Power Supply - Toshiba Tecra A6 Maintenance Manual

1.5 Power Supply

1.5 Power Supply
This specification defines the performance and characteristics of the 75W AC adapter power
supply. It supplies a constant voltage 15V output source for Tecra A6 series notebook computer.
A/D conversion
• The EC uses 10-bit sampling for A/D conversion to determine the following values:
– Battery and temperature
AC adaptor and battery check
• The EC checks the following by A/D converted values:
– Battery installed
• The EC checks the following by GPIO values:
– AC adaptor connected
Abnormal check
• The EC determines whether the condition is abnormal, and if so, stores an error
code into the error register.
Input port management
• The EC monitors the following input signal status:
– System power ON/OFF status
– Direct CD power ON/OFF status
Beep and LED control
• Beep is caused by the low battery status.
• The EC controls the following two kinds of LED
– DC IN LED (one color: green)
• Green: indicates AC adaptor is connected
– Battery LED (two colors: orange and green)
• Green solid: The battery is fully charged.
• Orange: The computer is quick-charging the battery / the battery is low.
Power ON/OFF sequence
• When power is turned on or off, the EC starts the power on or off sequence.
– SQ0-4: power ON sequence
– SQ5-B: power OFF sequence
Tecra A6 Series Maintenance Manual
1 Hardware Overview
[CONFIDENTIAL]
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