Trend Networks TIA525I-ST – InGaAs O/E Converter (DC to 125 MHz) with ST Connection

• DC to 125 MHz bandwith
• InGaAs detector
• ST fiber optic interface
• Spectral response: 850 – 1700 nm
• Low Noise – 3.0 pW/root-Hz

The TIA-525 Optical to Electrical Converter is a convenient battery-operated detector/amplifier combination that mounts directly on the input of an oscilloscope, digitizer, or other readout device. With a band width of DC to 125 MHz, it accurately provides an electrical replica of the optical signal presented to it. It is fully capable of driving a 50 ohm cable terminated in its characteristic load.

Two basic models of the unit exist; the TIA-525S, containing a silicon detector for use in the spectral region between 400 and 1000 nm, and the TIA-525 I which contains an IndiumGallium-Arsenide detector and is responsive in the 900 to 1700 nm spectral region. Both units are equipped with an ST fiber optic connector. Custom versions are also available with un-connectorized detectors for free-space beams.

The TIA-525 has selectable transimpedances of 1.4 KΩ and 14 KΩ plus a post amplifier with selectable gains of 1 or 10. Thus the overall responsivity ranges from approximately 1, 000 V/W to 100, 000 V/W at the peak of the detector response curve. Interstage coupling may be switched from DC to AC to avoid saturation of the second stage in those cases where the signal of interest is combined with a relatively large DC optical component

Each unit is powered by a self-contained 9 V lithium battery or a universal wall mount power supply. Battery operation eliminates ground loops and the undesirable effects of conducted radiation that may be present on local power lines.

Series Comparison

Each unit comes equipped with a 9 V Lithium battery that provides power to the unit for approximately 30 hours of operation. It is recommended that the battery be replaced whenever the output signal becomes clipped at 1 volt or less. When replacing the battery, a Lithium unit should be used. Conventional 9 V alkaline batteries may be used if so desired but the useful life will only be about 25% (8 hours) of that of the much higher capacity Lithium types. TREND Networks can supply these batteries if desired. Replacement of the battery may be accomplished by removing the four 2-56 Philips flat head screws that retain the bottom cover of the TIA-525. DO NOT attempt to remove the top cover. Take care to replace all screws tightly. This will provide optimum shielding of the unit from ambient radio frequency noise or interference.

The TIA-525 is also supplied with a universal power supply that operates from 90 to 240 VAC, 50-60 Hz. Each unit is equipped with four interchangeable power plugs that equip the unit for use in North America, Europe, the UK or Australia. Plugging the power supply into the unit disconnects the internal battery.