5vdc to 3.8vdc step down

[StealthRT]

Hey all i am in need of some help with stepping down a 5vdc to 3.8vdc so that i can power my phone.

The battery that's powering the phone is rated at 3.8vdc 1730mAh 6.57Whr.

What all would i need in order to step down from the 5vdc to around the 3.8vdc mark?

The USB 5vdc is rated at 5.1vdc 2.1A.

Any help would be great!

 

[CocaCola]

Why not just plug the 5V into the phones charging port, almost all phones are 5V input now on the charging port?

If you want a quick an dirty, use two diodes in series, or use a zener diode configured to fix the voltage, a quick Google search will reveal how...

You could also use a low drop out regulator if you can find a suitable one...