Mainstream crystal oscillators

- by Macrobizes

Lead, DIP and SMD types constitute the selection in China, with the last two forming the mainstream supply.

Based on the general circuit, the range includes SPXO, TCXO, VCXO, FCXO and OCXO versions. As the first has no temperature compensation or control feature, it is mostly used as reference oscillators in communication equipment, measuring instruments and controllers. In computers, office automation equipment and information terminal devices, SPXO units function as clock oscillators.

TCXO kinds work as reference oscillators as well in mobile phones, GPS devices, land mobile radio systems, and microwave and satellite communication systems. They are also adopted in measuring instruments such as frequency counters and synthesizers.

VCXO finds application mainly in PLL-based synchronization and demodulation in transmitters and switchboards. FCXO suits frequency conversion in transmission devices and frequency synchronization. OCXO is utilized as reference oscillator for communication equipment, including mobile base stations, and electronic measuring instruments such as frequency counters and spectrum analyzers.

By output, there are sine wave, clipped sine wave, transistor-transistor logic, CMOS, positive emitter coupled and low-voltage differential signaling oscillators.

Products come in 1.8, 2.5, 2.8, 3.3, 5 and 12V models. These have output frequency ranging from 0.5 to 200MHz.

The key materials include quartz blank, substrate, housing, ceramic and silver. Makers usually source them locally.

Although input costs remain flat, expenditure for labor and the yuan value continue to climb. Suppliers, however, are keeping prices steady in the months ahead to stay competitive.