Cooler Master Silent Pro M 600 W Power Supply Review

Secondary Analysis

This power supply has five Schottky rectifiers on its secondary.

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. Just as an exercise, we can assume a typical duty cycle of 30%.

The +12 V output is produced by three 40CPQ060 Schottky rectifiers, each one supporting up to 40 A (20 A per internal diode at 120° C, 0.49 V maximum voltage drop). Two of them are used for the “freewheeling” part of the rectification, while one use used for the direct rectification part. This way we have a maximum theoretical current of 57 A or 686 W for the +12 V output.

The +5 V output is produced by one STPS60L45CW Schottky rectifier, which is capable of delivering up to 60 A (30 A per internal diode at 135° C, 0.50 V maximum voltage drop), giving us a maximum theoretical current of 43 A or 214 W for the +5 V output.

The +3.3 V output is produced by another STPS60L45CW Schottky rectifier, giving us a maximum theoretical current of 43 A or 141 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 12: +3.3 V, +5 V and +12 V rectifiers.

The outputs are monitored by a PS223 integrated circuit, which supports over voltage (OVP), under voltage (UVP), over current (OCP) and over temperature (OTP) protections. Over temperature protection is really enabled, since we could clearly see two thermal sensors on the secondary heatsink (power supplies with this protection usually need two sensors, one for controlling the speed of the fan and another for controlling the over temperature protection).

Figure 13: Monitoring integrated circuit.

But what is unique about this unit is the presence of an additional protection circuit on the modular cabling system (see Figure 14), controlled by an LM339 voltage comparator.

Figure 14: Monitoring circuit on the modular cabling system.

All capacitors from the secondary are from Teapo.