Quartz crystal in GT cut supports lower MHz frequencies
The crystal measures 1.6mmx1.2mm. Its width-extensional mode allows a package design unconstrained by blank size, enabling significantly smaller and lower-profile units operating at lower MHz frequencies.
The equivalent circuit constants of GT-cut quartz crystal units are comparable to those of AT-cut units. The devices are very stable to ±3ppm in the range of -20°C to 70°C, and ±5ppm in the range of -40°C to 85°C. They minimise vibration loss and ensure stable oscillation, even when driven at 5μW or less. These characteristics are difficult to achieve with traditional AT-cut quartz crystal units, claimed the manufacturer.
Compared to traditional AT-cut, GT-cut units achieve starting oscillation time approximately twice as fast, 550μs (compared to 12MHz FCX-05 in the same oscillation circuit and at the same frequency). GT-cut crystals are air-sealed with metal lids welded onto a ceramic package using a proprietary ebeam sealing technique.
- Julien Happich
EE Times Europe