
Introduction
The LTX-551X Electrical to Optical and Optical to Electrical Converter system comprise a convenient
product that is intended to transmit analog and digital information to a remote location via fiber
optic cable. Its primarily designed to be used in those situations where the signal of interest has a
high common mode voltage with respect to the measurement equipment. Such situations arise in
plasma physics experiments, power transmission equipment, and high power laser systems. Trigger
information from electrically noisy sources such as high current discharge laser systems may be
transmitted without conducting Electro-Magnetic Interference, (EMI) to the measurement or control
equipment.
Thees systems transmit an analog signal plus four digital input channels simultaneously. The input
analog signal may range in frequency from DC to 12.5 MHz (-3 dB point) for the LTX5510 and DC to
25 MHz (-3 dB point) for the LTX5515. The digital signals may switch at up to 12 MHz rates for the
LTX5510 and at up to 25 MHz rates for the LTX5515, and are independent. The analog input may
be terminated at 1 Megohm or 50 Ohms depending on the front panel switch. The output impedance
is always 50 ohms. Analog signals may range from -5 to +5 volts. The output signal will have a one-
to-one correspondance, i.e. a gain of +1. When the front panel selector switch is set to +/- 1V F.S.
the gain is +5, ie. a 1 volt input signal will result in a five volt output signal. The digital inputs accept
TTL, CMOS or LVTTL levels and output LVTTL levels, i.e. 0 to 3.3V for a logic zero and logic one
respectively. The sense is non-inverting.
1
Unpacking and Inspection
Prior to shipment this instrument was inspected and found to be free of mechanical and electrical
defects. Upon acceptance by the carrier he assumes responsibility for its safe arrival. After unpacking,
examine the unit for any evidence of shipping damage. Should you receive this instrument in a
damaged condition, apparent or concealed, it must be noted on the freight bill or express receipt and
signed by the carrier’s agent. Failure to do so could result in the carrier refusing to honor the claim.
Upon filing a claim TTI should be notified.
Power Considerations
The LTX-551X Transmitter and Receiver operate from a regulated 9 VDC wall-mount power supply.
These power supplies operate with line voltages ranging from 95 to 260 VAC, 50-60 Hz. Four
interchangeable power line connectors are supplied that are compatible with connectors used in
North America, Continental Europe, Australia, and the United Kingdom. Do not use with any other
wall-mount supply or damage may result.