LED displays (TIL305, TIL308, etc.)

[Chuck Guzis]

On 1 Oct 2008 at 17:38, Roy J. Tellason wrote:

> Whoops,  you're right,  that's exactly what I was thinking of,  though I'm 
> pretty sure I was also remembering Motorola...
> 
> Perhaps one of those two companies was second-sourcing the other.
> 
> All of my databooks are currently in boxes,  and I'm not even sure which ones 
> are in what boxes,  a situation that I'm hoping to correct somtime soon,  so 
> I can't verify my recollection on this.

Okay, I dug out my Moto databook.  Yes, Moto had a 7-segment decoder 
that was derived from the XC170 ROM and labeled MC4039 (MTTL not 
MRTL).  Other notable MTTL circuits from the same memory array were 
the MC4038 1-of-8 demux, the MC4040 2-of-8 decoder and the MC4041 
Hamming code generator/detector.

On the subject of ganging these things, appnote AN446 has some 
interesting examples.  A binary to 1-of-64 decoder using 9 of the 
ROMS, for example.  But the most relevant is a circuit for driving a 
16-segment alphanumeric display using 5 ROMs driven from 6 bits.

Cheers,
Chuck