Foremost, I'm sorry if I am wrong with something. I want to "develop" a project with some bi-color LED (OSRAM LSY-T676). I have created (after some tutorials) my own component because it was not included in Proteus 8 library. Source which is used is a car battery (12V), LEDs have Forward Voltage 2V for both colors and Forward Current 20mA (nominal). I need to use 20 pcs of this LEDs, so I make 4 groups of 5 LEDs (10V Forward Voltage). After basics calculation, 100ohm resistor is needed to obtain the correct current.

I'm searching to control LEDs with a uc PIC12F675 ( as I read in datasheet: current 25mA and Vdd-0.7V => 5-0.7= 4.3V output if Vdd will be 5V as I want). Idea was to use a MOSFET-N 2n7000 (Vgs(th) =2.1V Id=115mA) but I'm not really sure if all data for uc and MOSFET were interpreted correctly by me. Could you, please, correct me, if somewhat is wrong? My questions are:

1.What is the maximum frequency for PWM (because I want to control LEDs via PWM).

2.How to calculate the Base resistor?

3.Is needed a parallel capacitor? ( I saw some examples on forums). If is needed, how can I calculate the value.

4. What is the influence of RDS(on)? (As I understood is one of the most important characteristic)

Thank you for your time.

I want to "develop" a project with some bi-color LEDs (OSRAM LSY-T676.) I have made (after some tutorials) my own component because it was not included in Proteus 8 library. Source which is used is a car battery (12V), the LEDs have a forward voltage of 2V for both colors and a forward current of 20mA (nominal.) I need to use twenty of these LEDs, so I made four groups of five LEDs (10V forward voltage.) After basic calculation, a 100ohm resistor is needed to obtain the correct current.

I'm want to control the LEDs with a PIC12F675 microcontroller (as I read in datasheet: current 25mA and Vdd-0.7V => 5-0.7= 4.3V output if Vdd will be 5V as I want.) The idea was to use a 2N7000 N-channel MOSFET (Vgs(th) =2.1V Id=115mA) but I'm not really sure if I interpreted the data for the microcontroller and MOSFET correctly. Could you, please, correct me, if somethingbis wrong? My questions are:

1. What is the maximum frequency for PWM (I want to control LEDs via PWM.)
2. How should I calculate the base resistor?
3. Do I need a parallel capacitor? (I saw some examples on forums.) If it is needed, how can I calculate the value?
4. What is the influence of RDS(on)? (As I understood is one of the most important characteristic)