Peak Atlas DCA Pro User Guide June 2019 – Rev 1.7
Page 12
Bicolour LEDs (2-lead types)
Bicolour LEDs are generally available in two main
varieties; 2-lead and 3-lead types.
This section describes the testing of 2-lead bicolour
LEDs. These types are internally connected in inverse-parallel
(back-to-back).
Similar to the diode network analysis, each LED within the bicolour LED is
detailed in turn.
This example shows that LED #1 has its
Cathode connected to the Red test clip
and its Anode connected to the Blue test
clip. The forward bias characteristic is
shown for LED#1, 1.823V at 5mA in
this example.
Pressing scroll-off then shows the
details for the 2
nd
LED in the bicolour
LED package.
As expected for 2-lead bicolour LEDs, we can see in this example that LED#2
has its connections in exactly the opposite configuration to LED#1.
Note that it is common for the two LEDs within a bicolour LED to have
different forward voltage characteristics. Red is often the lowest forward
voltage, progressing through amber, yellow, yellow-green, pure-green
and then blue (or white) with the highest forward voltage. See the table
at the bottom of the next page.
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