Electronics Sourcing asked AEL Crystals operations director, Shaun Mellors, to explore trends in frequency control products. Read on to discover his thoughts
Technology in frequency control products (FCPs) is constantly changing. Factors effecting current device development include: the usual push to reduce package size; tighter specification; higher frequency demands; lower power/voltage; and pressure to reduce cost and lead-time.
Regarding package size, the standard SMD package for high technology applications has moved from 7 by 5mm to 5 by3.2mm, with packages also now available in production volume at 4 by 2.5mm, 3 by 2.5mm and 2 by 2.5mm. Costs for smaller devices are also starting to fall. In addition, 1.6 by 1.2mm parts will soon be in commence production. However, for cost sensitive applications the HC49S SMD and 7 by 5mm parts are still popular due, predominantly, to their lower cost.
Looking at specifications, both crystal and oscillator devices are seeing changes. While the standard microprocessor part is still in demand, there are many silicon devices that require more detailed specification FCPs for consistent operation. Many devices exhibit low power start-up making ESR and DLD specifications more critical. Also, increasing RF applications require tighter stability, aging and pulling requirements.
For oscillator products in particular, phase noise, power consumption and overall stability are often much tighter. Increasingly, there is a requirement for greater application flexibility. For example, the AEL LTCC range of TCXO/VCTCXO parts offer 1.8V battery operation, while also offering excellent phase noise, power consumption and stability combinations.
Clock oscillators with stabilities down to +/-5ppm are in development and TCXO devices to +/-0.5ppm are available today.
Regarding cost vs performance, smaller packages, tighter specifications and higher frequencies put pressure on pricing. However, many FCPs applications are extremely cost sensitive. The main problem is over specification. This situation demonstrates the role of specialised vendors who can help manufacturers specify the most cost effective part.
Once designs reach production, another set of cost variables and requirements emerge: predominantly due to outsourcing production. To combat such problems, AEL Crystals offers full logistical support including buffer stock, KanBan, sample support, direct shipping and localised warehousing in Europe and South East Asia.
Higher stability TCXO and VCTCXO devices continue to push into areas previously only supported by OCXO products. Also, applications using crystal resonators for cost are now looking to much lower cost TCXO/VCTCXO devices to improve performance without sacrificing end product competitiveness. This trend will continue with increased stability and aging characteristics, plus higher frequency availabil