• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

LED Multiplex Current Requirements

Not open for further replies.


Active Member
I’m doing a 16 rows & 48 column LED matrix design. I’m scanning rows @ 1/16th rate. Designed for 4mA average current to the LEDs. I’m doing a 5V design, but For LEDs I can increase supply more than 5V.

One row will take 4mA X 16 X 48 = 3072mA. But this is maximum it will be less than this…!!!

1) To supply above current is my base resister value ok?
2) To make it better performance is there any optional transistor value than MOSFETs?
3) To make my LEDs brighter is my LED supply voltage 5.4V enough?



I am not offending you.....

This is a begineer's design. You need a lot of PICs to control them like this. I don't see the matrix pattern here. "5.4VDC" is a dangerous supply for MCUs, their maximum is "5.5VDC".

This circuit is what you need.

LED displays are very energy consuming and inefficient. An LCD is better.


Active Member
No, The PIC have a 5V supply.Only for LEDs I have a variable power supply.You dont need lots of PICs.YOu just need only one PIC.
Not open for further replies.

Latest threads

EE World Online Articles