The +5VSB Power Supply
The +5VSB (a.k.a. standby) power supply is independent of the main power supply, since it is on continuously.
The switching section of the +5VSB power supply uses an AP03N70I MOSFET, which supports up to 3.3 A at 25° C or 2.1 A at 100° C in continuous mode or up to 10 A at 25° C in pulse mode, with a maximum RDS(on) of 3.6 Ω.
The rectification of the +5VSB output is performed by an STPS20L60CT Schottky rectifier, which supports up to 20 A (10 A per internal diode at 140° C, 0.74 V maximum voltage drop).