ICL7660SCPA bipolar supply? instead of MAX1044

bryantabuteau · February 27, 2005, 11:34:14 PM

Hi, I can't get a hold of the MAX1044 chip until I do an order to small bear, so thought I'd look around at ICs that are available in my country.
The ICL7660SCPA looks like it would do the job fine, and the switching goes over 30khz, so noise shouldn't be a problem. Has anybody used these ICs to generate +9v and -9v bipolar supplies for their pedals, and if so, is it an easy implementation? anyone have any schematics? or should I just wait until I have enough money to do a large order to small bear...

zachary vex · February 27, 2005, 11:51:06 PM

it's the same pinout as the max1044. use the same schematic.

STOMPmole · February 28, 2005, 12:41:26 AM

I've been substituting the TC1044SCPA with good results. As an added bonus it can withstand a higher input voltage than the MAX1044 and is inexpensive ($0.95 at Mouser). The Mouser part number is 579-TC1044SCPA.

bryantabuteau · February 28, 2005, 05:05:11 AM

rockin, thanks guys.

zachary vex · February 28, 2005, 06:37:12 AM

Quote from: STOMPmoleI've been substituting the TC1044SCPA with good results. As an added bonus it can withstand a higher input voltage than the MAX1044 and is inexpensive ($0.95 at Mouser). The Mouser part number is 579-TC1044SCPA.

wow, how'd you find that? it's not even in the catalog yet! 8^)

col · February 28, 2005, 07:11:21 AM

Just built a woody with an ICL7660SCPA I got from www.rapidelectonics.co.uk and it works fine. I measured the voltages an it was slightly less of a - than +. I attached pin 1 ti +9v to increase the speed out ouf the audio range as shown on the spec sheet for the chip.

zachary vex · February 28, 2005, 07:25:02 AM

i've found with every one of these chips there's a very slight loss of voltage for negative. for example, with 5.02 volts in, i generally get -4.95 volts out... but who cares! it's rock and roll, baby! 8^)

col · February 28, 2005, 07:27:51 AM

I agree, if it works don't ask questions just get on with it and enjoy!

Life is difficult enough!

STOMPmole · February 28, 2005, 11:47:03 PM

"wow, how'd you find that? it's not even in the catalog yet! 8^)"

I was searching for the MAX1044...I thought at one point Mouser carried it but for whatever reason I don't see it anymore. Anyway, it's a good thing I didn't find it because the TC1044SCPA seems to work great, is dirt-cheap, and has a little more headroom for the input voltage in case I am (or someone else) is using a poorly regulated power supply. I sub'd the TC1044SCPA in my Neutron and it's working well so far.

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ICL7660SCPA bipolar supply? instead of MAX1044