1 Hardware Overview 1.9 Power Supply
1.9 Power Supply
The power supply distributes many different voltages to the system board and performs the
following functions:
1. Input port management
• AC adaptor connection
• Battery pack installation
• The voltage of AC adaptor (both IN and OUT)
2. Power supply internal control
• Battery pack charging status (ON/OFF)
• Controls DC voltage output by AC Adaptor
• Regulates power supply to system components (load and logic circuits)
• Controls circuit breakers in event of a power supply malfunction
3. Management of power to logic circuits
• Controls power to the CPU
• Regulates power supplied to gate arrays
• Controls ON/OFF power
4. Status indicators
• DC IN LED
• Battery LED
5. External device interface
• Monitors I
2
C bus connections through EC/KBC on the system board.
• Transmits the power supply mode.
6. Monitors power output
• Power to systems components (load and logic circuits)
• Battery pack voltage, overvoltage and I/O current
• Battery pack internal temperature
1-26 Satellite A20 Maintenance Manual (960-444)
