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Author Topic: TLC5940 Overheating (Daisy Chain) ( Electronic Beer Pong Table)  (Read 4512 times)
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So what has changed since the last session?
Was everything likewise smoothly going in past sessions, too?
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So what has changed since the last session?
Was everything likewise smoothly going in past sessions, too?

Since the previous sessions (Fried IC's), I have added multiple 1uf and 100uf Capacitors along the railings. I didn't expect it to work as flawlessly as it did!
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So, you've exceeded past run times now and heat is a thing of the past?
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So, you've exceeded past run times now and heat is a thing of the past?

Yes, the past run times were from 5 to 40 minutes. I'm going to call Texas Instruments tomorrow to verify that the Max Ouput of 120mA is for a single OutX. I'll let you guys know.
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I guess it's a take at this rate.
I hope you don't figure that I'm "against you" or anything like that.
If it hangs in there and everything is everything then good on you.
Thermal runaway for lack of some bypassing...[scratches head, mutters]...

Here's hoping somebody at TI takes that call and can give a definitive answer on what constitutes "Absolute Max" (pkg, output, per output, or what.)
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I guess it's a take at this rate.
I hope you don't figure that I'm "against you" or anything like that.
If it hangs in there and everything is everything then good on you.
Thermal runaway for lack of some bypassing...[scratches head, mutters]...

Here's hoping somebody at TI takes that call and can give a definitive answer on what constitutes "Absolute Max" (pkg, output, per output, or what.)

Thanks for the help and concern, I appreciate it!
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"BTW....since dot correction was not stated as being used, DCn=0."
No way!  Does nixing pixel correction imply 0, does the datasheet state that?  If that was so, as you noted, then you could do whatever you wanted because everything there gets multiplied by "0/63=0" and everything would then be "0", a free play, and that would make zero sense.
Yes, the datasheet does talk about dot correction being in the range of 0 to 63 or 64 steps from 0% to 100% of the maximum output current Imax (page 15).

Review Order of math operations: http://en.wikipedia.org/wiki/Order_of_operations then apply it to the equation.  It doesn't make the whole thing zero...just everything past the '+' sign. smiley   
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I get your "argument", Cranium, but your contention that not using dot correction results in DCn/63 = 0, implying a free pass on the consequences of everything to the right of the addition sign, is false. 
If it's not specified then DCn/63 = 1 (nothing gets turned down for matching.) 
If DCn/63 = 0 then the output would be off .

Yes, Page 15 --
Setting Dot Correction:
I_out = I_maxA * (DCn / 63)
If DCn/63 = 0, then I_out = 0.

A - R_iref (Pg. 14)
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Yes, Page 15 --
Setting Dot Correction:
I_out = I_maxA * (DCn / 63)
If DCn/63 = 0, then I_out = 0.

I stand corrected.  You are right on this point. smiley
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