1.5 Power Supply 1 Hardware Overview
[CONFIDENTIAL]Satellite L670/Pro L670 Maintenance Manual
1.5 Power Supply The power supply unit provides constant voltage (19V) for the system board and performs the
following functions:
1. Power input monitor
y Checks whether the AC adapter (DC power supply) is connected to the computer.
y Checks whether the battery pack is connected to the computer.
y Monitors the DC power supply input voltage (AC Adapter output voltage).
2. Power supply's internal control
y Turns on and off the battery pack charging power supply.
y Issues a charging current instruction to the PWM control IC of the battery pack charging
power supply.
y Controls the supply of DC power supply input (AC Adapter output) to the power supply
unit.
y Controls the supply of power to the system block (load/logic circuit side).
y Controls forced shutdown if the power supply malfunctions.
3. Logic circuit control
y Instructs the gate array to enable/disable tuning the power on.
y Controls power-on/off operation.
4. Status display
y Turns on the Power LED (in White).
y Battery indicator (in White or Amber).
y DC-IN indicator (in White)
5. External interface
y Performs communication through the I2C bus (via the internal EC/KBC).
y Transfers the power supply operation mode.