ICL7660SCPAZ vs TC1044SCPA

[Paul.Ruby]

Gotcha. I have a handful of 7660SCPAZ and 1044SCPA, so I'm mostly trying to figure out when to use one or the other (or something completely different, like the LT1054CP). If buying new parts, the LT1054IP is about two bucks a pop at Mouser and seems like it would be a low-noise drop-in for any of these situations since it can replace the 1044 and 7660 as-is. Maybe it would be worthwhile to just stick with those..? Dunno.

I haven't encountered many instances where an LT1054 is explicitly mentioned. I came across this, but it looks like pins 1 & 8 are already bridged... Seems like in this case, I can use either of the ones I have without adding a jumper..?
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Pin 1 on the 1054 should not be shorted to pin 8. Should be left unconnected. But they should be shorted using 1044S or 7660S. There sure are a lot of variations of these things...

 

[Ginsly]

Pin 1 on the 1054 should not be shorted to pin 8. Should be left unconnected. But they should be shorted using 1044S or 7660S. There sure are a lot of variations of these things...

Huh... it sure looks like 1 & 8 are connected in that Ge Fuzzrite I posted where the circuit is expecting a 1054... It's from Aion's schematic, fwiw. Thanks for the insight, I'm JUST entering the world of ICs and it can be a bit confusing!

 

[Robert]

Pin 1 on the 1054 should not be shorted to pin 8.

LT has confirmed that connecting pin 1 and 8 on the LT1054 has no negative impact so some folks just connect them to make the PCB compatible with more charge pumps.

If I recall, on the 1054 pin 1 is a shutdown pin that has to be pulled low to turn off the oscillator, which is why connecting it to VCC has no effect.

 

[Ginsly]

LT has confirmed that connecting pin 1 and 8 on the LT1054 has no negative impact so some folks just connect them to make the PCB compatible with more charge pumps.

If I recall, on the 1054 pin 1 is a shutdown pin that has to be pulled low to turn off the oscillator, which is why connecting it to VCC has no effect.

Very good to know! Thanks Robert! My guess is that it's connected on certain "1054-centric pcbs" just in case someone uses a 7660s or 1044s, which require 1 & 8 to be connected.