Isolated Multi Output Design
Hello,
I have a couple of questions.
1- Can I use the TOP223Y for a multi isolated power supply.
I can get a transformer with multiple taps that are isolated from each other.
I can make a transformer with main winding, feedback winding and 5 more windings of different voltages.
2- Do you have an application note for this?
My voltages are: 3.3V, Two 5V and Two 15V with different currents.
The total wattage adds to less than 16 watts. using a multiplier of 1.5
for safety I think my usage will be under 24Watts.
Input range is the 85 to 265 VAC.
3- Is this a good selection or I need to use the 45Watt device?
4- Do you know a transformer company that is familiar with your products?
Thank you,
Harry
Comments
Hello Terry,
The Figure1 of the AN-22 shows a NEC2501 coupler.
The NEC2501 does not exist anymore.
The CEL corporation recommended the PS2501-xxxx series as replacement.
There is a good number of products fitting under the PS2501-x number.
I tried to find a suggested gain for transfer inside the AN-22 but did not have any luck.
One of the parts have (50% to 400%) and another part has (200% to 400%) current transfer gains.
What is the expected Current Transfer Rate for the Fig.1 design or did you updated the
BOM to reflect a different part number?
Thank you,
Harry
Hi,
The CTR of the opto-coupler will related to the gain of the control loop. I will suggest you to use the part with less variable gain. The 200% to 400% part should be preferred. Depending on the control loop performance, you could fix the opto-coupler, and adjust the resistor value on the LED side, this will also adjust the control loop gain too.
Thanks
Hi,
Here is my comments to your questions:
1. Yes, you can use the top switch to design the multi-output power supply.
2. Please find the related application note in the following link:
http://www.powerint.com/sites/default/files/product-docs/an22.pdf
3. Yes, you and use the Top switch for the 45W design. You can refer to the power table in the data sheet to select the right device. A software called PI-expert can be helpful for selecting the part too.
4. We usually do the transformer by ourself. But you can select any of the transformer supplier by providing the transformer spec, they should be able to provide to you.