how to read a datasheet led part 1

7/24/2019 How to Read a Datasheet LED Part 1

1/15

Welcome to this presentation on How to Read a Datasheet Part One of Two,

part of OSRAM Opto Semiconductors LED Fundamental series.

In this presentation we will examine the key parameters specified on every

page of an LED datasheet from OSRAM Opto Semiconductors.


2/15

The datasheet captures some of the most important technical characteristics

of an LED. These include electrical, optical, and thermal quantities;

knowledge of which is paramount for an LED system design.

Also, it has information on ordering codes, labeling, and packaging of theLEDs.

We will look at each one of these quantities in detail as we flip through each

page of a datasheet. In this presentation we will look at the OSLON SSL

datasheet.


3/15

Pa e 1 of the datasheet ives a brief sna shot of the most im ortant

features of the LED.

It lists a few key applications where this LED could be used and also has a

picture of the LED package.


4/15

Page 2 lists the type numbers for specific color temperatures. Type numbers

represent the order groups which include only a few brightness groups,

chromaticity coordinate groups, and forward voltage groups.

An explanation of a type number is listed on this slide. For example, thetype number LUW CP7P-KSKU-5E8G-35 contains only one brightness

group KS, KT, and KU: one chromaticity coordinate group from 5E to 8G:

and one forward voltage group 3, 4, or 5 will be shipped for any one reel.

The luminous flux min to max range for each type number indicates the

minimum value of the lowest bin to the maximum value of the highest bin

available.

An ordering code, or a Q number, is assigned to each type number and is

generally used to enter sample order requests for specific type numbers.


5/15

Page 3 lists the maximum ratings for temperature, forward current, and

surge currents.

These maximum values should not be exceeded in the system design.


6/15

Page 4 lists the typical values for chromaticity coordinates at the binning

current and solder point temperature of 25C. Chromaticity coordinates are

measured during a current pulse of 25 ms, with an internal reproducibility of

+/- 0.005 and an expanded uncertainty of +/- 0.01.

The viewing angle, which is the full width half maximum of the luminous

intensity of the LED is listed in degrees.

The minimum, typical, and maximum values of forward voltage at binning

current are listed.

Forward voltage is measured during a current pulse of 8 ms, with an internal

- . - . .

Typical optical efficiency, which is the ratio of output lumens to supplied

electrical power, is given in lumens/watt.

T ical and maximum values of thermal resistance from unction to solder

point of the LED package is listed in K/W.


7/15

Page 5 of the datasheet has a plot of the binning groups linked to the type

numbers listed on Page 2 of the datasheet on the CIE 1931 chart.


8/15

Page 6 gives the chromaticity coordinates of each bin shown on Page 5.


9/15

Page 7 lists the brightness and voltage groups available. The min and max

luminous flux value and typical intensity value is listed for each brightness

group.

Similarly, the min and max values for each voltage group are also specified.Individual brightness or voltage groups cannot be ordered.

On the other hand, no reel of parts ever contains more than one brightness

group or forward voltage group.


10/15

Page 8 overlays the typical spectral emission curve of the LED at room

temperature and binning current on the human eye response curve.


11/15

Page 8 also shows the radiation characteristics of the LED.

The angle where the luminous intensity decreases to 50% of the maximum is

defined as the viewing angle for the LED.

For the OSLON SSL the radiation curve hits the 50% line at an angle of ().

Therefore, the viewing angle (2 ) is 80.


12/15

This slide is a deviation from the exemplary datasheet of LUW CP7P being

discussed to a monochromatic LED datasheet such as LA CP7P to illustrate

a few key parameters mentioned in a monochromatic LED datasheet.

Monochromatic LEDs specify peak wavelength, dominant wavelength, andspectral bandwidth.

Dominant wavelength is the single wavelength that is perceived by the

human eye, and is defined as the wavelength of monochromatic light that

has the same apparent color as the light source.

Peak wavelength is defined as the single wavelength where the radiometric

.

Spectral Bandwidth is the wavelength interval in which a radiated spectral

energy is not less than half its maximum value.


13/15


14/15


15/15

For information on characteristic curves, dimensions, and packaging please

refer to part two of How to Read a Datasheet.

Thank you for viewing this presentation by OSRAM Opto Semiconductors.

how to read a datasheet led part 1

Documents