7.4v to 10.2v step-up converter?



I need to convert 7.4v to 10.2v. I have a Li-ion battery pack that outputs 3700 mAh, and a (revision c) gamecube that requires a minimum of 10.2v to function. I would like to power the gamecube using this battery pack, and avoid having to buy more cells and a new protection circut. Can anyone help me make this step-up converter? (Preferably using a TI converter). Thanks!

Picture of 7.4v to 10.2v step-up converter?
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How much current do you need ?
ryguy425425 (author)  steveastrouk6 years ago
The gamecube will draw 21w. Is that what you're looking for?
So say 2.5 A to be on the safe side ?
ryguy425425 (author)  steveastrouk6 years ago
The gamecube powerbrick claims to output 3.25A. I'd imagine I can get away with less though.
Unlikely. The game cube probably requires surge capability, during startup and at other times. I'd suggest you consider mimicking the existing output capability.

Honestly, I don't think a 3.7AHr battery is going to do you much good for the expected load, although if you get a battery pack with more capacity, there are dozens of solutions.

Check digikey.com (as a device search tool if nothing else) Enter "Step up" in the search box. then choose

PMIC - Voltage Regulators - Special Purpose (12 items)
PMIC - Voltage Regulators - Switching DC DC Converters & Controllers (5,532 items)
DC DC Non-Isolated - Linear Regulator Drop-In Replacement (16 items)
DC DC Non-Isolated - Point of Load (POL) (9 items)

and
Eval and Demo Boards and Kits (28 items)
Eval Boards - DC/DC & AC/DC (Off-Line) SMPS (933 items)

pick thru the circuits for the input and output characteristics.
ryguy425425 (author)  seandogue6 years ago
A typical portable gamecube is built with a 5AHr to 6.4AHr battery, although with a revision C gamecube it is usually 14.4v (revisions a and b are usually 7.4). I am on the lower side, but it won't be used on the road a whole lot. Thanks for your help, I think I'll be able to find what I need on digikey now.
Glad to be of assistance (as much as I was). No offense on the negatory comment regarding feasibility, it's just that 370mAhr seems pretty low for the predicted draw.
ryguy425425 (author)  seandogue6 years ago
I've been told that this battery should power the completed project for a little over an hour (although I personally am expecting less). Since I have your attention, I think I've narrowed my search down to there http://search.digikey.com/scripts/DkSearch/dksus.dll (I'm relay hoping that ling works). They all seem to output 120mA and 175 mW. I really don't know how to do the conversions, but that doesn't seem like enough power to me.
Yes, about an hour, but that's the bleeding edge.

I was thinking one of the Linear converters (the company not the technology). There are several that seem to be in your required input/output range, although they will likely need ancillary support (additional inductors, caps, etc.).

Ok, go back to digikey

enter "step up" ion the search filter. Choose
PMIC - Voltage Regulators - Switching DC DC Converters & Controllers (5,532 items)

Now, choose linear as the source (there are two entries, select them both)
(multiple choices by using the ctrl key when selecting)

"apply filters"

Now isolate the output range by including all but the last choice in "Voltage - Output"

"apply filters"

Now, from the type column, select only the "step-down(buck), step-up(boost)" and Step-up (boost) entries.

"apply filters"

There seem to be several choices that might work for you.

My one concern is the switching frequency. I'm not sure what the requirements are in that respect for the gamecube

ryguy425425 (author)  seandogue6 years ago
Thanks again! Now if I can only find a wiring diagram that I can understand I'll be set!
Linear and the other IC mfgs offer suggested circuits at their websites.

As much as it's not a cheap solution, have you considered using one of the canned solutions they offer? There are both end use DC DC converters and "evaluation" units available, although not at the $5-10 range. building dc/dc converters isn't a first order electronics project, and I'm not sure of your qualifications in that area.
ryguy425425 (author)  ryguy4254256 years ago
It looks like I need 1.5A if I am running the gamecube on 12v. I really don't know exactly what I'm looking for.