A 0.5-to-400MHz Programmable BAW Oscillator with Fractional Output Divider Achieving 4ppm Frequency Stability over Temperature and <95fs Jitter

Bulk-Acoustic-Wave (BAW)-technology-based oscillators have recently been introduced that combine a BAW resonator die with a CMOS circuit die containing oscillator and temperature compensation circuits [1]. In this work, we leverage the BAW technology to create a user programmable oscillator with attractive characteristics such as long-term reliability, miniaturization and low cost. Unlike low-frequency crystal/MEMS-based programmable resonators that require a fractional PLL to generate higher output frequencies [4–6], BAW resonators, due to a high resonant frequency (~2.5GHz), allow programmability by making use of a Fractional Output Divider (FOD), as developed in this work.