3.5 Over-power protection
The power supply will be shutdown and latch off when output power is >
120%~235%.
Current protection must be designed to limit the current to operate within safe
operating conditions.
Over power protection schemes, where only the voltage output that experi-
ences the over power event is shut off, may be adequate to maintain safe
operation of the power supply and the system; however, damage to the
motherboard or other system components may occur. The recommended
over power protection scheme is for the power supply to latch into the shut-
down state. PSU connectors, cables and all other components should not be
melted or damaged prior reaching to the OPP trigger.
3.6 Over Temperature Protection (OTP)
The power supply shall include an over-temperature protection sensor, which
can trip and shut down the power supply at a preset temperature point. Such
an overheated condition is typically the result of internal current overloading
or a cooling fan failure. If the protection circuit is non-latching, then it should
have hysteresis built in to avoid intermittent tripping. PSU connectors, cables
and all other components should not be melted or damaged prior reaching to
the OCP trigger. Test condition AC 115/230V.
4.TIMING
4.1 Signal timing drawing
Figure 2. is a reference for signal timing for main power connector signals and rails.
VAC
PS_ON#
+12 VDC
+5 VDC
Outputs
+3.3 VDC
PWR_OK
PWR_OK Sense level=95% of nominal
06
95%
10%
Figure 2. PS-OK Timing Sequence
T0:AC Turn on time
T1:Power-on time
T2:Rise time
T3:PWR_OK delay
T4:PWR_OK rise time
T5:AC loss to PWR_OK hold-up time
<2S
< 500ms
0.2-20ms
100-150ms
< 10ms
> 16ms