LM5034: Duty can't synchronize for OUT1/ OUT2

Eric Chen4

Expert 2370 points

Part Number: LM5034

Hi,

Now we use LM5034 active clamp application and spec is below then schematic as attached.

Vin:36-75V

Vout:14.5V/30A

Freq:100KHz

Then findout LM5034 OUT1/ OUT2 duty can't synchronize as below Fig.1

Fig1.

Would you kindly provide your suggestion for our reference first?

Thanks.

450W-mos2.pdf

Regards,

Eric

over 6 years ago

0 Peter Meaney over 6 years ago

TI__Mastermind 31580 points

Hi Eric,

The LM5034 is an interleaved controller so the OUTA and OUT2 will be 180 degrees out of phase. This reduces the switching frequency ripple in both the input and output stages of the power stage.

TI has an EVM that you can order, www.ti.com/.../lm5034eval

Regards

Peter

0 Eric Chen4 over 6 years ago in reply to Peter Meaney

Expert 2370 points

Hi Peter,

Thanks your quickly response.

If duty can't open for no load, What causes this phenomenon? Show Fig. 3 for your reference.

Please kindly provide your suggestion for reference.

Thanks.

Regards,

Eric

0 Peter Meaney over 5 years ago in reply to Eric Chen4

TI__Mastermind 31580 points

Hi Eric,

This looks like there is a sub harmonic oscillator on one of the COMP pins voltage waveform. Can you post the voltage on the COMP pins?

Thanks

Peter

0 Peter Meaney over 5 years ago in reply to Peter Meaney

TI__Mastermind 31580 points

Hi Eric,

Since there has been no activity on this post I will close it.

please open a new post if you have a new question.

Regards

Peter

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LM5034: Duty can't synchronize for OUT1/ OUT2