Antec VP350 Power Supply Review

Secondary Analysis

The Antec VP350 uses a regular design in its secondary, with Schottky rectifiers.

The maximum theoretical current that each line can deliver is given by the formula I / (1 – D) where D is the duty cycle used and I is the maximum current supported by the rectifying diode. As an exercise, we can assume a duty cycle of 30 percent.

The +12 V output uses two SBR20A100CT Schottky rectifiers (20 A, 10 A per internal diode at 150° C, 0.85 V maximum voltage drop). This gives us a maximum theoretical current of 29 A or 343 W for the +12 V output.

The +5 V output uses two MBR2045CTG Schottky rectifiers (20 A, 10 A per internal diode at 165° C, 0.84 V maximum voltage drop). This gives us a maximum theoretical current of 29 A or 143 W for the +5 V output.

The +3.3 V output uses one STPS3045CT Schottky rectifier (30 A, 15 A per internal diode at 155° C, 0.84 V maximum voltage drop). This gives us a maximum theoretical current of 21 A or 71 W for the +3.3 V output.

Figure 13: The -12 V voltage regulator and the +3.3 V, +5 V, and +12 V rectifiers

This power supply uses a DWA106N161 monitoring integrated circuit. Unfortunately, we couldn’t find its datasheet, so we can’t comment on the protections this power supply really has. Additionally, this unit has an AS393 voltage comparator, which is equivalent to the famous LM393.

Figure 14: Monitoring circuit

The electrolytic capacitors that filter the outputs are from Taicon and labeled at 105° C, as usual.