High stability oscillator in small package for optical module

The pandemic has ushered in the 'new normal' of remote-work and remote-study, leading to an accelerated increase in the data traffic. Network infrastructure is getting further important to sustain this trend, and there has been a significant demand for optical modules being installed inside / intra data centers. Epson has been supporting this with crystal oscillator SG2520 series, which provides low jitter and high stability in a small form factor, 2.5 x 2.0 mm. The optical modules are moving towards higher date rates like 400G, 800G, and beyond. These modules require even smaller crystal oscillator to accommodate the larger DSPs. Epson offers further smaller form factor crystal oscillator in 2.0 x 1.6 mm with the identical performance to current one in 2.5 x 2.0 mm, such as low jitter and high stability. With this new product, Epson enables more flexible layouts in customer's design, better performance of the equipment. These changes from Epson are in line with our commitment to benefit the society with technological advances.

Link to SG2016 series product pages
SG2016EGN SG2016VGN SG2016EHN SG2016VHN

sg2016xgn
(2.0 x 1.6 x 0.63 mm)

networking

Requirements from optical module market

(1) PAM4

Optical modulation format is changing from NRZ to PAM4 because of high-speed and wide-band network. PAM4 has twice the bandwidth compared to NRZ

sg2016xgn

PAM4 requires low jitter because signal level is smaller than NRZ and it is difficult to ensure the signal detection accuracy. About 100 fs is required for acceptable BER.Small size and low current consumption are required for downsized optical module. Frequency tolerance ±50 x 10-6 is sufficient.

(2) 400ZR

400ZR / 800ZR are coherent optical technology for 400/800 Gbps high speed communication. Coherent optics modulates data allowing for higher data rates. 800ZR is now worked to define.

sg2016xgn

The DAC/ADC inside the DSP needs a very low jitter sampling clock and in the GHz band to process 400/800 G signals. In order to generate this clock, a high frequency, low jitter and high stability SPXO is needed. Furthermore, lower current consumption and small size are required as well. Epson SPXOs offer all.

Epson provides solution by SG2016 series

SG2016 series: High stability, low jitter crystal oscillator, Downsized to 64 %(area), 54 %(volume) from SG2520

Combined HFF (*1) crystal chip and Epson's in-house IC, SG2016 series provides high frequency, high stability, and low jitter. With these features, SG2016 series best fits to 800G+ optical module.
(*1) HFF = High Frequency Fundamental
- PAM4: SG2016EGN/VGN best fits, with low jitter, low current consumption, small size
- 400ZR: SG2016EHN/VHN best fits, with high stability ±20 x 10-6 , low jitter, low current consumption, small size

Applications

  • Optical module
    (for Network equipment, Router, Switch, etc.)
  • Data center
  • Test and Measurement Equipment, Factory Automation
  • High Speed Converters like ADC and DAC

networking

Feature of SG2016 series

1. Small form factor in 2.0 x 1.6 mm

Downsized from SG2520 series, 64 % in area, 54 % in volume

small size

Video: Introduction of SG2016 series

2. High frequency and low jitter achieved by Epson’s unique technologies

The fundamental oscillation by HFF crystal chip helps high frequency and low phase jitter characteristics.

HFF crystal chip

A high-frequency fundamental was enabled without compromising crystal chip strength by photolithographically processing only the oscillating portion of the chip so as to form an extremely thin inverted-mesa structure with a thickness of only several microns.

Video: Advantage of Differential Output with HFF

small size

Low phase jitter / phase noise

HFF crystal chip and inhouse low noise IC for SPXO achieves low phase jitter / phase noise characteristics.
Phase jitter: 19 fs
  - LVDS, fo = 391.77 MHz
  - Offset Frequency: 12 kHz to 20 MHz
  - Supply voltage = 3.3 V

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3. Temperature compensation provides high stability even at high temperature

±20-6 at +105 ℃ including 10 years aging by Epson’s in-house IC

small size

Specifications

Model No. SG2016EGN SG2016EHN SG2016VGN SG2016VHN
Output type LV-PECL LVDS
Output frequency range 25 MHz to 500 MHz
Supply voltage 2.5 V ± 5 %
3.3 V ± 5 %
1.8 V ± 5 %
2.5 V ± 5 %
3.3 V ± 5 %
Operating temperature -40 ℃ to +85 ℃、 -40 ℃ to +105 ℃
Frequency tolerance ± 25 x 10-6
± 50 x 10-6
± 20 x 10-6 ± 25 x 10-6
± 50 x 10-6
± 20 x 10-6
Current consumption 60 mA Max. 28 mA Max.
Phase jitter (12 kHz to 20 MHz) 70 fs Max. (output frequency: 156.25 MHz)
50 fs Max. (output frequency: 491.52 MHz)
60 fs Max. (output frequency: 156.25 MHz)
50 fs Max. (output frequency: 491.52 MHz)
Dimensions 2.0 x 1.6 x 0.63 mm

Dimensions, Block diagram, Pin map

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Changes from the existing products

Compared to the existing products (SG3225/5032/7050 Series), SG2016/2520 series have advantages in the followings
(1) Smaller size
(2) Tighter frequency stability
(3) Lower phase noise and phase jitter

1 Smaller size

2 Tighter frequency stability

3 Lower phase noise and phase jitter

Both have a fundamental mode crystal (HFF crystal) that achieves excellent phase jitter and phase noise characteristic. New products have better noise floor and phase jitter, which are the important characteristics for network system.

vs existing products

Item SG2016EGN / SG2016EHN
SG2016VGN / SG2016VHN
SG2520EGN / SG2520EHN
SG2520VGN / SG2520VHN
SG3225/5032/7050EEN
SG3225/5032/7050VEN
Frequency 25 MHz to 500 MHz 25 MHz to 500 MHz 25 MHz to 500 MHz
Technology Fundamental Fundamental Fundamental
Size 2.0 x 1.6 x 0.63t mm 2.5 x 2.0 x 0.74t mm SG3225*EN: 3.2 x 2.5 x 1.05t mm
SG5032*EN: 5.0 x 3.2 x 1.3t mm
SG7050*EN: 7.0 x 5.0 x 1.5t mm
Operating
Temperature
-40 ℃ to +105 ℃ -40 ℃ to +105 ℃ -40 ℃ to +105 ℃
Frequency
Tolerance
±20 x 10-6
(SG2016EHN / SG2016VHN)
±25 x 10-6,±50 x 10-6
(SG2016EGN / SG2016VGN)
±20 x 10-6
(SG2520EHN / SG2520VHN)
±25 x 10-6,±50 x 10-6
(SG2520EGN / SG2520VGN)
±50 x 10-6 (≦200 MHz)
±100 x 10-6 (>200 MHz)
Phase Jitter
(3.3 V,
391.77 MHz,
LVDS)
19 fs Typ. / 50 fs Max. 19 fs Typ. / 50 fs Max. 37 fs Typ. / 60 fs Max.
Current
Consumption
60 mA Max.
(SG2016EGN / SG2016EHN)
28 mA Max.
(SG2016VGN / SG2016VHN)
60 mA Max.
(SG2520EGN / SG2520EHN)
28 mA Max.
(SG2520VGN / SG2520VHN)
60 mA Max.
(SG3225/5032/7050EEN)
25 mA Max.
(SG3225/5032/7050VEN)
Output LV-PECL / LVDS LV-PECL / LVDS LV-PECL / LVDS

Feature of SG2016 series
  - Downsizing (our smallest differential XO)
  - narrow frequency tolerance (SG2016EHN / SG2016VHN: ±20 x 10-6)

Link to SG2016 series product pages
SG2016EGN SG2016VGN SG2016EHN SG2016VHN

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