In-Win IP-P300AJ2-0 and IP-P350AJ2-0

The AJ series has but recently appeared on In-Win’s catalogue, but its specs are very similar to those of the A and J models I have described above. It is still the out-dated ATX12V 1.3 standard. So what is the difference between the IP-P300AJ2-0 and the old IW-P300J2-0, for example?

Different output power ratings are the single discrepancy between the IP-P300AJ2-0 and the IP-P350AJ2-0, so I will describe and test them both together. The former PSU comes in the In-Win IW-S506 system case and the latter comes in a box.

These PSUs don’t seem to differ externally from the IW-P430J2-0.

But they are dramatically different on the inside! These PSUs don’t just use another PCB, they feature quite different components. An UC3843AN chip is used as a PWM controller now. The PSU features a single-ended single-transistor converter. That’s not a very popular solution due to the necessity of using 900V transistors (a double supply voltage, i.e. over 600V, is applied to them in this circuit design). The standby source is at last based on an integrated chip with a minimum of accompanying components instead of a handful of discrete components. This Infineon ICE2A0565Z chip is a specialized PWM controller for low-power sources, up to 23W when working in a 220V power grid and up to 13V when working in the universal range of 85-265V, which is quite enough for a PSU’s standby source. A special-purpose chip from Weltrend is used as an output voltage supervisor. These changes are all welcome. In-Win has finally transitioned to using more modern components than in the PSUs described in the previous sections.

Heatsinks punched out of an aluminum bar are used now instead of extrusive heatsinks. They look cheaper but I wouldn’t claim they are inferior to the older ones. Such heatsinks are better suited to receive airflow from above.

The PSUs still don’t have active PFC (a passive PFC device can be installed optionally) and have group voltage regulation.

The junior (300W) model is equipped with these cables and connectors:

• Mainboard cable with a 20+4 connector (35cm long)
• CPU cable with a 4-pin connector (36cm long)
• Cable with two Molex connectors and one floppy mini-plug (25cm+15cm+15cm)
• Cable with two Molex connectors (42cm+15cm)
• Cable with two SATA power connector (40cm+15cm)

The senior model has 5cm longer CPU and mainboard cables and a non-separable 24-pin connector instead of the splittable 20+4 one. An adapter is enclosed with it to connect to older mainboards. The rest of its connectors are the same.

Unfortunately, the PSUs still belong to the out-dated ATX12V 1.3 standard, and the load current of the +12V power rail is not higher than 18A (for comparison: the typical 300W ATX12V 2.0 power supply must provide a current of 22A on that rail; the difference is bigger with PSUs of higher wattage). Otherwise, I have no questions about the specs. All the numbers match each other, and there is no mention of the word “peak”.

The 350W model differs only in the overall wattage because the load currents are the same. I want to remind you about the specifics of power consumption of modern computer systems again. Most of the power they consume comes from the +12V power rail whereas the combined power draw from the +5V and +3.3V rails is not higher than a few dozen watts. So, even if the IP-P300AJ2-0’s 12V rail is loaded fully (216W), there is still 64W left for the +5V and +3.3V rails which is more than enough for a majority of computers this power supply may be installed in. Replacing it with an IP-P350AJ2-0 doesn’t make any difference because you will reach the 216W limit on the +12V rail sooner than you reach an overall output power of at least 300W. This is an example of how the capabilities of a power supply may be limited not by its wattage but by its compliance with an out-dated version of the ATX standard. As a result, there is in fact no practical difference between these two PSUs despite their different wattage.