Switching question

[adinogcas]

Hi all,

I need advices in this problem. I have an array of LEDs ,say 4-7 LEDs, I want to design a circuit that can turn on and off those LED alternatively. The turn on and off signals are from uC. Should I use IC switch? or use an array of transistor (or FETs)?

Each LED will have 100mA go through to turn it on, so using uC is impossible to turn on the LED so just use it to signal switches to connect LEDs and power supply (3.3V).

The turn on/off will be 500us for each LEDs, for example:
0-500us: LED 1 is on, others are off
500-1000us: LED 2 is on, others are off
1000-1500us: LED 3 is on, others are off
and so on...

I need the switch that can turn LED on and off COMPLETELY. If possible can you provide me the name of the parts? There are hundreds of components...so I need advice on choosing the switches too.

Really appreciate any help in this problem,

 

[MikeMl]

2n3904, 2n4401, 2n4124, 2n5550, ... I could go on and on. Dont forget the base resistor, and a resistor in series with the LED to limit forward current. 3.3V for the LED supply is too low, especially if the forward voltage drop of the led is over 3V.