DC-ATX-5.0

DC-ATX-5.0 has changed the power structure compared to the 4.0 board, increased the input voltage range, increased the 5V output power, added POK signal output, and added an aluminum substrate PCB as a heat dissipation shell design to increase heat dissipation, aesthetics, and protect components. 

12V power supply is output by independent DC-DC conversion

5VSB power supply is output by independent DC-DC conversion

The 5V power supply is controlled by PMOS and the 5VSB power output

3.3V power supply takes power from 12V power supply and independent DC-DC conversion output

5VSB power-on default output

12V 5V 3.3V is controlled by pulling the PON pin low to turn on

The POK voltage is output from the 5V voltage through the RC delay circuit

All the voltages mentioned above are just for convenience. The actual designed output voltage is slightly higher than the nominal voltage to ensure that it can still be within the ATX specification voltage after wire loss during high-power output.

Actual design output voltage: 12.5V 5.2V 3.4V are all within the +-5% range of ATX output

The total design output limit power is 500W (420+60+20W). During production, the PCB windows should be stacked with tin or buried copper as much as possible to meet the high power output.

The actual measured output power reached the nominal output except for 12V which did not reach the nominal due to inductor rollover. For safety and heat dissipation considerations, it is recommended to leave a certain amount of redundancy for daily use (CPU+GUP<300W/5V<50W/3.3V<12W) use   

Since there is no cannon fodder computer for actual testing, please use it with caution. I will not be responsible for burning the computer.

Key points of rollover:

The inductor I wound myself is really rubbish. The 12V output of the inductor I bought is not as big as the DC-ATX4.0 version. When the output reaches 230W, it collapses and keeps whining. I need to buy some better inductors later and replace them.

The POK signal was originally converted from the PG signal generated by the SY8368 chip. However, the chip specification was not written very clearly, so it was hard to draw, resulting in no output and overturning in the actual test of the board. It has been changed to 5V RC delayed output.