DIYstompboxes.com

DIY Stompboxes => Building your own stompbox => Topic started by: mikeb on April 23, 2004, 10:37:20 PM

Title: Cheapest sources for 1044 charge pumps?
Post by: mikeb on April 23, 2004, 10:37:20 PM
The best price I can find in Australia is Farnell at AUS$9.50 a pop! I know Small Bear does them for US$4 - anyone know of a better price (preferably in Australia, failing that o/s)? This would be for purchases of only 10 at a time.

TIA

Mike
Title: Cheapest sources for 1044 charge pumps?
Post by: vdm on April 23, 2004, 11:49:39 PM
i dont know about your sample politics... but i got 2 max1044's from maxim in about a week for free, delivered through the normal post to melbourne.

as for where to buy them, i havent seem them cheap anywhere...

trent
Title: Cheapest sources for 1044 charge pumps?
Post by: mikeb on April 24, 2004, 02:31:03 AM
Thanks, but I need these in ongoing small quantities!

Mike
Title: Cheapest sources for 1044 charge pumps?
Post by: smoguzbenjamin on April 24, 2004, 04:07:01 AM
Is there an electronics shop in your area that sells ICs? If so you can ask them to order the ICs for you, probably cheaper than $9 per piece ;)
Title: Cheapest sources for 1044 charge pumps?
Post by: Paul Perry (Frostwave) on April 24, 2004, 05:11:07 AM
Mike, do you really need the 1044? because, the ICL7660 is a lot cheaper & easier to get!
Title: Cheapest sources for 1044 charge pumps?
Post by: mikeb on April 24, 2004, 06:43:42 PM
Hey Paul

I was hoping you might drop in here .... ;) ... yes, I can get the 7660's from Altronics. However, the problem (as you might guess) is the whining in the audio region. The 1044's have the frequency boost pin, whereas the 7660's only have the 'external osc input' in. I would be happy to use 7660s *if* I could use a simple osc circuit to drive this pin, where simple means NOT wasting an entire cmos IC just to use one gate, or NOT using an entire OPAMP - a transistor based solution perhaps? So I guess I need the cheapest source for 1044s OR a 20kHz 5V simple square-wave osc circuit! Failing that I think I'll fall back on using an opamp osc circuit .... :(.

Help?! :?

Mike
Title: Cheapest sources for 1044 charge pumps?
Post by: Paul Perry (Frostwave) on April 24, 2004, 09:12:07 PM
Another vendor to check is Linear Technology, they do a range of "improved" charge pumps. But if a simple square wave would help, then I can't see why not a 7555! unless you have a real space problem, which making something out of transistors can hardly help.
Title: Cheapest sources for 1044 charge pumps?
Post by: mikeb on April 25, 2004, 09:47:22 AM
Thanks Paul - yeah, I have to try and fit a new phaser design into a 1590B, and it's a little tight.

Cheers

Mike
Title: Cheapest sources for 1044 charge pumps?
Post by: Paul Perry (Frostwave) on April 25, 2004, 09:53:29 AM
Quote from: mikebphaser design into a 1590B, and it's a little tight.
Mike

oh well, you can gain a lot by putting the resistors vertical! and the caps surface mount!! :D
Title: Cheapest sources for 1044 charge pumps?
Post by: mikeb on April 25, 2004, 11:33:09 PM
I've tried a few layouts doing that - sometimes it doesn't make much difference as the 'area' is necessary to run traces. Besides, SMT stuff is hard to solder by hand in production quantities.  :(

Mike
Title: Cheapest sources for 1044 charge pumps?
Post by: Paul Perry (Frostwave) on April 26, 2004, 08:23:07 AM
Quote from: mikebsometimes it doesn't make much difference as the 'area' is necessary to run traces. Besides, SMT stuff is hard to solder by hand in production quantities.  :(
Mike

that is certainly true, but putting the surface mount stuff (especially bypass caps) on the 'underneath' of the board can be a help. personally, I *like* big boxes! I guess it might be different had I had a model train set as a child...
Title: Re: Cheapest sources for 1044 charge pumps?
Post by: mnats on April 27, 2004, 07:49:40 AM
Quote from: mikebThe best price I can find in Australia is Farnell at AUS$9.50 a pop! I know Small Bear does them for US$4 - anyone know of a better price (preferably in Australia, failing that o/s)? This would be for purchases of only 10 at a time.

TIA

Mike

Forget Farnell. Futurlec has them for $2.90 USD, has no minimum and will apparently ship from their NSW address. That's only 22 cents more than Digikey which has no Australian presence (but will still ship overseas).
Title: Cheapest sources for 1044 charge pumps?
Post by: Paul Perry (Frostwave) on April 27, 2004, 09:22:42 AM
I suspect that (in Australia) it might be faster to get product from Digikey than from Futurlec, judging from some accounts (search 'futurlec' in Googler Groups).