LM5177: Ripple issue

Chen Alex1

Genius 3755 points

Part Number: LM5177

HI SIR

I use the LM5177DCPR to be a adjust power

spec as below:

Vin=24V

Vout=1~48V

Io,max=5A

Po,max=100W

Ripple&Noise expect spec.=1%*Vo+10mV

test report as below by owner PCB board, ripple is over spec, did you have any issue to reduce the noise?

or May I know the evb test result by TI?

Vout 1~5v, output current 1~3A

Thanks

over 1 year ago

0 Stefan Schauer over 1 year ago

TI__Guru 58641 points

Hi Alex,

thank you for using the E2E forum.

The control the output voltage, what control do you use (ATRK or DTRK)?

What this the accuracy of your input signal on ATRK or DTRK?

Note: in this mode this signal is used as the reference voltage.

Best regards,

Stefan

0 Chen Alex1 over 1 year ago in reply to Stefan Schauer

Genius 3755 points

HI stefan

updated for you, below is my circuit

may i know the ripple in the TI evb in same rule?

thanks

0 Stefan Schauer over 1 year ago in reply to Chen Alex1

TI__Guru 58641 points

Hi Alex,

thanks for sharing the part of the schematic but i still do not get:

The control the output voltage, what control do you use (ATRK or DTRK)?
What this the accuracy of your input signal on ATRK or DTRK?

out of that. Can you provide this info

Sorry, I have not measurements for that condition available right now.

Best regards,

Stefan

0 Chen Alex1 over 1 year ago in reply to Stefan Schauer

Genius 3755 points

hi Stefan

I Don't know what is ATRK or DTRK

DId you mean pin 10 & Pin 16?

could you share the mail to me, i can send the schematic for you

thanks

0 Stefan Schauer over 1 year ago in reply to Chen Alex1

TI__Guru 58641 points

Hi Alex,

yes, this are pin 10 & 16.

Just let me know how you adjust the output voltage and the accuracy of that control signal.

Please also let me know the frequency of the output voltage ripple you are measuring.

Best regards,

Stefan

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LM5177: Ripple issue