Hi,
I have some common cathode 8*8 LED Matrix that I want to drive from Arduino.
Can anyone suggest an IC I can use for swithing the high side - worst case 8 leds on at 5ma each or 16 leds at 5ma if I chain two Matrix to a single IC.
I am happy to do the multiplexing through a seperate IC, its the current I am after - 80ma per line would be good, 160ma would be great.
Any suggestions ?
Duane B
Use a MAX7219 8x8 LED matrix driver IC...?
Hi,
I am having a look now, but always thought they were very expensive for what they do.
Duane B
MAX7219 is easy to do and well supported but be aware you cannot PWM individual LED's only the entire 64 so if that's what your project needs then maybe the TLC5940 and a shift register.
Look for MAX7219 on ebay, you can pick them up a lot cheaper.
Hi,
Just had a look at the 5940, its a current sink, I want a current source.
Ideally I don't want any logic in the IC, I have that covered by the Arduino and 4017 counters.
All I am looking for is to switch more current, worst case I will use individual transistors but there must be an off the shelf package like the 2803 but for the high side ?
Duane B
DuaneB:
Just had a look at the 5940, its a current sink, I want a current source.
Sorry, having a bit of a blonde moment, missed the source bit 
How many volts?
The MIC94070 and friends are good for 5v5. Only a single switch though.
EDIT: The MIC2514 can handle 13v5.
Rob
Hi,
The best description I can give is a 2803 but for high side switching.
The MIC94070 is an interesting chip, as suggested by Graynomad, its only one output, but with a low price and 1.2A of current its a viable option and easily able to handle the worst case of 16 leds on.
If there isn't a a high side 2803 equivalent I will go with 8 * MIC94070 or one of its close relative
Thanks
Duane B
DuaneB:
I am having a look now, but always thought they were very expensive for what they do.
That's relative to what you're doing with them.
You can get them a lot cheaper on eBay (they'll be Chinese clones but they work the same...)
You could use MIC5981, http://www.micrel.com/_PDF/mic5891.pdf. It has 8 active high outputs capable of sourcing up up 500mA (not all at once!) at up to 50V, and serial input. However, it has a Darlington output, so the voltage drop is rather high (2V @ 350ma).
Nice chip, filed for future reference.
Rob
Hi,
Going to try the 5891
Thanks for all the suggestions
Duane B