SparkFun Forums

[roach]

I'm considering the Sparkfun OLED display for a battery-powered mp3 player. I'll be using a pretty small LiPoly 3.6V battery (330mAh), and I'm concerned that the 12V booster supply required for the OLED display will shorten the battery life.

How do these boost supplies work, and what will be the impact on battery life?

[edit]: Okay, that was a little vague. My main concern is that the booster will suck additional current from the battery, thereby increasing the discharge rate. Is there anything I can do to improve this (besides turning off the OLED, which I'm already planning to do).

Also, my understanding is that this 12V supply is used to drive the actual LEDs in the display, not the controller. If I dim the brightness of the display to zero (using the relevant SSD1339 commends), rather than turning it "off", that should save power, right?

[SOI_Sentinel]

Probably. Your current draw would be to take the power required by the backlight, divide by the boost converter's efficiency, and then divide by your pack nominal voltage. (3.7 normally for Lipo)

Note, I don't know much about OLED displays, but I thought they were self-illuminating, no LED's...

Theory:
So, let's say, it's 50ma at 12V. So... 0.6W. 80% conversion efficiency shows 0.75W from the battery. Now, that's 203mA at 3.3V. A bit much! I suspect you're looking at 10mA draw for the LEDs, however. They're probably rated at 12V because the LEDs are daisy chained.

Lowering the display brightness will lengthen the battery life, yes. The controller probably PWMs the lighting FET control.