Standby Current Requirements - Intel D845PEBT2 Specification

Intel Desktop Board D845PEBT2 Technical Product Specification

2.11.3 Standby Current Requirements

CAUTION
If the standby current necessary to support multiple wake events from the PCI and/or USB buses
exceeds power supply capacity, the Desktop Board D845PEBT2 may lose register settings stored
in memory, etc. Calculate the standby current requirements using the steps described below.
Power supplies used with the Desktop Board D845PEBT2 must be able to provide enough standby
current to support the Instantly Available PC (ACPI S3 sleep state) configuration as outlined in
Table 56 below.
Values are determined by specifications such as PCI 2.2. Actual measured values may vary.
To estimate the amount of standby current required for a particular system configuration, standby
current requirements of all installed components must be added to determine the total standby
current requirement. Refer to the descriptions in Table 56 and review the following steps.
1. Note the total Desktop Board D845PEBT2 standby current requirement.
2. Add to that the total PS/2 port standby current requirement if a wake-enabled device is
connected.
3. Add, from the PCI 2.2 slots (wake enabled) row, the total number of wake-enabled devices
installed (PCI and AGP) and multiply by the standby current requirement.
4. Add, from the PCI 2.2 slots (nonwake enabled) row, the total number of wake-enabled devices
installed (PCI and AGP) and multiply by the standby current requirement.
5. Add all additional wake-enabled devices' and nonwake-enabled devices' standby current
requirements as applicable.
6. Add all the required current totals from steps 1 through 5 to determine the total estimated
standby current power supply requirement.
Table 56.

Standby Current Requirements

Instantly Available PC Current
Support (Estimated for
Integrated Board Components)
Instantly Available PC Stand-by
Current Support
•
Estimated for add-on
components
•
Add to Instantly Available
PC total current
requirement
(See instructions above)
Note: Dependent upon system configuration
80
Description
Total for Desktop Board
D845PEBT2
(Note)
PS/2 ports
PCI 2.2 slots (wake enabled)
PCI 2.2 slots (nonwake enabled)
(Note)
CNR
(Note)
USB ports
Standby Current
Requirements (mA)
220
345
375
80
375
500