UCC256403: Current Control

Jareth Tan

Part Number: UCC256403

Tool/software:

Hi TI experts,

I am intending to use UCC256403 for an LLC converter application which serves as a constant current source.

Is it possible to configure such that the feedback pin is used to regulate the output current instead of the output voltage? Since having a regulated output voltage is not my objective.

Thanks

6 months ago

0 Manikanta Pallantla 6 months ago

TI__Genius 16155 points

Hi,

You can refer following schematic for constant current control of LLC.

PMP22083 Schematic

Regards

Manikanta P

0 Jareth Tan 6 months ago in reply to Manikanta Pallantla

Prodigy 90 points

Does this controller utilize PFM or PWM control?

0 Manikanta Pallantla 6 months ago in reply to Jareth Tan

TI__Genius 16155 points

The controller uses charge mode control that changes the frequency of the LLC to control output voltage/current.

Regards

Manikanta P

0 Jareth Tan 6 months ago in reply to Manikanta Pallantla

Prodigy 90 points

Several followup questions:

1. Is this chip (half bridge LLC) suitable for power range in 2.4 - 4kW?
2. Is there a way to reliably tune the control loop for the CC and CV control such that there is no overshoot and minimal ripples?
3. During operation, the current reference will be changing between anything that is within 0 - full load. Is this topology still suitable?

0 Manikanta Pallantla 6 months ago in reply to Jareth Tan

TI__Genius 16155 points

1. Half Bridge LLC usually is recommended upto 1kW and below.

2. You can use type 2 compensator for CC-CV feedback.

3. LLC is suitable for any load transient and line transients.

Regards

Manikanta P

0 Jareth Tan 6 months ago in reply to Manikanta Pallantla

Prodigy 90 points

I see. Can this chip be used for Full Bridge LLC. If not, are there any recommended chips for full bridge LLC?

0 Manikanta Pallantla 6 months ago in reply to Jareth Tan

TI__Genius 16155 points

Hi Jareth,

You can use UCC2566xx for full bridge LLC: UCC25660 data sheet, product information and support | TI.com

Since this controller doesn't need VCR caps. For sensing current, you could use a current transformer.

Regards

Manikanta P

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UCC256403: Current Control