icl-7660

[amtech2005]

Just wondering if someone has an equivelant circuit for use in place of ICL-7660 voltage converter chip? Thanks Eugene [email protected]

[_Raz_]

re: ICL7660

Are you looking for a replacement for the Intersil part, or an equivalent circuit using discreet components?

Possible replacements include the Maxim Max1044/ICL7660 and Max660 (higher current).

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1017
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1140

In most of the detector circuits I've seen, the ICL7660 is configured as a voltage doubler and used to derive the +5V rail. I believe the Goldscan IV uses a 555 and a couple of transistors (plus various discreet components) to achieve the same result. The Goldscan IV circuit can be seen in the forum thread below;

http://thunting.com/geotech/forums/s...ad.php4?t=6965

I found the ICL7660 to be too 'weak' for my detector design, and decided on the Texas Instruments PT5049 step-up ISR for that part of my power supply. It provides a good 500mA at +20v, or +8v if referenced to the GND rail (positive battery terminal), which is just about right for feeding the +5v regulators.

It is not a cheap device and it is a bit of an overkill for most detector designs, but it works well.

http://focus.ti.com/docs/prod/folders/print/pt5049.html

[Carl-NC]

You can build a basic voltage doubler with an oscillator (e.g., 555) and 2 diodes + 2 caps.

[amtech2005]

icl7660

Thanks for information , which led me to find this schematic which I believe was used on the 1st barracuda circuit , Thanks again Raz and Carl. Eugene [email protected]

[kt315]

maybe very strange, but ICL7660 in real is not effective converter. it has 4 MOSFET switches and every one gives voltage drop. in result an effectivity is not so hight than a relay ordinary type converter has. if we would dream to get -5 V we really get only -3 V with 7660.

yours