I am looking for an intergrated circuit that would charge a bank of 4 capacitors in parallel and then discharge them in series. I have a 1 volt dc source.
I am afraid that you have to look for a long time for that IC. One volt is not something you can even start affecting a transfer gate or switch with. Unless it is a BJT switch. And that will not work in such an application.
You need to create a higher voltage from 1 V? There is a possibility that a fly-back switcher could do the job.
I agree with Skogs. Low voltage CMOS switches seem to run out of steam at around 1.8V. A single transistor blocking oscillator using a small transformer or pot core would probably do the job, but the efficiency would probably be poor (40%).
I doubt you will find a ready-made chip. Advanced Linear Devices does make some nift zero-threshold MOSFETs that would be useful building blocks for your own design.
Yeah, you're probably not going to find a single chip that does what you want. The Maxim MAX660 will double a voltage (or generate an inverse) with a 100 mA load but is only specified down to 1.2 volts, not quite what you want. If that's good enough, and you only need 50 mA or so, you can cascade a couple of them.
What level of current are you dealing with? Size of capacitor?
There are plenty of circuits that can boost from 1 volt to several volts, but they generally use discrete parts.
If you really need to charge 4 caps in parallel and then connect them in series, I suggest using a low power boost circuit to generate enough voltage to power some MOS devices to do the switching. That way, you can tailor the devices to the power level you require.
Googling [blue]single cell "boost converter"[/blue] gives a number of hits. The highest power I noticed was 5V @ 1A from a single cell using the Linear's LT1308B. 1.0V is right at the bottom of its operating range.
I am not so sure that we are answering the OP's question any more. I was just guessing that he needed to go from 1 V to a higher voltage. But all he asked for was an IC that could charge four capacitor in parallel and then connect them in series. We seem to have lost him.We haven't had any comments from him so far.
Thank You all for your input on this issue. My main objective is to boost the level to 3 volts but have exhausted all resources here at work. we are looking to charge a battery and figured the only possibility would be a pulsed type of a charge by charging the caps in parallel and discharging in series. The power level of the source is in the microwatt range. We have experimented by charging 3 10,000 uf caps in parallel and hitting a switch to series them. I was hoping to do it electronicly.
3.0 / 3.3V are standard voltages for microprocessors. There are numerous ICs which are specifically designed to produce a stable 3.0 or 3.3V from a single cell.
I was sorting out articles I've removed from magazines when one made me recall this eng-tips post for charging capacitors from less than a 1 volt supply.
EDN designs ideas for May 25, 2006 pp 91-92 has a DC-to-DC converter that can operate from voltages as low as 300mV to 1.6 volts. With 475mV input it can suppy 2ma at 5 volts.
