Clock ICs replace VCOs

摘要

Replacing larger, expensive, high-frequency VCOs, the AD9552 frequency upconverter uses either a single-ended low-frequency reference signal or a crystal reference to establish a higher output frequency. The upconverter provides a jitter of under 0.5 ps operating with input frequencies in the range of 50 kHz to 80 MHz.rnThe device can generate almost any desired output frequency up to 900 MHz, consumes less than 400 mW, has a three-wire SPI interface, and requires only a 12-nF external capacitor to complete the PLL's loop filter.