Date: Nov 26, 2013 Author: R Coin Johnson Source: EE Times (
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R. Colin Johnson
PORTLAND, Ore. — Sand 9 Inc. unveiled the TM651, the world's first high-precision temperature compensated MEMS oscillator (TCMO) to meet the noise and stability demands of communication, industrial and military applications. It is the first MEMS oscillator to challenge high-precision temperature compensated crystal oscillators (TCXOs).
According to Sand 9, its TCMO oscillators exceed the performance of quartz-based TCXO oscillators in activity dip suppression, electromagnetic interference, and immunity to vibration. The company says these features make them particularly advantageous to communications infrastructure applications, including cellular base stations, datacenter switches, Ethernet links, and point-to-point radios where packet loss is unacceptable.
"The TM651 is proving particularly popular with cellular infrastructure equipment makers, which today build vibration immunity into the mounts for their base stations because quartz crystals are sensitive to vibration," Vince Graziani, chief executive officer at Sand 9, told us. "But our TCMO technology is virtually immune to vibrations, eliminating the need for special mounts."
Sand 9 also says its piezoelectric design gives it 100 times better mechanical coupling than the traditional electrostatic coupling of conventional MEMS devices. This results in a higher signal-to-noise ratio.
The TM651 combines a 125MHz piezo-electric MEMS resonator with an ASIC that contains the temperature compensation circuitry. It features differential outputs, jitter of less than 300 femtosecond, and a stability of plus or minus 5 parts per million over a temperature range of -40°C to 85°C.
The TM651 is available in a chip-scale package that can be overmolded inside the package of the chip for which it is supplying the timing signals, or in a traditional land-grid array can that is pin-compatible with quartz crystal oscillators.
