Need Output 3.3V from input of 1.8V to 2.0V

Discussion in 'General Electronics Chat' started by mpcotuong, Aug 27, 2010.

Aug 26, 2010
170
0
Hi All,

Please help me to make the circuit ouput 3.3V to 5VDC from input 1.8V to 2.V. I have the circuit output only 1.8V but my Nail replay need min 2.9V to work. Please let me know how to solve this problem.

Thanks,
Kevin

2. AMIT_GOHEL Member

Jul 13, 2010
67
7
mpcotuong likes this.

May 11, 2010
241
38
The part for you is TPS60211 from TI.
Very good little charge pump chip.
Very low quiescent and up to 100 mA output.
1.8 to 2.0V is its sweet spot for input voltages.
http://focus.ti.com/docs/prod/folders/print/tps60211.html

Only thing difficult is it's an MSOP so a bit hard to solder.

4. SgtWookie Expert

Jul 17, 2007
22,202
1,793
Without knowing your output current requirements, it will be difficult to make a recommendation.

You should also specify what the input current is, or if battery powered, what the AH or mAH rating of the battery is.

Aug 26, 2010
170
0

Please let me know what is the input and output of your diagram? Why you are using transformer? Is that transformer?

Thanks,
Kevin

Aug 26, 2010
170
0

Kevin

Aug 26, 2010
170
0

I don't know what the output current. But the relay has not take 2.0V. My project output is only 2.0V and need at least 2.9 to 5V to operating the circuit.

Thanks,
Kevin

8. SgtWookie Expert

Jul 17, 2007
22,202
1,793
OK, then.
How much current do you need at 2.9v to 5v?

How much current is available at your project output without it sinking below 2v?

Unless you can tell us what kind of current is available, and what current you require, we cannot make a very good recommendation.

If your current requirement at 2.9v to 5v is low (say, <10mA), something like an ICL7660S may work well for you.

Keep in mind that to get 4v from 2v, you will need more than twice the current from the 2v supply than you can output, as no boost circuit is 100% efficient. Some are very close. About the best you can hope for is 90% efficiency from a typical boost circuit. Many are much less efficient.

9. AMIT_GOHEL Member

Jul 13, 2010
67
7

No u not need to use transformer,i'm talking abt ckt after transformer..

In a pic
Left-input ,Right-output.
At output side voltage will be doubled and fan-out will be half..

mpcotuong likes this.
10. tom66 Senior Member

May 9, 2009
2,613
218
You need an AC input for the voltage doubler to work. The OP said they wanted a DC to DC converter, if I read their post correctly.

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Aug 26, 2010
170
0

I need 100mA output

Thanks,
Kevin

12. SgtWookie Expert

Jul 17, 2007
22,202
1,793
If you need 100mA output at 4v, you will need at least 220mA input at 2v.

Is that available? If not, good luck.

13. AMIT_GOHEL Member

Jul 13, 2010
67
7
hello kevin,

will you tell me what you actualy suppose to do ?
mean to say why you need this conversion ?