Secondary Analysis

Instead of using Schottky rectifiers like almost all power supplies Antec TruePower Quattro 850 W uses power MOSFET transistors on its secondary. This is the second power supply we’ve seen using such configuration (the other one was OCZ ProXStream 1000 W).

For rectifying the +12 V output four IRL2203N power MOSFET transistors are used, each one capable of handling up to 82 A at 100º C in continuous mode or up to 400 A in pulse mode (at 25º C). This gives us a maximum theoretical power of almost 4,000 W for the +12 V output, but of course the real capacity will depend on several other factors such as the transformer, the coil, the capacitors, the gauge of the wires and even the width of the printed circuit board traces.

For rectifying the +5 V output two IRL3705Z power MOSFET transistors are used, each one capable of handling up to 61 A at 100º C in continuous mode or up to 340 A in pulse mode (at 25º C). This would give us as maximum theoretical power of 610 W for the +5 V output, but as we already explained the real capacity depends on the other components used.

And for rectifying the +3.3 V output other two IRL3705Z power MOSFET transistors are used, giving a maximum theoretical power of 204.6 W for this line.

The +5VSB output uses a regular Schottky diode pack, SR1060, capable of delivering up to 10 A at 25º C.

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Figure 14: Two +12 V transistors, +5 V transistor, +3.3 V transistor and +5VSB rectifier. The other transistors are on the other side of the heatsink.

This power supply uses a PS223 monitoring integrated circuit, which is in charge of the power supply protections, like OCP (over current protection). OCP was really activated, as we will talk about later. This IC also provides over voltage protection (OVP), under voltage protection (UVP) and over temperature protection (OTP), but not over power protection (OPP).

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Figure 15: PS223 monitoring integrated circuit.

This power supply has two thermal sensors: one for controlling the speed of the fan and one for shutting down the power supply in case of an overheating situation (i.e. OTP, over temperature protection). It is interesting to note that Antec doesn’t list OTP as a feature for this power supply, but the monitoring IC supports this feature and it is connected to a thermal sensor.

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Figure 16: Thermal sensors.

The active PFC electrolytic capacitor is Japanese from Chemi-Con (rated at 105º C) but the secondary capacitors are Taiwanese from Teapo (rated at 105º C).

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