LITE-ON

TECHNOLOGY

CORPORATION

Alex Chu 2011/10/6

P r o p e r t y o f L i t e - O n O n l y

Part

No. : LTST-S271KFKT

Page :

10

of

12

BNS-OD-C131/A4

5. 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

Circuit model B

LED

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.

6. ESD (Electrostatic Discharge)

Static Electricity or power surge will damage the LED.

Suggestions to prevent ESD damage:

Use of 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 LED’s

plastic lens as a result of friction between LEDs during storage and handling.

ESD-damaged LEDs will exhibit abnormal characteristics such as high reverse leakage current, low forward

voltage, or “ no lightup ” at low currents.

To verify for ESD damage, check for “ lightup ” 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.