Boost IC

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Markers
 
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Boost IC

Post by Markers »

I'm currently trying to design a circuit that uses a 3.7v (2300mAh) lipoly battery to power a 9v, 150mAh device. I found a DC boost IC (http://search.digikey.com/scripts/DkSea ... L499ACP-ND) to increase the voltage to the required 9v, but I am not too sure if that will do the job.

The plan is to use the Adafruit USB LiIon/LiPoly charger and connect my boost circuit to the load to power the device. Any input would be greatly appreciated. Thank you.

Snipeye
 
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Re: Boost IC

Post by Snipeye »

Well, that has a maximum current output of 100mA, so no. It won't work. Sorry to burst your bubble, but that's first thing you need - hard to select other components and get stuff up and running until you've got an adequate boost chip selected.

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zener
 
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Re: Boost IC

Post by zener »

Did you mean 150mA or do you really mean 150mAh? If the latter then I am a little confused about what it is. If it is 150mA then are you sure it really draws that much?

Markers
 
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Re: Boost IC

Post by Markers »

I just ordered the device so I guess I can use my multi-meter to measure the current when it arrives. The device is a wireless camera and several people have said a 9v 150mAh battery only lasted an hour. So I guess that IC I found with a 100mA output should be sufficient. I'm a still very new to the DIY electronic scene and I greatly appreciate the time you spent answering my question.

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zener
 
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Re: Boost IC

Post by zener »

It likely draws less than 150mA, though it will depend on what it is doing. The current draw may be somewhat voltage sensitive, so check it throughout its functional supply voltage range.

Snipeye
 
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Re: Boost IC

Post by Snipeye »

The crapping spam...

Anyway, I know that 9v batteries have a lot of internal resistance - they're not good at delivering lots of current at once. I don't have any numbers, but it could be that they're not good at being drawn at a 1C rate, meaning that a 9v battery would deliver power... inefficiently - wasting some to heat. If you're lucky, a 100mA supply MIGHT work.

Markers
 
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Re: Boost IC

Post by Markers »

The camera should be here tomorrow so I'll be able to measure the current when its under load. But just to be on the safe side, I ordered two ICs (100mA and 200mA) from DigiKey.

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