Continue to Site

# Voltage doubler

Status
Not open for further replies.

#### chopper

##### New Member
i would like to power up a system which need 3.7V dc and 350mA.

Now, i have an input of 2V,can i use a voltage doubler to power up the system??

If cant,any solution to this problem?

Is the 2V input DC? You'll need a DC to DC boost converter, your power requirements aren't that steep there are plenty of IC's out there that can do it. Linear makes some IC's that should fit your needs. If your input is AC (though I don't see how it can be) you can use a step up transformer and then a bridge rectifier, but at those voltages it's going tobe very inefficient. A good DC-DC boost converter will be 80% or better efficient.

It's theoretically possible, but down at 2V it's hard to get anything to work efficiently.

A good DC-DC boost converter will be 80% or better efficient.
I would hazard a guess that there are no IC boost regs that can hold 80% efficiency boosting 2v (0.6A) up to 3.7V @ 350 mA. The peak currents on the 2V supply would go through the switches. Like I said, it's theoretically possible but I think the efficiency would be pretty bad. 60% would actually be pretty good for this. I believe Maxim has the biggest selection of low voltage boost ICs.

Last edited:
i forgot to mention,the input is 2V ac

i forgot to mention,the input is 2V ac
So a bridge rectifier will get you 2.8 Volts DC and you will still need a low voltage DC-DC converter with all the same problems mentioned by bountyhunter. Where is the cockamamie requiremnt coming from?

So how about a 1:1.5 stepup transformer that gets you to 3VAC, a bridge rectifier gets you 4.24VDC and a 3-terminal LDO that brings it back to 3.7VDC -- simple and straightforward - eh?

Last edited:
Two half wave rectifiers on opposite half cycles will get him 5V with schottky diodes.

Mike.

Two half wave rectifiers on opposite half cycles will get him 5V with schottky diodes.

Mike.
A voltage doubler would also work, and would provide +5V or -5V referred to one of the AC input lines.

The one I'm thinking of gives ±2.5V either side of one of the AC lines. See attached.

Mike.

#### Attachments

• Doubler.png
4.8 KB · Views: 337
Status
Not open for further replies.

Replies
8
Views
3K
Replies
6
Views
924
Replies
16
Views
4K
Replies
8
Views
3K
Replies
20
Views
5K