TOTX195 Datasheet, PDF (6/8 Pages) Toshiba Semiconductor – FIBER OPTIC TRANSMITTING MODULE

TOTX195
7. Precautions during use
(1) Maximum rating
The maximum ratings are the limit values which must not be exceeded during operation of device.
None of these rating value must not be exceeded. If the maximum rating value is exceeded, the
characteristics of devices may never be restored properly. In extreme cases, the device may be
permanently damages.
(2) Lifetime of light emitters
If an optical module is used for a long period of time, degeneration in the characteristics will mostly
be due to a lowering of the fiber output power (Pf). This is caused by the degradation of the optical
output of the LEDs used as the light source. The cause of degradation of the optical output of the
LEDs may be defects in wafer crystallization or mold resin stress. The detailed causes are, however,
not clear.
The lifetime of light emitters is greatly influenced by the operating conditions and the environment in
which it is used as well as by the lifetime characteristics unique to the device type. Thus, when a light
emitting device and its operating conditions determined, Toshiba recommend that lifetime
characteristics be checked.
Depending on the environment conditions, Toshiba recommend that maintenance such as regular
checks of the amount of optical output in accordance with the condition of operating environment.
(3) Soldering
Optical modules are comprised of internal semiconductor devices. However, in principle, optical
modules are optical components. During soldering, ensure that flux does not contact with the emitting
surface or the detecting surface. Also ensure that proper flux removal is conducted after soldering.
Some optical modules come with a protective cap. The protective cap is used to avoid malfunction
when the optical module is not in use. Note that it is not dust or waterproof.
As mentioned before, optical modules are optical components. Thus, in principle, soldering where
there may be flux residue and flux removal after soldering is not recommended. Toshiba recommend
that soldering be performed without the optical module mounted on the board. Then, after the board
has been cleaned, the optical module should be soldered on to the board manually.
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. In such a cases, be sure to check the devices’ reliability.
(4) Vibration and shock
This module is plastic sealed and has its wire fixed by resin. This structure is relatively resistant to
vibration and shock. In actual equipment, there are sometime cases in which vibration, shock, or
stress is applied to soldered parts or connected parts, resulting in lines cut. A care must be taken in
the design of equipment which will be subject to high levels of vibration.
(5) Attaching the fiber optic transmitting module
Solder the fixed pins (pins 4 and 5) of the fiber optic transmitting module TOTX195 to the printed
circuit board in order to fix it to the board.
(6) Solvent
When using solvent for flux removal, do not use a high acid or high alkali solvent. Be careful not to
pour solvent in to the optical connector ports. If solvent is inadvertently poured in to them, clean it off
using cotton tips.
(7) Protective cap
When the TOTX195 is not in use, attach the protective cap.
(8) Supply voltage
Use the supply voltage within the recommended operating condition (VCC = 5 ± 0.25 V). Make sure
that supply voltage does not exceed the maximum rating value of 7 V, even for an instant.
(9) Input voltage
If a voltage exceeding the maximum rating value (VCC + 0.5 V) is applied to the transmitter input,
the internal IC may suffer damage. If there is a possibility that excessive voltage due to surges may
be added to the input terminal, insert a protective circuit.
(10) Soldering condition
Solder at 260°C or less for no more than three seconds.
(11) Precautions when disposing of devices and packing materials.
When disposing devices and packing materials, follow the procedures stipulated by local regulations
in order to protect the environment against contamination.
Compound semiconductors such as GaAs are used as LED materials in this module. When devices are
disposed of, worker safety and protection of the environment must be taken into account.
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2001-08-10