http://www.onsemi.com/pub_link/Collateral/AND8109-D.PDF
The above link is an LED constant current source scheme.
http://www.onsemi.com/pub_link/Collateral/AND8109-D.PDF
I am concerned about the Figure-4.
I am making the similar circuit but instead of 3 LEDs i have 4 LEDs in series and instead of 3 parallel connection i have 2 parallel connection. The LEDs work on 20mA and 2.2V each.
I wanted to know how to calculate the resistor value.
The above link is an LED constant current source scheme.
http://www.onsemi.com/pub_link/Collateral/AND8109-D.PDF
I am concerned about the Figure-4.
I am making the similar circuit but instead of 3 LEDs i have 4 LEDs in series and instead of 3 parallel connection i have 2 parallel connection. The LEDs work on 20mA and 2.2V each.
I wanted to know how to calculate the resistor value.