VCXO Methodology to Achieve wide Frequency Pulling in Low Profile for Space Applications

Abstract

Frequency Pulling is one of the critical parameters of Voltage-controlled Crystal oscillators (VCXO), it is always a challenge to achieve very high pulling in quartz crystal oscillators due to its self-limitation of quartz crystal motional parameters and oscillator circuit topology. This paper describes the selection of circuit topology, crystal parameters, critical electronic components, and VCXO packaging to achieve the required pulling in a low-profile package. Pulling of min ±375 ppm has been achieved over a control voltage range of 0V to 5V with the design optimization. In addition, the performance of VCXOs over the complete operating temperature range of -30°C to 60°C will be discussed. Simulation tools were used for parameter optimization to achieve the required specification.