For a hobby project I'm trying to power a PIC microcontroller and 4 RGB leds from two AA batteries. I have both the PIC and the circuit shown below being powered by the batteries and the PIC communicates with the PCA9635(for brightness control) through I2C. Since the blue and green leds have a forward voltage of 2.8V and I wanted to ensure that they could stay on as the battery discharges, I added a boost converter (as shown), which is capable of 300ma at 3.3V. The PCA9635 is capable of sinking 25 ma on each input pin and since there are 12 total leds (RGB for each), each rated at 20ma, the total current consumed should be less than the 300ma limit of the boost converter.

![Schematic](https://i.stack.imgur.com/QAcLO.png)

On fresh batteries the circuit works. However, with slightly used batteries, when I begin to turn on LEDs the voltage of the batteries drops sharply causing the PIC to brown out/reset. It seems to me that two AA batteries should be able to source the amount of current required for this. So my questions are:

Is it possible to power everything both without causing a brown out and without using an alternate/extra power source?

What is causing the sharp voltage drop?

Is there a better way to power the 4 RGB leds than using a boost converter?

EDIT:
The actual leds being used are these: <http://www.dialight.com/Product/Details/445022/5988710307F>.