Epson Introduces New Any-Rate Programmable VCXOs
Epson’s VG7050EAN and VG7050ECN “Any-Rate” programmable VCXOs enable optical transmission equipment to support multiple protocols and line rates with a single oscillator. Earlier equipment used either a single fixed-frequency oscillator which had to be swapped out to change frequencies or multiple fixed-frequency oscillators which increased board space and cost.
Seeking to solve these problems, Epson created the new low-jitter low-power programmable VCXOs by combining a highly accurate and stable high-frequency fundamental (HFF) crystal that can oscillate at a fundamental frequency over 100 MHz with a low-jitter fractional-n PLL IC. Epson’s HFF crystal technology is more reliable than 3rd overtone crystals and achieves better phase noise and jitter than low-frequency fundamental crystals. As a result, Epson’s VG7050EAN and VG7050ECN achieve the world’s lowest jitter (0.27 ps) of any programmable VCXO at both SONET (622.08 MHz) and Ethernet (156.25 MHz) frequencies.
Both the VG7050EAN and VG7050ECN are factory programmed for frequency and absolute pull range (APR). The default settings can be overwritten using an I2C bus so users can program any output frequency and APR they require. To simplify multi-protocol designs, the VG7050ECN allows four frequencies to be pin-selectable.
Moving forward, Epson will leverage its unique technological strengths in crystal microfabrication and semiconductors to provide customers with device solutions that are safe, easy to use, and dependable.
- Low noise and low jitter: These products use an HFF crystal unit that is capable of oscillating at a fundamental frequency of 100 MHz or more. The HFF crystal unit is combined with Epson’s own fractional–N PLL IC to achieve low jitter, optimize the frequency of the crystal unit, and control integer-boundary spurs.
- Low current consumption: The maximum current consumption is 90 mA (including LVPECL terminal load drive current). Epson’s VG7050EAN and VG7050ECN are the industry’s lowest power devices in this class.
- Frequency programmable: The output frequency can be set to any frequency between 50 MHz and 800 MHz.
- APR programmable: Users can select the desired absolute pull range (APR) from among 12 steps within the range of 0 to ±180 × 10-6.
- Product name: VG7050EAN, VG7050ECN
- Output frequency: 50 MHz to 800 MHz
- Supply voltage: 2.5 V ±5% / 3.3 V ±10%
- Operating temperature range: -40°C to +85°C
- Frequency tolerance: ±50×10-6
- Current consumption during operation: 70 mA, typ. (at 622.08 MHz output); 90 mA, max. (when driven at 3.3 V)
- Phase jitter: 0.27 ps, typ. (at 156.25 or 622.08 MHz output)
- External dimensions: 7.0 × 5.0 × 1.5 mm, typ. (7050 size)
- Output: LVPECL
- Absolute pull range (APR) 0 to ±180 × 10-6, Control voltage: 0.25 V to 2.25 V (when driven at 2.5 V), 0.3 V to 3.0 V (when driven at 3.3 V)
- Frequency setting when power is supplied: 1 type, Use special pin to select 1 setting from among 4 types