• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 1039 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

UCC28C42: How to design Flyback Transformer for SMPS ?

Zaim
Prodigy 90 points
Part Number: UCC28C42

Hi E2E,

I made a design using the webench design tool for a flyback switching power supply that receives 40-300(AC) as input and gives 5 different outputs

with these parameters below

 

1) 24 V - 0.5 A

2) 10 V - 0.7 A

3) -10 V - 0.7 A

4) 5 V - 0.7 A

5) 3.3 V - 1 A

6)15 V (auxiliary)

Switching frequency = 100 Khz

. I am pretty happy with the design and even made a few changes to better fit my application, but I don't know how to interpret the transformer values it gives me because webbench give me the value for only one output. I haven't really studied these types of transformers and I'm not sure how to communicate this information to a supplier to get prototype part for testing. Any advice, or too can design this transformer? 

here is my circuit from tina ti 

I'm looking forward for your answer

  • 0
    TI__Mastermind 26605 points

    Abdelrahman,

    Unless you have actually built the transformer and tested it and you have very specific build instructions (core/bobbin/wire/winding info), I would let a transformer vendor handle the construction details. At a minimum, you need to provide:

    1. VIN_min, VIN_nom, VIN_max
    2. Number of coupled windings with voltage and GND reference for each
    3. Power for each output and total transformer power
    4. Operating frequency
    5. Isolation requirements (functional, basic, reinforced, etc) 
    6. Max allowable duty cycle
    7. control method (CCM, DCM, CMC, VMC). Yours looks like CMC/CCM
    8. Desired primary inductance, leakage inductance
    9. Mechanical dimension constraints
    10. Max hot spot temp

    Let the vendor determine the turns, wire gauges, core/bobbin and wire stack needed to meet your electrical/mechanical requirements. Otherwise, if you want to try and build it your self, there are many good app notes and design guides you can search. Here is the link to the paper and presentation for flyback design from the 2010 TI Power Seminar.

    Regards,

    Steve M