8 digit 7 segment - runs off 8V: too much for MAX7219 - options?


I'm trying to make a large counter with 8x7 segment displays, driving it with a multiple through an arduino uno. They displays are quite large and the LEDs run off 8V and won't even light up with 5V. The problem is my driver (MAX 7219 CNG) is only capable of 5V... so how do I fix this? Common anode would be easy: an npn transistor for each display but my 7 segment displays are common cathode.

Is there a suitable alternative to the MAX7219 I can buy or an IC that has many transistors that is easy to add to my breadboard?



You can use an octal inverter like a 74HC540 after the MAX chip to change the common from one to the other.

You didn't Google did you?

First hit is an app note from Maxim about it ;)

Max7219 is designed for common cathode. But not for higher voltage.

Another option would be a couple of tpic6c595 and some PNP transistors, if it's OK to have the Arduino do the multiplexing.