panel display interfaces that operate from 0.3 to 2 Gbit/s.