Hi,
im trying to drive the leds of 7-segments-display (2 digits) with an STM32. I'm using MOSFET transistors to control the segments. I came up with the following circuit (attached).
I got a 3.3V supply and i want to get 10mA on each LED of the display. Can you tell me please if the circuit will work and if my calculations of the resistors are correct?
I calculated the voltage drop of 1V (3.3V - 2V from the LEDs and - 0.3V from the MOSFET). It resulted in 1V / 0.01A=100 Ohm. So i took the 95 resistors. Is this optimal?
Also i would like to know the following:
1) do i need a gate resistor on each MOSFET? If yes, what is the right value and how to calculate it.
2) I chose the pull-up resistor for the P-MOSFET 10k Ohm. Will it be enough?
3) Do i need to add any other elements to the circuit?
Thanks!
im trying to drive the leds of 7-segments-display (2 digits) with an STM32. I'm using MOSFET transistors to control the segments. I came up with the following circuit (attached).
I got a 3.3V supply and i want to get 10mA on each LED of the display. Can you tell me please if the circuit will work and if my calculations of the resistors are correct?
I calculated the voltage drop of 1V (3.3V - 2V from the LEDs and - 0.3V from the MOSFET). It resulted in 1V / 0.01A=100 Ohm. So i took the 95 resistors. Is this optimal?
Also i would like to know the following:
1) do i need a gate resistor on each MOSFET? If yes, what is the right value and how to calculate it.
2) I chose the pull-up resistor for the P-MOSFET 10k Ohm. Will it be enough?
3) Do i need to add any other elements to the circuit?
Thanks!
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