Extremely high-frequency crystal oscillators provide margining and low-jitter performance for demanding communication applications
(Technology News, 09 May 2008 )
Maxim Integrated Products has introduced the DS4M-XO series of crystal oscillators, which supports frequency operation from 100MHz to 300MHz and provides frequency margining in a 5.0mm x 3.2mm package. Said to be the industry's first crystal oscillators to provide frequency margining at levels of ±5%, the DS4M-XO series facilitates frequency-margin testing in production environments through simple logic control, thereby eliminating the need for signal generators and nonstandard oscillator frequencies. The ease of use, small size, and high performance of these crystal oscillators make them ideal for use in space-constrained Ethernet, InfiniBand, PCI, and PCI Express II applications.
Fifty-five percent smaller than competitive solutions, the DS4M-XO devices are available in a 5mm x 3.2mm ceramic package with an integrated crystal. These XOs are manufactured using fundamental AT-cut crystal technology with no overtone, and they integrate a low-noise, PLL-based oscillator designed using Maxim's proprietary SiGe process. This design ensures jitter performance of less than 1psRMS (12kHz to 20MHz) over the -40 degrees Celsius to +85 degrees Celsius extended temperature range.
These crystal oscillators are highly competitive against both SAW-based and third-overtone crystal oscillator designs. The DS4M-XO devices provide exceptional long-term aging characteristics (< ±7ppm), good stability over temperature (< ±50ppm), low phase-jitter performance (< 1psRMS), and smaller packaging (5mm x 3.2mm versus 5mm x 7mm). Moreover, these XOs provide frequency margining, which is not currently provided by SAW-based or third-overtone oscillator designs.
Standard frequencies for the DS4M-XO series of margining XOs include 125MHz (DS4M125), 133MHz (DS4M133), and 200MHz (DS4M200). For frequencies not listed above, customers should contact the factory for availability and lead-times.
