Power Supply Assembly; Table 7-1. Power Supplya - Compaq EN Series Technical Reference Manual

Chapter 7 Power and Signal Distribution

POWER SUPPLY ASSEMBLY

7.2.1
The power supply assembly is contained in a single unit that features a selectable input voltage:
90-132 VAC and 180-264 VAC. The power supply assembly provides +3.3 VDC, +5 VDC, -5
VDC, +12 VDC, and -12 VDC potentials for the system board, expansion board(s), and installed
drives. These voltages are controlled through the power button on the front panel of the system
unit. Pressing and releasing the power button results in system board logic asserting the PS On
signal, which activates the power supply assembly.
The power supply also produces an auxiliary voltage (+5 AUX). The +5 AUX voltage is used for
powering the power button and other logic required for wake-up operation and is produced as
long as the unit is plugged into a live AC outlet.
NOTE: Minimum loading requirements for the power supply must be met at all times to
ensure normal operation and to meet specifications.
Table 7-1 shows the specifications for the power supply.
Table 7–1. Power Supply Assembly Specifications
Parameter
Input Line Voltage:
110 VAC Setting
220 VAC Setting
Line Frequency
Steady State Input (VAC) Current:
+3.3 VDC Output
+5 VDC Output
-5 VDC Output
+5 AUX Output
+12 VDC Output
-12 VDC Output
NOTES:
[1] Minimum loading requirements must be met at all times to ensure normal operation
and specification compliance.
[2] Surge duration no longer than 10 seconds and +12 tolerance +/- 10%.
The power supply assembly contains a fan that can be shut down by the Fan Off signal, which is
asserted from the system board logic during sleep (suspend) states. The power supply can
override the Fan Off signal if the temperature in the power supply assembly is too high.
7-2 Compaq Deskpro EN Series of Personal Computers
Desktop and Minitower Form Factors
Table 7-1.
Power Supply Assembly Specifications
(P/N 334112-xxx)
Range/ Min. Current
Tolerance Loading [1]
90 - 132 VAC --
180-264 VAC --
47 - 63 Hz --
-- --
+/- 1% 1.40 A
+/- 5 % 1.40 A
+/- 10 % 0.00 A
+/- 5 % 0.10 A
+/- 5 % 0.07 A
+/- 10 % 0.00 A
Third Edition - September 1998
Max. Surge
Current Current [2]
-- --
-- --
-- --
5.50 A --
10.0 A 10.0 A
25.0 A 25.0 A
0.15 A 0.15 A
2.00 A 2.00 A
4.50 A 7.00 A
0.15 A 0.15 A
Max.
Ripple
--
--
--
--
50 mV
50 mV
100 mV
50 mV
120 mV
200 mV