LTL-4221N Datasheet, PDF (6/7 Pages) Lite-On Technology Corporation – High Intensity.

LITE-ON TECHNOLOGY CORPORATION
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6. Drive Method
An LED is a current-operated device. In order to ensure intensity uniformity on multiple LEDs
connected in parallel in an application, it is recommended that a current limiting resistor be
incorporated in the drive circuit, in series with each LED as shown in Circuit A below.
Circuit model A
LED
Circuit model B
LED
(A) Recommended circuit
(B) The brightness of each LED might appear different due to the differences in the I-V characteristics
of those LEDs
7. ESD (Electrostatic Discharge)
Static Electricity or power surge will damage the LED.
Suggestions to prevent ESD damage:
„ Use a conductive wrist band or anti- electrostatic glove when handling these LEDs
„ All devices, equipment, and machinery must be properly grounded
„ Work tables, storage racks, etc. should be properly grounded
„ _{Use ion blower to neutralize the static charge which might have built up on surface of the LEDs}
plastic lens as a result of friction between LEDs during storage and handing
ESD-damaged LEDs will exhibit abnormal characteristics such as high reverse leakage current, low
forward voltage, or “no light up” at low currents. To verify for ESD damage, check for “light up” and
Vf of the suspect LEDs at low currents.
The Vf of “good” LEDs should be >2.0V@0.1mA for InGaN product and >1.4V@0.1mA for AlInGaP product.
Part No. : LTL-4221N
BNS-OD-C131/A4
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