Template:FAQ/Questions/on which priniciples is

On which priniciples is power distribution based on Robostix?
The power distribution strategy is based on these principles:


 * 1) The gumstix board needs appropriate V_BATT via the Hirose-60.
 * 2) The on-board chips need appropriately regulated power at both 5V and 3.3V.
 * 3) The Servos have unpredictable current requirements.
 * 4) Devices on the A/D lines will have unpredictable current requirements at 5V-- but need filtering.
 * 5) Devices on the logic-level lines (GPIO,Timers) will have unpredictable current requirements at 5V.
 * 6) Devices on the UART,I2C lines will have low current draw (i.e. &lt;40mA) at 5V.
 * 7) The gumstix needs to have the ability to do a hardware power-cycle on the ATmega128.

The implementation is based on these premises:


 * 1) The gumstix power supply provides at least 5.0V. This ranges up as much as 5% depending on load and up to 1 A.
 * 2) A 5V requirement is actually 5V +/- 0.5V (e.g. ATmega128 &quot;Electrical Characteristics&quot;)
 * 3) The MIC5219-5.0-BM5 has a dropout from 0.010 V to 0.200 V and peak current source of 500mA
 * 4) V(Logic High) for MIC5219-EN pin is 2.0V and can thus be driven by the PXA255 3.3V logic directly (Min Output High is 3.0V)