Help Needed To Modify A Design Please!

James Dexter

Other Parts Discussed in Thread: PMP8817, TPS2561A, TPS2514A, TPS2561, UCC28700, LM5023, UCC24630

We are trying to build a USB charger that uses TI parts and want to modify the PMP8817 reference circuit.

We need to increase the power output to 2.8 - 3.0A (which is OK for the newer TI charging IC's) and have a Quad output version.

I am sure someone has already done something similar or knows how we could go about modifying the existing circuit which is featured here:

www.ti.com/.../PMP8817;tisearch=Search-EN-Everything#2

Thanks in advance....

James :-}

over 8 years ago

0 Kening Gao over 8 years ago

TI__Expert 5900 points

Hi James,
Are your requiring a Four-output converter with 5V/3A for every output?
I would like to know your need first.
Br

0 James Dexter over 8 years ago in reply to Kening Gao

Prodigy 50 points

Hi Kening,

Yes we want to produce a USB charger that outputs 2.8-3A at 5V on 4 channels. The TI Evaluation PCB's (different current output but same principal) work perfectly in our prototype.

We have a design that uses TI devices TPS2514A and TPS2561A for control of the USB voltages for different gadgets which is great.

What we require is the power section to handle the 4 outputs if you can hep please!

Best regards,

James :-}

0 Kening Gao over 8 years ago in reply to James Dexter

TI__Expert 5900 points

Hi James,
Yes, you can use the method of PMP8817 forTPS2523/TPS2561..etc..
There is only one winding in the secondary of transformer to output the power.
However, The total output power for PMP8817 is 20W. What you need is a 60W Power.
For the 60W power, we don't suggest UCC28700. The proper sollution is to use LM5023+UCC24630.

Br

0 James Dexter over 8 years ago in reply to Kening Gao

Prodigy 50 points

So it is OK to use the same transformer size just with a different secondary winding for the output?

0 Kening Gao over 8 years ago in reply to James Dexter

TI__Expert 5900 points

No, i don't think the initial transformer of PMP8817 can output as high as 60W.
You need a bigger transformer. besides that, for this power level, ucc28700 is not fit.

Power management

Power management forum

Help Needed To Modify A Design Please!