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Advice on Power Integrations reference designs ...

Posted by: Jesper M on Mon, 07/19/2021

Hello PI,

I am looking for some PI reference designs that fulfill these two main requirements:

1. A 100 - 230 VAC to ~ 100 VDC design capable of delivering 150 mA on the 100 VDC side. Should be (very) low noise particularly at higher frequencies (> 50 kHz). High efficiency is also desired but noise level is most important. Maybe this is already the case but it should be current limited (short circuit protected). 

2. A 100 - 230 VAC to 7 - 15 VDC design capable of delivering 500 mA on the 7 - 15 VDC side. Again it should be very low noise particularly at higher frequencies (> 50 kHz). And again short circuit protection is needed.

I would appreciate if you may be able to advice on such two designs preferably including a suggested PCB layout.

Best regards & thanks for help in this,

Jesper Mønsted


Submitted by PI-Cylon on Tue, 08/03/2021

Hi Jesper,

Before I could recommend you some reference designs, I need to ask you a few more questions about your design to clarify things.

1. Is this a single converter design with two outputs or two separate power converter designs?

2. Could you please explain what you mean by low noise? Do you mean low ripple voltage on the output of the design or EMI noise on the input? Do you have a specific spec that you are trying to meet? If you can give a more specific spec (for example, < X dB noise above 50kHz) I can actually see which solutions meet your requirements. In general, PI products are designed for low noise.

3. Could you be more precise about your output specification. How close to 100VDC do you need to be? Is there a specific value in the 7-15VDC range that you are designing for.


In general, your second design for 500mA 7-15VDC is easy to meet using one of our InnoSwitch products, but those are optimized mostly for higher power, 10 Watts and above. TinySwitch is designed for lower power, but it uses a different control method, which may or may not meet your noise requirements (I would be able to tell you once I know more about how much noise is acceptable).

The 100VDC spec is rather unusual because it is also very low power. Once I know more about how much noise is acceptable, I can tell you what designs may work.