TiVECO TVPS450 Power Supply Review

Secondary Analysis

The TiVECO TVPS450 uses a regular design in its secondary, with Schottky rectifiers.

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 one GMR30H60C Schottky rectifier (30 A, 15 A per internal diode at 25° C, 0.75 V maximum voltage drop), which gives us a maximum theoretical current of 21 A or 257 W for this output.

The +5 V output uses one PBYR3045WT Schottky rectifier (30 A, 15 A per internal diode at 124° C, 0.76 V maximum voltage drop), which gives us a maximum theoretical current of 21 A or 107 W for this output.

The +3.3 V output uses one S16C40C Schottky rectifier (16 A, 8 A per internal diode at 100° C, 0.70 V maximum voltage drop), which gives us a maximum theoretical current of 11 A or 38 W for this output.

Figure 13: The +12 V, +5 V, and +3.3 V rectifiers

This power supply uses an LP-7510 monitoring integrated circuit, which supports only over voltage (OVP) and under voltage (UVP) protections.

Figure 14: Monitoring circuit

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