Compaq 164SX Manual De Usuario
2–4
Features
Power Requirements
2.1 Power Requirements
The AlphaPC 164SX motherboard has a total power dissipation of 90 W, excluding
any plug-in PCI and ISA devices. Table 2–3 lists the power requirement for each dc
supply voltage.
any plug-in PCI and ISA devices. Table 2–3 lists the power requirement for each dc
supply voltage.
The power supply must be ATX-compliant.
Caution:
Fan sensor required. The 21164PC microprocessor cooling fan must
drive an RPM indicator signal. If the airflow stops, the sensor on the
motherboard detects that the RPM has stopped, and resets the system.
drive an RPM indicator signal. If the airflow stops, the sensor on the
motherboard detects that the RPM has stopped, and resets the system.
2.2 Environmental Requirements
The 21164PC microprocessor is cooled by a small fan blowing directly into the
chip’s heat sink. The AlphaPC 164SX motherboard is designed to run efficiently by
using only this fan. Additional fans may be necessary depending upon cabinetry and
the requirements of plug-in cards.
chip’s heat sink. The AlphaPC 164SX motherboard is designed to run efficiently by
using only this fan. Additional fans may be necessary depending upon cabinetry and
the requirements of plug-in cards.
The AlphaPC 164SX motherboard is specified to run within the environment listed
in Table 2–4.
in Table 2–4.
1
Values indicated are for an AlphaPC 164SX motherboard with an Alpha 21164PC microprocessor
operating at 400 MHz, with 128MB SDRAM, excluding adapter cards and disk drives.
operating at 400 MHz, with 128MB SDRAM, excluding adapter cards and disk drives.
Table 2–3 Power Supply DC Current Requirements
Voltage/Tolerance
Current
1
+3.3 V dc,
±
5%
5.0 A
+5 V dc,
±
5%
12.0 A
–5 V dc,
±
5%
0.0 A
+12 V dc,
±
5%
1.0 A
–12 V dc,
±
5%
100.0 mA