Saturday, 11 May 2019

bjt - PNP transistor to command LED



Usually I use NPN to drive LEDs but in my project I have to use PNP because the cathode of the LED is tied to GND.


Then I have a question, is it possible to have a command of 3.3V and the PNP tied to the 5V.


I am thinking it is not possible because if the command is at 0 the BJT is saturated and everything is OK but if the command is at 3.3V then Veb= 5-3.3=1.7>0.7 and the BJT is still not blocked.


Am I right?




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