Agilent LEDTest Solutions

Let’s think for a moment:

What are the methods available to test an LED ?

How can board topologies affect the test coverage for LED?

Can these be done at the ICT – REALLY?

Agilent LEDTest Solutions

What are the methods available to test an LED ? • Forward Voltage measurement • Forward Current measurement • Color and Intensity measurement • Lighting Sequence and Interval tracking How can board topologies affect the test coverage for LED? • Devices connected in parallel • Limited access to device

Forward Voltage Measurement (LV Mode ) Forward Voltage Measurement (LV Mode) • Apply stimulus voltage up to 9.9V • Measures voltage drop by the LED Benefits • Simple to implement and Fast to execute • No hardware cost Limitations • Ineffective when LED/Diodes are in parallel (eg, protection diode in IC) • No Color and Intensity coverage • No lighting sequence coverage

Forward Voltage

Forward Current Measurement (FC Mode )

Forward Current

Forward Current Measurement (FC Mode) • Apply stimulus voltage up to 9.9V • Measures current drawn by the DUT Benefits • Simple to implement and Fast to execute • No hardware cost • Resolved Parallel diodes/LED situation Limitations • No Color and Intensity coverage. • No lighting sequence coverage

Color and Intensity Measurement Color and Intensity Measurement • Uses 3rd party fixture electronics (eg, SmartFinn, Feasa, etc) • Measures voltage and frequency or • Using EXT to read values from sensor device. Benefits • No topology restrictions • Reports results in Wavelength(Color) and Voltage(Intensity) Limitations • Hardware cost involved for fixture • No lighting sequence coverage • Sensitive to environmental lighting

LED Application

TRANSMISSION LOSS

air

plastic

glass

RADIATING ENERGY

Manufacturing LED

Color (nm) Luminous Intensity (mcd) Dispersion

Concept of testing Color and Intensity

IRRADIATING ENERGY

mW/cm2

LED DATASHEET

Optic fiber

medium

LED sensor

ICT Fixture

PCB

Color and Intensity Test will : 1. Not measure the same intensity specified

in the datasheet because the ICT test setup is different.

2. Measure the color in nanometers within a few percent of the datasheet’s nominal color specification.

Medium of Transmission Source of Light Target

COLOR INTENSITY

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Agilent LEDTest Box

Agilent LEDTest Box • Connected through TCPIP • Triggered by EXT mode in i1000 software. • Supports up to 128 sensors Benefits • Simple to implement and Fast to execute • No topology restrictions • Color and Intensity coverage • Lighting sequence coverage Limitations • Hardware cost involved for fixture • Sensitive to environmental lightings

Agilent LEDTest Box Hardware installations

Cascade up to 4 mux cards

Each Mux supports 32 Sensors

LED Test Box

DUT

Agilent LEDTest Box Software setup

Power on DUT

Start LEDTEST

Light LED

End LEDTEST

Get Result

• Triggered by EXT mode in i1000 software. • Collects LED activities over specified time duration. • Measurement result analyzed by LEDTEST Application. • Other tests (Bscan, Digital, etc) can be executed while LEDTEST is

collecting measurements. Saves Time !

Agilent LEDTest Box

Agilent LEDTest Box • User defined test limits at any time in the test duration • Captures the LED lighting sequence. Not just simple ON/OFF. • Tests R, G, B and Intensity all at the same time !

R

G

B

Y