-- Fryode Electronics is proud to bring you this awesomeness --
Qty: 5
-- Warning: These sell fast in big bursts. Grab if you can, while you can. --
( Best Offer is intended for large-quantity purchases. I like fellow makers, though. What are you working on? )
Texas Instruments PTH08080WAH Switching DC-DC Converter
Variable Output - 0.9VDC to 5.5VDC (adjusted with a single resistor)
Wide Input Voltage Range - 4.5VDC to 18VDC
Switch-Mode conversion
93% Efficiency for less heat
Up to 2.25 Amps Current Output
I can't directly link the datasheet here anymore, but searching for PTH08080WAH pdf will take you to it at TI's site.
Every technical question I have been asked is answered in the datasheet.
Q: How do I set the output voltage?
Please be aware you will need to supply a resistor to set the output voltage. It's connected between pins 2 and 4. The math to find out the ohm value is in the datasheet I've linked from TI.
Open: 0.9VDC
Short: 5.5VDC - incidentally within USB spec, especially with cable voltage drop.
Q: Do I need other parts?
Yes. You will need a capacitor across the input side. A 100 microfarad Tantalum is the go-to, but others are called out specifically in the datasheet. Today's Polymer capacitors are awesome.
A second capacitor of the same value is optional across the output for stabilization of the output voltage.
Working voltage ratings of the capacitors should be at least double the voltage across the + and - at each side. ex: 12V input, 25V rated capacitor.
Why? Harmonics. Square wave. Odd-multiple. Smooth the bounce with a good capacitor. Nichicon, Rubycon, and Nippon Chemicon are solid brands.
Q: What is the pinout?
Pin1 is input, Pin2 is Ground for both input and output, Pin 3 is output.
The Rset resistor is connected between Pin 4 and pin 2.
Pin 5 is an Inhibit pin. If tied to Ground, there will be no output at Pin 3. If left unconnected, output will be present whenever the input voltage is present.
Pin 5 should not be connected to a pull-up of any kind since it has an internal pull-up.
Q: What's the minimum input for the output I want?
The input voltage must be equal to or greater than the output voltage plus 0.9V. If you want a 1.8V output, the input must be at least 2.7VDC.
Shipping is $4.00 for the first quantity and $1.00 each additional quantity. If you need a very large order, the sooner you ask, the better, since there's a lead-time for testing.
Regarding my warranty policy (or lack thereof): I inspect and test every single one of these before I ship them out. They just don't heat up enough to go bad. I have never had a return in the years I've been selling over a thousand of these. Naturally, if something does go wrong, I'll make it right.