Datasheet

The PowerBoost 500 (http://adafru.it/dFq) has at the heart a TPS61090 boost converter from

TI (http://adafru.it/duQ). This boost converter chip has some really nice extras such as low

battery detection, 2A internal switch, synchronous conversion, excellent efficiency, and

700KHz high-frequency operation. Check out these specs!

Synchronous operation means you can disconnect the output completely by

connecting the ENable pin to ground. This will completely turn off the output

2A internal switch (~2.5A peak limiting) means you can get 500mA+ fro m as low

as 1.8V, 750mA+ fro m 2 NiMH or Alkaline batteries, and at least 1000mA fro m

a 3.7V LiPoly/LiIon battery or 3 NiMH/Alkalines.

Low battery indicator LED lights up red when the voltage dips below 3.2V, optimized

for the most common usage of LiPo/LiIon battery usage

Onboard 500mA charge-rate 'iOS' data resistors. Solder in the USB connector and you

can plug in any iPhone or iPod for 500mA charge rate. Not suggested for iPad (which

really needs 1A charge rate).

Full breakout for battery in, control pins and power out

90%+ operating efficiency in most cases (see datasheet for efficiency graphs), and

low quiescent current: 5mA when enabled and power LED is on, 20uA when disabled

(power and low batt LED are off)