Service manual

System Overview 1-67
Figure 1–29 shows the block diagram of the hierarchical switch power supply.
The module converts 48 VDC to the following required outputs:
• -1.7VP at 2.5 amps
• +1.7V at 14 amps
• +2.5V at 7.5 amps
• +3.3VP at 5 amps
• +3.3V at 5.5 amps
• +5.0V at 0.15 amps
• +15V at 0.5 amps
Only one power module is required for the H-switch; the second is redundant
and either module is hot swappable. Other features include the ability to
enable the module remotely, sense the outputs at the delivery point, and assert
DC OK signals. The module also is attached to the I
2
C bus for module history
and revision EEPROM support.
Components on the H-switch are protected from overcurrent and voltage
changes outside set window limits.
LEDs
Vaux Present
(green)
On (normal)
Off
Indicates Vaux present at the module
Vaux not present
+3.3VP OK
(green)
On (normal)
Off
Voltage is within tolerance window
Voltage is outside the tolerance window
+3.3V OK
(green)
On (normal)
Off
Voltage is within tolerance window
Voltage is outside the tolerance window
-1.7VP OK
(green)
On (normal)
Off
Voltage is within tolerance window
Voltage is outside the tolerance window
Internal +5V OK
(green)
On (normal)
Off
Voltage is within tolerance window
Voltage is outside the tolerance window
+1.7V OK
(green)
On (normal)
Off
Voltage is within tolerance window
Voltage is outside the tolerance window
Swap OK
(yellow)
On
Off (normal)
OK to swap out the module (Vaux LED may
be on also)
The module is not ready to swap out
Module OK
(green)
On (normal)
Off
All voltages are within tolerances
At least one voltage is out of tolerance
+2.5V OK
(green)
On (normal)
Off
Voltage is within tolerance window
Voltage is outside the tolerance window