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WEBENCH® Tools/UCC28C40: UCC28C40

Part Number: UCC28C40

Tool/software: WEBENCH® Design Tools

Hi, Regarding my inquiry about the flyback PWM controller with required specifications, I decided to set up the flyback circuit board with the UCC28C40 PWM Controller for the test and made a customize design using Webbench. Also, I have ordered all related materials, but did not make the board yet.

Vin= 12-36V
Iout =100-120mA
Vout= 24V or +/- 12V

The problem is, the Transformer part should be hand wind and the air gap seems not prevent core saturation because the air gap within the magnetic core structure seems bigger than it should be (maybe). Because I have winded the transformer and measure a much smaller inductance on the input, AUX and output side.

Is there any alternative for the transformator? or how can I optimize it?

Maybe I do not measure the transformer properly.

So, what is your method to measure?



Transformer Infos from Webbench as  belew

UCC28C40DR 12V-32V to 24.00V @ 0.12A

1. Core Part Number B65807P0000R049

2. Core Manufacturer TDK

3. Coil Former Part Number B65808E1508T001

4. Coil Former Manufacturer TDK


Turns 12.0      AWG 26.0    Layers 2.0      Strands 2.0              Insulation Type Heavy              Insulated              Magnet Wire


Turns 9.0        AWG 28.0     Layers 1.0      Strands 1.0             Insulation Type Heavy             Insulated              Magnet Wire


Turns 19.0       AWG 29.0    Layers 2.0      Strands 1.0              Insulation Type Triple              Insulated           



Transformer Parameters

# Name Value

1. Lpri 1.06E-4H

2. Inductance Factor(Al) 736.0nH

3. Npri 12.0

4. Nsec 19.0

5. Naux 9.0

6. Core Type RM6 LP

7. Core Material N49

8. Bmax 0.19T

9. Switching Frequency 98.85kHz

10. DMax 0.6

11. Ipk(Primary) 0.82A

12. Irms(Primary) 0.4A

13. Ipk(Secondary) 0.52A

14. Irms(Secondary) 0.21A

Design Assistance

1. UCC28C40 Product Folder : : contains the data sheet and other resources.


Thank you for your support