Power Supply Board - Toshiba T4500 User Manual

1.8

Power Supply Board

The power supply board supplies five kinds of voltages to the T4500/T4600 Family system board.
The T4500/T4600 Family power supply board has one microprocessor and it operates at 500 KHz
(power off) or 20 MHz (power on).
The power supply board performs the following functions:
1. Determines if the AC adapter or battery is connected to the computer.
2. Detects DC output and circuit malfunctions.
3. Controls the LED indicator and speaker.
4. Controls the Battery capacity icon, Power on icon and AC adapter icon on the status indica-
tor panel.
5. Turns the battery charging system on and off and detects a fully charged battery.
6. Determines if the power can be turned on and off.
7. Provides more accurate detection of a low battery.
8. Calculates the remaining battery capacity.
The power supply board output rating is specified in Table 1-7.
Use for
System logic, FDD, HDD
RS-232-C, Flash ROM
Display
RAM, CPU
RS-232-C
1-18
Table 1-7 Power Supply Board Output Rating
DC
Name voltage
VCC +5
12V +12
DSPV +7.5 to +23
B3V +3.3
M12V –7 to –12.6
Regulation
tolerance
(V) (%)
±5
±5
–
±5
–
Maximum
current Ripple
(mA) (mV)
2,600 100
120 240
7W –
755 66
10 –