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So I have 3072 RGB LEDs I need to connect in a matrix.

I have decided to split the project into smaller matrices and all LEDs are common Anode.

Datasheet for LEDs is here: http://docs-europe.electrocomponents.com/webdocs/13dd/0900766b813dd0f4.pdf

Im thinking about splitting it into 4x 16x48 matrices which would be 48 Anode pins and 48 Cathode Pins (16 for each colour).

Im struggling to work out which ICs to use to drive the LEDs.

What LED drivers would be suitable for driving a 48x16(x3) matrix?

Is there any suitable LED drivers ideally with 48outputs that would drive a matrix of this size directly or will I need a current sink/source as well as the driver / expander chip?

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  • \$\begingroup\$ In principle the WS2801, although that is probably fairly expensive in large quantities. \$\endgroup\$ – Simon Richter Dec 27 '15 at 19:46
  • \$\begingroup\$ I was thinking a chip with more like 48 outputs so save on cost / component count \$\endgroup\$ – Terry Gould Dec 27 '15 at 20:12
  • \$\begingroup\$ What are you going to display? What kind of update rate do you need? Are you trying to display text, pictures or video? \$\endgroup\$ – vini_i Dec 27 '15 at 20:20
  • \$\begingroup\$ Im never going to be displaying video just simple patterns. I need the illusion that all LEDs are on at the same time. But the pattern will only update around every second. \$\endgroup\$ – Terry Gould Dec 27 '15 at 22:53
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I am not aware of any driver ic with that number of outputs. But there are solutions. If you don't need fast refresh rates or high pwm resolution, you could use a microcontroller as a driver. you can get a beefy one and code a pwm algorithm that will use one timer and as many gpios as possible to drive the mosfets that will switch your leds on and off. I work with PICs and the 122pin pic32mz comes to my mind. Attach many of them as slaves with different adresses in an i2c bus and you are in business.

The adresses can be set with dip switches so you don't have to write different code for each of the uC.

Whatever you chose won't come cheap though at this number of leds.

If you provide us with the displayed material and the refresh rates I can give you a detailed answer with a more detailed analysis as far as timing and cost is concerned.

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  • \$\begingroup\$ It would be typical to daisy chain driver ICs for this purpose. That could be a basic shift register or a fancy LED driver with grey scale / PWM / per LED brightness compensation. Where high speed is needed a CPLD or FPGA could handle the multiplexing and send data to the drive ICs. This would be far more efficient than many pins on a microcontroller. \$\endgroup\$ – David Dec 27 '15 at 22:55
  • \$\begingroup\$ I don't need fast refresh rates, I'm never going to be displaying video only simple patterns. Surely a micro controller will not be able to supply enough current to run the LEDs directly. \$\endgroup\$ – Terry Gould Dec 27 '15 at 23:02
  • \$\begingroup\$ You are correct @ProductDesigner that most ICs can source or sink a fairly small amount of total current and this may be less than the maximum current per pin * total pins. \$\endgroup\$ – David Dec 27 '15 at 23:08

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