In a capacitor-input type rectifier circuit, inrush current
flows when the power supply is switched on. The peak
value of this inrush current shall be set less than peak
forward surge current I
but set the minimum pulse width to 1 msec). The value
inrush current is repeated within a short period of time,
the derating has to be taken into account.
When forming leads, hold the lead wire on the main
body’s side so as to prevent stress from being applied
to the main body.
To mount a frame-type diode on a heatsink, use its
screwhole. Do not fix its resin body as the silicon chip
may get broken.
For an axial type diode, measure the temperature of the
lead wire on the main body side. The thermocouple to
be used must be as thin as possible (approximately
A diode’s temperature increases due to losses from
forward current, reverse current and reverse recovery
In normal use, losses are mainly attributable to forward
current and voltage. However, in high frequency
circuits such as switching power supplies, losses due to
reverse recovery time also occurs. Moreover, in diodes
having large reverse currents like Schottky barrier
diodes losses due to reverse current cannot be disre-
Forward loss tends to decrease at high temperatures.
However, reverse loss tends to increase at high tem-
peratures. Therefore, it is necessary to consider the
ambient temperature when verifying operation.
is guaranteed for a single shot only. If the
t can also be obtained
Contact us if there is any unclear point.
Soldering (flow, reflow)
Peak value current
Limit of the peak value current must be set to 10 times
of the average current (I o or I
If the peak value increases. the diode’s forward loss
also increases. In this case, check the temperature rise.
usage environment is prone to creeping discharge.
ii) To prevent the build-up of large thermal stress,
iii) When using a soldering iron, make use of the
Surface Mount Diodes
i) Use rosin based flux. Never use acidic fluxes.
Carefully study the mounting method when the
preheat within 1 to 2 minutes at 150ºC and solder
within the usable range shown below.
Temperature of soldering Iron Tip:
Soldering time: less than 10 seconds
: Copper foil land for
mounting SFP series
4.0 to 4.2
less than 300ºC
(Power of the soldering
iron: 30W or less)
The soldering tip must
be as thin as possible.
) under normal use.