LMR16010: LMR16010 start up VOUT drop issue

Red Yen

Part Number: LMR16010

Hi Support team,

my customer encountered start up VOUT negative slew rate issue, the same thing also occurred in EVM while output have loading

following is measured result in EVM

VIN 50V VOUT 5V @ 0.15A operation frequency is 300Khz

BLUE SW

purple VOUT

VIN 50V VOUT 5V @ 0.5A frequency is 300Khz

BLUE SW

purple VOUT

over 3 years ago

0 J Arrigo over 3 years ago

TI__Mastermind 28020 points

Hi Red,

Can you share your schematic? How much output capacitance do you have on the design?

Can you reduce the Vin to 24V and see if the spikes go away?

This device transitions through Fsw during turn-on. Need to check minimum on time or inrush if charging large output capacitance during the transition.

Regards, Jason

0 Red Yen over 3 years ago in reply to J Arrigo

TI__Expert 4310 points

Hi Jason,

the waveform was measured by EVM, it's help if increasing the cap like 470uF, but it's really huge capacitance needed

any other way to overcome it?

0 J Arrigo over 3 years ago in reply to Red Yen

TI__Mastermind 28020 points

Hi Red,

Can you share your schematic? You can send directly to me if you do not want to post on the public forum.

jarrigo@ti.com

Thanks, Jason

0 J Arrigo over 3 years ago in reply to J Arrigo

TI__Mastermind 28020 points

Hi Red,

I haven't heard from you in a while. I hope that means that you have resolved your issue. If not, please respond or send me an email.

I will close this post for now, but if you need to post, please reply.

Regards, Jason

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LMR16010: LMR16010 start up VOUT drop issue