3.4 Remote On/Off Control : PSON#
The PSON# signal is required to remotely turn on/off the power supply. PSON# is an active low signal
that turns on the +5V, +3.3V, +12V and -12V power rails. When this signal is not pulled low by the
system, or left open, the outputs (except the +5VSB and V bias) turn off. This signal is pulled to a
standby voltage by a pull-up resistor internal to the power supply.
Signal Type
Accepts an open collector/drain
input from the system. Pull-up to
VSB located in power supply.
NO rewoP woL = #NOSP
FFO rewoP hgiH = #NOSP
Table 6 – PWOK Signal Characteristic
3.5 Efficiency
The efficiency is 80% at full loading condition to help reduce system power consumption at typical
system loading conditions.
.
3.6 +5VSB (Standby)
The +5VSB output is always on (+5V Standby) when AC power is applied and power switch is turned
on.
The +5VSB line is capable of delivering at a maximum of 3A for PC board circuit to operate.
4. Protection
Protection circuits inside the power supply shall cause only the power supply’s main outputs to
shutdown. If the power supply latches off due to a protection circuit tripping, either a AC cycle OFF for
15 sec, or PSON# cycle HIGH for 1 sec must be able to restart the power supply.
4.1 Over Power Protection
The OPP function shall work at 110%~170% of rating of output power, then all outputs shut down in a
latch off mode. The latch shall be cleared by toggling the PSON# signal or by cycling the AC power.
The power supply shall not be damaged from repeated power cycling in this condition.
4.2 Over Voltage Protection
Each hot swap module has respective OVP circuit. Once any power supply module shut down in a latch off
mode while the output voltage exceeds the over voltage limit shown in Table 7, the other modules should
deliver the sufficient power to the device continually.
Voltage Minimum Maximum Shutdown Mode
+12V +13.3V +14.5V Latch Off
5VSB +5.7V +6.5V Auto recovery
Table 7 –Over Voltage protection
4.3 Over Current Protection
The power supply should contain the OCP function on each hot swap module. The power supply should be
