Apple MC561LL/A, MD772LL/A Power Supply, Power Requirements for Expansion Cards and Peripherals

ÂÂ Total harmonic distortion + noise: Less than -60 dB (0.1 percent)

ÂÂ Frequency response: 100 Hz to 8.2 kHz, +0.5 dB/-3 dB

Power Supply

AC line input

ÂÂ Voltage ranges: 100–240 V alternating current (AC)

ÂÂ Current: Maximum of 12 A (low voltage range) or 5 A (high voltage range)

ÂÂ Frequency: 50–60 Hz single phase

Power Requirements for Expansion Cards and Peripherals

Expansion cards

Combined maximum power consumption for all four PCI Express slots should not exceed 300 watts (W).

USB devices

Each of the computer’s built-in USB ports is allotted 500 mA.

FireWire devices

The computer can provide up to 28 W total to the FireWire ports.

System Clock and Battery

Your computer has CMOS custom circuitry with a long-life battery.

Battery

Use a 3-volt, BR 2032 lithium coin cell replacement battery (see “Replacing the Internal Backup Battery” on page 79).

112Chapter 5   What’s Under the Hood