Intel ATX 3.0, Руководство по конструкции

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Electrical
336521 43
4.5.2 Short Circuit Protection (SCP) – REQUIRED
An output short circuit is defined as any output impedance of less than 0.1 ohms. The
power supply shall shut down and latch off for shorting the +3.3V DC, +5V DC, or
+12V DC rails to return or any other rail. The +12V1 DC and 12V2 DC should have
separate short circuit and over current protection. Shorts between main output rails
and +5VSB shall not cause any damage to the power supply. The power supply shall
either shut down and latch off or fold back for shorting the negative rails. +5VSB must
be capable of being shorted indefinitely. When the short is removed, it is
recommended that the power supply shall recover automatically or by cycling
PS_ON#. Optionally, the power supply may latch off when a +5VSB short circuit event
occurs. The power supply shall be capable of withstanding a continuous short circuit to
the output without damage or overstress to the unit (for example, to components,
PCB traces, and connectors) under the input conditions specified in Table 4-1 .
4.5.3 No-Load Situation – REQUIRED
Damage or hazardous condition shall not occur with all the DC output connectors
disconnected from the load. The power supply may latch into the shutdown state.
4.5.4 Over Current Protection (OCP) – REQUIRED
Current protection must be designed to limit the current to operate within safe
operating conditions.
Over current protection schemes, where only the voltage output that experiences the
over current 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 current protection scheme is for the
power supply to latch into the shutdown state. PSU connectors, cables and all other
components should not be melted or damaged prior reaching to the OCP trigger.
4.5.5 Over Temperature Protection (OTP) – REQUIRED
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.
4.5.6 Output Bypass – REQUIRED
The output return may be connected to the power supply chassis and will be
connected to the system chassis by the system components.
4.5.7 Separate Current Limit for 12V2 - OPTIONAL
The 12 V rail on the 2x2 power connector should be a separate current limited output
to meet the requirements of UL and EN 62368-1. This only applies if the PSU is trying