UCC256402: Switch from UCC256301, schematic changes

Ambroise Suter

Part Number: UCC256402
Other Parts Discussed in Thread: UCC256301, UCC25640

Hello,

My customer Nestle needs to switch from the UCC256301 to the UCC256402 due to delivery issues.

They tested the '6402 in their exisitng design and observed higher temperature on the transformer due to higher frequencies(?).

Can you pinpoint us the needed schematic changes?

Test Conditions: Input Voltage 230V AC, Output 24V DC@ 4 Amp Continuous Load

UCC25630 – 1

UCC25640 – 2

Temperature of the transformer

Waveform Across Primary Winding – 64 k Hz

Waveform Across Primary Winding – 85 k Hz

Thank you,

Ambroise

over 1 year ago

0 Manikanta Pallantla over 1 year ago

TI__Genius 13245 points

Hi Ambroise,

For the same load and same output voltage, irrespective of controller, frequency of operation should be same for the same resonant tank parameters for a given input voltage. So here, is the output voltage is getting regulated? could you show share the plots for input voltage and output voltage and load currents in both of these cases.

Regards

Manikanta P

0 Ambroise Suter over 1 year ago in reply to Manikanta Pallantla

TI__Expert 3860 points

Hello Manikanta,

Thank you for your fast reply. I have attahced several waveforms on in/out. Do you see anything suspicious?Vertuo UCC256402 Migration Issue.zip

Best regards,

Ambroise

0 Manikanta Pallantla over 1 year ago in reply to Ambroise Suter

TI__Genius 13245 points

Hi Ambroise,

Could you let me know the waveforms that were captured from which version of controller. I couldn't differentiate them. You can also send me a webex meting details anytime today or tomorrow. We can go through them.

Regards

Manikanta p

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UCC256402: Switch from UCC256301, schematic changes