IQD enhances real-time clock performance for process control and portable devices
Posted: 15th September 2008
A new range of "watch crystal" oscillators offering a four-fold improvement in stability over previous-generation devices is introduced by IQD Frequency Products. Providing output at the standard watch crystal frequency of 32.768 kHz - divisible to precisely the 1Hz requirement of a real-time clock - the CFPS-107/108/109 oscillator series offers stability down to 20ppm over its operating temperature range in a miniature 2.6 x 2.1 mm ceramic SMD package.
IQD has improved on the 80ppm stability typically offered by watch crystal oscillators by using an AT-cut rather than a GT-cut quartz crystal resonator. AT-cut crystals provide an inherently more stable frequency output, but at a higher frequency. The CFPS-107/108/109 uses a divider to bring the high internal signal frequency down to the required 32.768 kHz.
The CFPS-107/108/109 is particularly well suited to process control applications, being available with a -40° to +85°C industrial operating temperature range as well as the standard 0 to +70°C. It also offers a high level of shock and vibration resistance, with qualification to Mil-Std-883F.
For use in lightweight portable devices in both industrial and consumer applications, the low-power CFPS-107 operates from a 1.8V supply and so is capable of running from a single battery. Supply voltages of 2.5V (CFPS-108) and 3.3V (CFPS-109) are also available.
All devices offer CMOS output and tristate operation. They can be supplied in either bulk pack or tape-and-reel formats.