A regulated supply tunning voltage-controlled oscillator with built-in test and calibration

This paper presents a regulated supply tuning voltage-controlled oscillator with built-in test and calibration. A low-dropout regulator with an integrated low-pass filter operates as a frequency-tuning element with inherent noise suppression. Frequency calibration employs a bias current tuning in three frequency ranges for adjusting an oscillation frequency shift caused by parametric faults. Built-in voltage and current sensors facilitates on-chip accessibility and testability for catastrophic faults. Circuit implementation using 0.18-μm CMOS technology demonstrates low jitter performance of less than 14.32 ps at the oscillation frequency of 200 MHz. High and low frequency ranges can be calibrated with the offset frequencies of 22 MHz and 20 MHz, respectively, through two-bit control signals. Tests for potential shorts and opens show total fault coverage of 83.68%.