Soft Starting; Zero Load Stability Requirements; Timing Requirements; Table 122: Output Voltage Timing - Intel SE7520JR2 Technical Manual

Intel® Server Board SE7520JR2
8.2.11

Soft Starting

The power supply shall contain control circuit that provides monotonic soft start for its outputs
without overstress of the AC line or any power supply components at any specified AC line or
load conditions. There is no requirement for rise time on the 5V Standby but the turn on/off shall
be monotonic.
8.2.12

Zero Load Stability Requirements

When the power subsystem operates in a no load condition, it does not need to meet the output
regulation specification, but it must operate without any tripping of over-voltage or other fault
circuitry. When the power subsystem is subsequently loaded, it must begin to regulate and
source current without fault. Each output voltage may not be internally diode isolated. At the
same time failure in the primary side of one power supply doesn't cause the other to shut down.
8.2.13

Timing Requirements

These are the timing requirements for the power supply operation. The output voltages must
rise from 10% to within regulation limits (T
allowed to rise from 1.0 to 70ms. The +3.3V, +5V and +12V output voltages should start to rise
approximately at the same time. All outputs must rise monotonically. The +5V output needs
to be greater than the +3.3V output during any point of the voltage rise. The +5V output must
never be greater than the +3.3V output by more than 2.25V. Each output voltage shall reach
regulation within 50ms (T
voltage shall fall out of regulation within 400msec (T
following figures show the timing requirements for the power supply being turned on and off via
the AC input, with PSON held low and the PSON signal, with the AC input applied.
Item
T Output voltage rise time from each main output.
vout_rise
T All main outputs must be within regulation of each
vout_on
other within this time.
T All main outputs must leave regulation within this
vout_off
time.
Note:
The 5VSB output voltage rise time shall be from 1.0ms to 25.0ms
Revision 1.0
vout_rise
) of each other during turn on of the power supply. Each output
vout_on

Table 122: Output Voltage Timing

Description
C78844-002
Design and Environmental Specifications
) within 5 to 70ms, except for 5VSB - it is
) of each other during turn off. The
vout_off
Minimum
5.0 *
Maximum Units
70 * msec
50 msec
msec
400
209