pmphilip

Hello Friends,

I have a led display for 16*16 matrix display. This matrix display is 32 pin led display. I need a led display driver for the circuit. I searched the internet but I did not find any datasheet for the 16*16 matrix led display.
Can any one help how to find out datasheet for the 16*16 matrix led display?. The led 16*16 led matrix led display can found in the website given belwo www.rohm.com. This IC is manufactured by rohm.

I have attached the datasheet 16*16 matrix led display . If datasheet could not be found. How can I construct a driver circuit for the led display.

Hoping for a reply

Philip

Attached Files

lm-1256.pdf (99.8 KB, 253 views)

bonxer

The ancient art of brute force testing.

Actually I have some bi-colored 8x8 LEDs, which have a red and a green LED in each cell, so I guess theoretically it would be a 16x8 LED matrix, although it's an 8x8 cell grid. Here is the diagram that goes with them. This is for the common anode version. For instance you turn voltage on to pin 22, and then load your active low data on the 16 column pins to display the first line of red and green patterns. Then you turn off your data lines and ground pin 22. Now turn on pin 19, and load your active low columns to display the second row of patterns. Please note that these pins could be quite different for the rows and columns of your device, this is just to give you an idea of the innards.

I've never worked with a 16x16, but I would imagine it is very similar. As you can see, my 8x8 is a 24 pin device. 8 common anode lines, and 16 cathode lines. So it makes sense to assume your 32 pin device it 16 cathodes, and 16 anodes. Your device could be common cathode, with active high data loaded onto the anodes. Just experiment and you'll figure it out.

The only thing that bothers me is the possibility of 16 independent cathodes. I've never worked with that many operating mutually exclusive like that. I've even gone so far as to have data lines latched and run multiple 8x8's in parallel, to keep the duty cycle at a nice clean 1/8 rate.

I've always thought that the lowest acceptable duty cycle for an LED was 1/10th. 1/8th is the lowest I've ever done in practice. A 1/16th duty cycle might be acceptable, but I would have to imagine it would look quite dim.

Attached Images

	ledm8x8rg.jpg (25.8 KB, 554 views)
	8x8bicolor.png (16.6 KB, 548 views)

pkeberly

Take a look at Maxim IC. They have a chip that might help you out
http://pdfserv.maxim-ic.com/en/ds/MAX6960-MAX6963.pdf

PK