Corsair CX430 Power Supply Review

Secondary Analysis

The Corsair CX430 has four Schottky rectifiers attached to its 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%.

The +12 V output uses two MBR3045CTP Schottky rectifiers (30 A, 15 A per internal diode at 125° C, 0.65 V maximum voltage drop). This gives us a maximum theoretical current of 43 A or 514 W for the +12 V output.

The +5 V output uses one MBR2545CTG Schottky rectifier (30 A, 15 A per internal diode at 160° C, 0.82 V maximum voltage drop), giving us a maximum theoretical current of 21 A or 107 W for the +5 V output.

The +3.3 V output uses another MBR2545CTG Schottky rectifier, giving us a maximum theoretical current of 21 A or 71 W for the +3.3 V output.

All these numbers are theoretical. The real amount of current/power each output can deliver is limited by other components, especially by the coils used on each output.

Figure 14: +5 V and the two +12 V rectifiers (the +3.3 V rectifier is on the other side of the heatsink)

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, but the manufacturer decided to use only of them, making this unit a single-rail model. 

Figure 15: Monitoring circuit

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