LM5023: Flyback isolated AC/DC converter, tina ti

ABHISHEK KUMAR

Part Number: LM5023
Other Parts Discussed in Thread: TPS92314, UCC28056, UCC28051, UCC28050

Hii Everyone

I am using the LM5023 PWM controller for the design of a 19 V, 60 W AC-DC converter. For this design, how can we improve its power factor?

Thanks and Regards

Abhishek

over 2 years ago

0 Mike O' over 2 years ago

TI__Guru 66135 points

Hello,

The LM5023 is a QR flyback controller that does not have power factor correction. At best I believe you can achieve a PF of 0.45 with this device. To achieve more than that you will reguire power factor correction.

The TPS92314 is a primary side regulated PSR PFC flyback controller that you can use for an offline flyback with power factor correction. You could possible use this for your design instead to achieve a PF of 0.9.

These following links will bring you to the data sheet and user's guide for the TPS92314 evaluation module.

https://www.ti.com/lit/ds/symlink/tps92314.pdf

https://www.ti.com/lit/ug/sluua17a/sluua17a.pdf

If you decide to pursue using the TPS92314 and have questions regarding it's use an operation. Please repost with TPS92314 in the thread title so the appropriate engineer can help you with this?

Regards,

Mike

0 ABHISHEK KUMAR over 2 years ago in reply to Mike O'

Prodigy 120 points

Is it right to use an extra PFC circuit in this ac-dc converter to improve pf (like boost PFC after full-wave rectifier)?

0 Mike O' over 2 years ago in reply to ABHISHEK KUMAR

TI__Guru 66135 points

Hello,

You can do this as well. The UCC28051 or UCC28056 would work for that application as well. They are critical conduction boost controlers.

Regards,

0 ABHISHEK KUMAR over 2 years ago in reply to Mike O'

Prodigy 120 points

Can you please suggest reference designs or papers where they are using an extra boost PFC circuit in AC-DC converter of power rating less than 100 w?

0 Mike O' over 2 years ago in reply to ABHISHEK KUMAR

TI__Guru 66135 points

Hello,

The following will bring you to a link that shows how to design the UCC28050/1 devices in PFC boost. The output is 390 V typically and you would feed this into your flyback. In the example in the data sheet the design is for 100 W.

https://www.ti.com/lit/an/sluu138a/sluu138a.pdf

Regards,

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LM5023: Flyback isolated AC/DC converter, tina ti