It has always been difficult to transport fast logic signals long distances over copper conductors. Coaxial or twisted-pair transmission lines introduce attenuation, dispersion, ground loops, and provide an entrance point for external electrical noise. The result can be jitter, pulse width distortion, and ultimately logic errors.
The J720 is a compact signal-powered electrical-to-optical converter.
When used with a J730, the combination can transport logic level or critical timing triggers over kilometer distances in high EMI environments with link jitter typically below 10 picoseconds RMS. The J730 provides a digital logic output with risetime below 750 picoseconds, and a fast analog (180 MHz bandwidth) output is also provided for monitoring link integrity.
The J720 is compatible with the Highland model P400 Digital Delay/Pulse Generator and the company's VME-packaged electrical/optical converter products.
The J720 is also an excellent driver for the T760 dual-channel, 100-volt optical-to-electrical converter.
| FUNCTION | Single-channel logic-level electrical-to-optical converter |
| INPUT | 0 to +5 volt maximum allowed input Input impedance 50Ω nominal (DC coupled) BNC female connector |
| PROPAGATION DELAY | 1 ns, nominal (50% electrical to 50% optical levels) |
| OUTPUT | 1 mW nominal optical fiber power when driven with 5 volt, 50Ω source 850 nm or 1310 nm nominal wavelength versions ST female multimode connector or FC female singlemode/multimode connector |
| BANDWIDTH | DC to 180 MHz |
| RISETIME | < 250 ps (driven by P400) |
| JITTER | < 12 ps RMS (J720 + J730 combination) |
| OPERATING TEMPERATURE | 0 to 60°C; extended MIL/COTS ranges available |
| CALIBRATION INTERVAL | One year |
| CONNECTORS | BNC electrical input jack ST or FC optical output receptacle |
| PACKAGING | Aluminum tube enclosure 0.5" (12.7 mm) diameter x 3.25" (82.6 mm) max length |
J720-1: 850 nm single-channel compact electrical-to-fiberoptic converter with ST connectorization
J720-3: 1310 nm single-channel compact electrical-to-fiberoptic converter with ST connectorization
J720-11: 850 nm single-channel compact electrical-to-fiberoptic converter with FC connectorization
J720-13: 1310 nm single-channel compact electrical-to-fiberoptic converter with FC connectorization