Enermax NAXN 80+ 600 W Power Supply Review

Secondary Analysis

The Enermax NAXN 80+ 600 W has seven Schottky rectifiers attached to the secondary heatsink.

The maximum theoretical current 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 four SBR30A60CT Schottky rectifiers (30 A, 15 A per internal diode at 110°, 0.60 V maximum voltage drop), giving us a maximum theoretical current of 86 A or 1,029 W for this output.

The +5 V output uses two SBR30U30CT Schottky rectifiers (30 A, 15 A per internal diode at 140° C, 0.54 V maximum voltage drop), giving us a maximum theoretical current of 43 A or 214 W for this output.

The +3.3 V output uses one STPS4045CW Schottky rectifier (40 A, 20 A per internal diode at 150° C, 0.94 V maximum voltage drop), giving us a maximum theoretical current of 29 A or 94 W for this output.

Figure 14: The +12 V, +5 V, and +3.3 V rectifiers

This power supply uses an ST9S429 monitoring integrated circuit, which apparently is a rebranded S3515. This chip supports over voltage (OVP), under voltage (UDP), and over current (OCP) protections. There are two +12 V OCP channels, matching the number of +12 V rails advertised by the manufacturer.

Figure 15: Monitoring circuit

The electrolytic capacitors available in the secondary are from Teapo and Samxon and labeled at 105° C.