TOTX173A(F)
2007-03-08
3
(3) Life of light emitters
When the optical module is used for over a long period, degeneration of characteristics is mostly due to
lowering of the fiber output power (Pf). This is caused by the degradation of the optical output of the LED’s
used as the light source. The cause of degradation of the optical output of the LED’ may be defects in
wafer crystallization or mold resin stress. The detailed causes are, however, not clear.
The life of light emitters is greatly influenced by operating conditions and usage environment as well as the
life characteristics unique to the device. Thus, when selecting a light emitter and setting the operating
conditions, Toshiba recommends that you check the life characteristics.
Depending on the environment conditions, Toshiba recommends maintenance such as regular checks on
the amount of optical output.
(4) Soldering
Optical modules use semiconductor devices internally. However, in principle, optical modules are optical
components. At soldering, take care that flux dose not contact the emitting surface or detecting surface.
Also take care at flux removal after soldering.
Some optical modules come with protective cap. The protective cap is used to avoid malfunction when the
optical module is not in use. Not that it is not dust or waterproof.
As mentioned before, optical modules are optical component. Thus, in principle, soldering where there
may be flux residue or flux removal after soldering is not recommended. Toshiba recommends that
soldering be performed without the optical module mounted on the board. Then, after the board is cleaned,
solder the optical module manually. Do not perform any further cleaning.
If the optical module cannot be soldered manually, use non−halogen (chlorine−free) flux and make sure,
without cleaning, there is no residue such as chlorine. This is one of the ways to eliminate the effects of
flux.
(5) Vibration and shock
This module is resin−molded construction with wire fixed by resin. This structure is relatively sound against
vibration or shock, In actual equipment, there are some cases where vibration, shock, and stress is
applied to soldered parts or connected parts, resultingin line cut. Attention must be paid to the design of the
mechanism for applications which are subject to large amounts of vibration.
(6) Fixing fiber optical transmitting module
Solder the fixed pin (pins 5 and 6) of fiber optic transmitting module TOTX173A (F)to the printed circuit
board to fix the module to the board.
(7) Solvent
When using solvent for flux removal, do not use a high acid or high alkali solvent. Be careful not to pour
solvent in the optical connector ports. If solvent is inadvertently poured there, clean with cotton tips.
(8) Protective cap
When the fiber optic transmitting module TOTX173A(F) is not in use, use the protective cap.
(9) Supply Voltage
Use the supply voltage within the operating condition (VCC = 5 ± 0.25 V). Make sure that supply voltage
does not exceed the absolute maximum rating value of 7 V, even instantaneously.
(10) Input voltage
If a voltage exceeding the absolute maximum rating value (VCC + 0.5V) is applied to the transmitter input,
the internal IC may degrade causing some damage. If excessive voltage due to surges may be added to
the input, insert a protective circuit.
(11) Soldering condition
Solder at 260°C or less for no more than ten seconds.
(12) Precaution on waste
When discarding devices and packing materials, follow procedures stipulated by local regulations in order
to protect the environment against contamination.
Compound semiconductors such as GaAs are used as LED materials for this module. When discarding
waste or at final processing, attention must be paid to workers and the environment.