Epson intros VCXOs for optical networks and mobile base station equipment

Epson Electronics America, Inc. (EEA) says it has begun shipping samples of the VG-4513CB series of voltage-controlled crystal oscillators (VCXO). Designed for use in optical transport networks and LTE (Long Term Evolution) base stations, the VG-4513CB uses a high-frequency fundamental crystal to achieve output frequencies up to 500 MHz with no spurs and very low phase noise and low jitter. The VG-4513CB also comes in a package that is 87% smaller than existing VCXOs, and has excellent vibration sensitivity, the company claims.

Epson says the VG-4513CB is the industry’s first VCXO to deliver output frequencies up to 500 MHz without using a phase-locked loop (PLL) or frequency multiplier. Instead the device uses a high-frequency fundamental-mode AT-cut crystal, which Epson claims results in better reliability, lower power, and lower phase noise than existing 500-MHz VCXO products. This approach enables the VG-4513CB to attain jitter of 50 fs RMS at 491.52 MHz. Unlike PLLs and frequency multipliers, Epson says the fundamental technology does not generate spurs.

The high-frequency fundamental-mode crystal is fabricated using Epson’s QMEMS technology. QMEMS combines the superior material characteristics of quartz with micro-electrical mechanical system (MEMS) fabrication techniques. In addition to allowing reliable fundamental-mode oscillation, QMEMS enables size reduction of the VCXO and improves vibration sensitivity.

Epson’s VG-4513CB is delivered in a 5.0x3.2x1.3-mm package, which makes its footprint 87% smaller than traditional 14x9-mm VCXO products. This size reduction enables very dense designs such as multi-channel optical networking equipment and multi-channel multiple input multiple output (MIMO) LTE base stations.

Epson also claims that the QMEMS technology enables Epson to improve vibration resistance three-fold over previous products. At 0.6 ppb/g, Epson’s VG-4513CB provides a stable frequency reference for base stations that must be installed in challenging environments, such as near railroad tracks.

“With their compact design, high precision, and high stability, Epson’s new products will contribute to the success of LTE,” said Masayuki Morozumi, executive vice-president and chief operating officer of Epson's microdevices operations division.

Epson's VG-4513CB is available in three pull ranges (the range over which it can lock onto the signal): ±30×10^-6, ±50×10^-6, and ±100×10^-6.

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