Epson Toyocom Develops TCXO for High-Precision GPS Applications
Epson Toyocom Corporation (“Epson Toyocom”), the leader in crystal devices, has announced the development of a new frequency-stable TCXO (temperature-compensated crystal oscillator) with frequency stability high enough for demanding GPS applications. The new TG-5025BA oscillator is housed in a 2016-sized package, the world’s smallest package category (actual dimensions are 2.1 x 1.7mm). Commercial development is scheduled for February, 2009.
The market for GPS capability in mobile terminals has been expanding in recent years. In particular, the percentage of cell phones with built-in GPS functions is rising globally due to applications that allow their location to be pinpointed in the event of an emergency call. The expansion of the market for personal navigation devices (PND) and other navigation systems is also driving demand for frequency-stable TCXOs, which are essential for accurate positioning. Mobile GPS devices such as these will be packing more features in increasingly dense assemblies and this trend is expected to drive market demand for high-stability TCXOs, especially small units.
Epson Toyocom is already setting the pace in GPS market trends with the TG-5005CG, a TCXO equipped with a photo AT chip. However, while the TG-5005CG offers high stability (0.5 x 10-6) in a 2.5 x 2.0 mm package, the market is already looking toward even smaller sizes. Epson Toyocom is on target to meet the more stringent size requirements with the commercial development of the TG-5025BA, a 2016-class TCXO that offers outstanding frequency stability.
The TG-5025BA is equipped with a photo AT chip, a very small, crystal chip microfabricated using Epson Toyocom’s unique QMEMS*1 technology. In addition to minimal variability of characteristics, the new oscillator promises high reliability thanks to the use of internal wire bonding and Epson Toyocom’s original NPO (New Platform Oscillator) structure*2. In the NPO structure the crystal unit, encased in a ceramic package, is sealed together with an oscillation circuit in a molded plastic housing. This structure reduces the susceptibility of frequency to changes in ambient temperature. Epson Toyocom’s IC design technology brings additional advantages to the TG-5025BA, including precise temperature compensation, low power consumption since driving is performed at voltages as low as 1.68 V, and a wide output frequency range (13 to 52 MHz).
Epson Toyocom has successfully combined all the essential technologies for the development and manufacture of crystal devices: superior crystal chip processing, packaging and circuit design technologies. The result is a small, stable, GPS-ready TCXO. The TG-5025BA boasts a 36% smaller footprint and a 43% smaller cubic volume than its predecessor (2520 TCXO product).
Despite its size, however, it has a frequency-temperature coefficient (an indicator of frequency stability over a temperature range) of 0.5 x 10-6, a rating equivalent to that of a TCXO in a conventional package size. To top it all off, the TG-5025BA is stingy when it comes to power consumption, using some 30% less power than its predecessor.
Epson Toyocom plans to continue to beef up its line of ultra-miniature 2016 TCXO products and develop even smaller high-stability TCXOs to meet the burgeoning demand in the GPS market, where end-products sizes are shrinking as packaging densities increase.
Fig. 1 Size comparison between the current core product in a 3225 package (left) and the new product in a 2016 package (right)
1.World’s smallest class of package (2016 size = 2.1 x 1.7 mm), for a footprint 36% smaller and a cubic volume 46% smaller than its predecessor
2.Frequency stability on a par with that of its predecessor. Capable of supporting even GPS applications, with a frequency-temperature coefficient of 0.5 x 10-6 (-30° to +85°C)
3.Low-voltage driving, with a minimum voltage of 1.68 V. The low-power design cuts power consumption by approximately 30% compared its predecessor
4.A wide output frequency range of from 13 to 52 MHz
5.High reliability provided by the use of wire bonding