LT1054 ok for Fatpants and Roadrage?

[hoyager]

Hi there, does anyone know if the LT1054 will work in the fatpants? It has an operating voltage of up to 15v and the osc frequency is from 15khz to 35khz on 3.5v to 15v so I assume when running at 9v the freq will be out of range? Pin 1 on the LT1054 is different to the MAX1044, where it doubles the osc freq range when connected to pin 8 so its out of hearing range.

from the datasheet about pin 1 on the LT1054

"The feedback/shutdown (FB/SD)  terminal has two functions. Pulling FB/SD below the shutdown threshold
(≈ 0.45 V) puts the device into shutdown.

FB/SD also is the inverting input of the LT1054 error amplifier and, as such, can be used to obtain a regulated output voltage."

Will I need to cut the track between pin 1 and 8 on the iC?

Also will it be the same story with the Roadrage boards?

One more thing, I plan to use a roadrage board with this chip which accepts 15v dc to supply bipolar dc for powering a synth module (vcf) and am wondering if someone can confirm if thats going to work?

All signs point to yes but with my noob brain I can't be sure....


This is the cheapest option for me in NZ, smallbear at 1.70 (MAX1044 from futurlec and smallbear are 3.50 and the LTC1044 from futurlec are 3.90)

cheers
Andy

[jkokura]

The TC1044 is also a good option if you can get ahold of one. In batches of ten they're 1 buck US each from Mouser.

Jacob

[hoyager]

The TC1044 doesn't take 15v though, I was hoping to be able to power a synth filter which needs bipolar 15v

[madbean]

I'll have to check the datasheet to see if the layout is compatible for the RR.

[ibodog]

I've used LT1054 in similar designs.  Just bend up pin 1 on the IC so that it isn't connected to anything.

http://www.aronnelson.com/gallery/main.php/v/ibodog/power/positive+ground+fuzz+adapter+vero+verified+v1_0.gif.html

[hoyager]

Ohh, of course, thanks!

layout is the same Brian, just that pin 1 has a different function

[madbean]

F-N A' that's good news! I actually have one of the LT1054 which I wanted to test out. I'm considering it for a few different applications, including another analog delay design with higher voltages/current.

I'll add this info to the Road Rage docs since I'm going to expand on the info in there anyway,

Thanks a bunch, fellas!

[ibodog]

In the Texas Instruments LT1054 data sheet, check out the "Dual-Output Voltage Doubler" schematic in figure 24.  I used that to power a clone of a Carl Martin AC Tone at +/- 17V.

[bigmufffuzzwizz]

I had trouble finding a reasonably priced chip also. Next time i'm gonna check out some bigger distributors or maybe ebay will have some in bulk for cheap.

[hoyager]

Wierd.....

LT1054 from smallbear are now $2.95, no shit...

I swear the longer this order is taking to put together the more its costing.

This is dumb, will have to find somewhere else to get them

[ibodog]

Wierd.....

LT1054 from smallbear are now $2.95, no shit...

Wow, I just looked it up and the last time I got some from Mouser (a while back) they were $1.75 each.  Now up to $3.08 at Mouser!

[madbean]

People must be reading this thread...

[bigmufffuzzwizz]

They are $2.20 from futurlec part #LT1054CN8

Here's another suggestion, possibly a group buy. It would come out to $1.60 a chip for max1044.
http://cgi.ebay.com/100x-MAX1044CPA-MAX1044-maxim-ic-/280538537702?pt=LH_DefaultDomain_0&hash=item4151665ee6