jessenator
Well-known member
I'll admit, I haven't done anything especially engineering-y beyond testing in circuits requiring split rail. Eliminating the whine by putting the freq well out of the audible range was my only concern.
1044scpa vs 7662CP vs 7660
- Thread starter Locrian99
- Start date
BrooksBlackhawk
Member
Oh just because I’m dealing with a build that is “whining” and this was one of the more helpful threads on charge pumps here. I noticed the 7662 was mentioned but only briefly and wanted to contribute.
I hadn’t heard of this one, I’m checking it out now, thanks for the suggestion!
BrooksBlackhawk
Member
I totally agree with the frequency being the most important factor with a 9+/9- CP.
For preamp designs, when it comes to higher voltage split rails without whine I’ve defaulted to the big DC>DC converters in SIP packages like the TRACO, MEANWELL RECOM ones.
However for just wanting some headroom and to design in the dual rail bi-polar way for basic pedals, knowing about better CP chips is great! I will absolutely look at the 7660H!
Hello, if you got charge pump whine I suggest to put some 470nF MLCC caps at the input and the output(s) of the charge pump to ground. Works every time for me. Have a look at the aion Straylight and Ember. That's where I first saw people doing it.
jessenator
Well-known member
Can't speak to every person or instance, but looking on the surface, could be price per part? In thru-hole, a 7660S/H is $1.27-$1.40, where a 1054 is $4 on mouser currently.
I guess I don't mind spending the extra on parts where it really counts. I'm certainly not out here buying WIMA film caps or Nichi Gold electrolytics or anything like that. But if you're having problems with noise and wine, which really affects the experience of using the pedal, why not just invest in a quality part?
Elijah-Baley
Active member
Banzai Music has TC1044SEPA, Musikding has TC1044S. I'm not sure if those are the same, maybe I should ask to Musikding. 
Will I have any problem with one of those tow?
I would like to have this chip for the Triangulum Boost, Fortin 33 clone.
Will I have any problem with one of those tow?
I would like to have this chip for the Triangulum Boost, Fortin 33 clone.
SCPA, boosts to 45kBanzai Music has TC1044SEPA, Musikding has TC1044S. I'm not sure if those are the same, maybe I should ask to Musikding.
Will I have any problem with one of those tow?
I would like to have this chip for the Triangulum Boost, Fortin 33 clone.
jessenator
Well-known member
On mobile and don't have the datasets in front of me, but iirc the difference between the SEPA and SCPA is temperature tolerance maximum on the SEPA is wider in both directions. I got samples from Maxim back in 2012(?) and have used both in klones.
But as long as there's an "S" after the "1044" they will boost. But definitely check the datasheet.
But in practice, yeah, keeping it all out of any audio range is preferable.
But as long as there's an "S" after the "1044" they will boost. But definitely check the datasheet.
But in practice, yeah, keeping it all out of any audio range is preferable.
PedalBuilder
Well-known member
Have you tried adding a small capacitor (between 5pF and 20pF) between pins 2 and 7? According to the data sheet, that will increase the oscillator frequency.
On a side note, the price for these things has really jumped. I bought a bunch of them in March 2023 for $1.85 each. It's not even three years later, and they're now $4 each. I can see why people want an alternative.
