Intel SC5299WS User Manual

Residual voltage at the power supply outputs for no load condition do not exceed 100mV when 
AC voltage is applied and the PSON# signal is de-asserted. 

2.4.3.8 

Soft Start Requirements 

The power supply contains a control circuit, which 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 5VSB but the turn on/off is 
monotonic. 

2.4.4 

Protection Circuits 

Protection circuits inside the cage (and the power supply) cause the power supply’s main +12V 
output to shut down, thereby forcing the remaining three outputs on the cage to shut down. If 
the power supply latches off due to a protection circuit tripping, an AC cycle OFF for 15 sec min 
and a PSON

#

 cycle HIGH for 1 second will reset the power supply and the PDB. 

2.4.4.1 

Over-current Protection (OCP)/240VA Protection 

Each DC/DC converter output on the cage has individual OCP circuits. The PS+cage combo will 
shutdown and latch off after an over-current condition occurs. This latch is cleared by toggling 
the PSON

#

 signal or by an AC power interruption. The values are measured at the PDB harness 

connectors. The DC/DC converters are not damaged from repeated power cycling in this 
condition. The +12V output from the power supply is divided on the PDB into 5 channels and 
each is limited to 240VA of power except for +12V5 (+12V5 is not user accessible). There are 
current sensors and limit circuits available to shut down the entire PS+PDB combo if the limit is 
exceeded. The over-current limits are listed in the following table.  

Output Voltage 

MIN OCP Trip Limits 

MAX OCP Trip Limits  

+3.3V  

110% min (= 26.4A min) 

150% max (= 36A max) 

+5V 

110% min (= 33A min) 

150% max (= 45A max) 

-12V 0.625A  2.0A 

 

+12V1 18A  20Amax 

+12V2 18A  20Amax 

+12V3 18A  20A 

max 

+12V4 18A  20A 

max 

+5VSB 

 See the Power Supply specification for details.