Phytec phyCORE-PXA255, Hardware Manual

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Power Supply
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PHYTEC Meßtechnik GmbH 2004 L-657e_0
15
4 Power Supply System
The Development Board functions with a supply voltage of 8 VDC to
24 VDC. The on-board voltage converters generate all supply
voltages required for the components on the Development Board, the
Expansion Board and the phyCORE-PXA255. The supply voltage can
also be used for the optional battery charger circuitry.
Supply voltage 1: +3.3 V (VCC)
Supply voltage 2: +5 V (DIE and CF card)
Supply voltage 3: +5 V (LCD and inverter)
Supply voltage 1: +3.3 V (VCC)
Nearly all of the components on the Development Board, the
Expansion Board and the phyCORE-PXA255 are powered by VCC
(+3.3 V). The supply voltages for the CompactFlash Card and the
Multimedia Card on the Expansion Board can be switched with the
help of transistors. The voltage converter allows for a maximum
current draw of 2 amps at 3.3 V (+/-5 %). The efficiency of the
converter is over 80 %.
Supply voltage 2: +5 V (IDE and CF card)
The 5 V supply voltage is intended only for the 2.5" hard drive and
the CF card. It can be switched on or off during operation. The
voltage converter allows for a maximum current draw of 2 amps at
5 V (+/- 5 %). The efficiency of the regulator is over 80 %.
Supply voltage 3: +5 V (LCD and inverter)
The inverter for the LCD background lighting is powered by this 5 V
supply voltage. The PXA255 switches the background lighting on and
off or dims it over its PWM0 signal. A linear voltage regulator is used
to generate the 3.3 V LCD logic supply voltage from the 5 V LCD.
The voltage converter allows for a maximum current draw of
1.5 amps at 5 V (+/- 5 %). The efficiency of the regulator is over
80 %.