PXA250 and PXA210 Applications Processors Design Guide 8-21
Power and Clocking
• Provide power gating switches for the CF, LCD, backlight, RS-232, MMC, Radio, and audio
amplifier subsystems
• Provide a high-efficiency 5.5 V supply rail for LCD and other devices
• Provide a high-efficiency 3.3 V supply rail for I/O and general system power
• Provide a high-efficiency 0.8 – 1.3 V Core/PLL supply for the microprocessor
• Provide separate, clean power rails for the LCD and Audio subsystems
• A small, low-cost, low-heat dissipation pulse-charge method for the battery
8.7.1.1 Power System Configuration
The example form factor reference design power system design is described in Figure 8-5,
“Example Form Factor Reference Design Power System Design” on page 8-22. Note that there are
four main power rails in the system:
• 3.3 V I/O power
• 0.8-1.3 V Core power
• 1.3 V PLL power
• 5.5 V power
