WEBENCH® Tools/LMR14010A: LMR14010A buck converter with 3.3 V output

Dejan Hrovatin

Part Number: LMR14010A
Other Parts Discussed in Thread: LMR14030, LMR14020, LMR14006, LMR16006

Tool/software: WEBENCH® Design Tools

Hi,

I would like to use a LMR14010A buck switcher as converter from 10 V - 17 V to 3.3V, with max. current output of 0.3 A. If I put this values in WEBENCH^® Designer I get an error: Design is unstable. Why I get this error exactly?

Many thanks,
Dejan.

over 6 years ago

0 Frank De Stasi over 6 years ago

TI__Guru 64365 points

I will move this to the Webench forum

0 Atul_Kulkarni over 6 years ago

Genius 4910 points

Hi Dejan,

For the current condition Vin~10-17 V to Vout ~ 3.3V Iout ~0.3A , the device is violating the phase margin due to which Webench is unable to create design. Please note that the designs can be created for the device for output current greater than 0.39A.

Thanks and Regards,
Atul

0 Dejan Hrovatin over 6 years ago in reply to Atul_Kulkarni

Intellectual 360 points

Hi Atul,

exactly, current consumption of my load will change between 20 mA and 300 mA. Just for clearity, is OK if I use this variant of buck converter for my application?

Many thanks,
Dejan.

0 Atul_Kulkarni over 6 years ago in reply to Dejan Hrovatin

Genius 4910 points

Hi Dejan,

Could you please let us know the variant that you are referring to?

Thanks and Regards,
Atul

0 Dejan Hrovatin over 6 years ago in reply to Atul_Kulkarni

Intellectual 360 points

Hi Atul,

with this variant I meant if this model of buck converter will be ok for my application with current consumption between 20mA and 300mA. I know that phase margin is connected to stability of device, but I don't know what exactly this means in my example.

Sorry for unclearity.
BR,
Dejan.

0 Atul_Kulkarni over 6 years ago in reply to Dejan Hrovatin

Genius 4910 points

Hi Dejan,

For the current input condition LMR14010A is unstable.
We would suggest to use LMR14020 or LMR14030 for your application.

Thanks and Regards,
Atul

0 Dejan Hrovatin over 6 years ago in reply to Atul_Kulkarni

Intellectual 360 points

Hi Atul,

I'm searching for maybe something in SOT-23 package. What do you think about LMR14006?

Many thanks,
Dejan.

0 Dejan Hrovatin over 6 years ago in reply to Dejan Hrovatin

Intellectual 360 points

Hi,

I think that another option could be LMR16006. In datasheet, the graph efficiency vs. current (@Vout = 3V3) is shown. I can see that graph starts at 1mA, but If I put in Webbench next values: Vin=12V, Iout=50mA and Vout=3V3, I still get an "error": design is unstable. How can I understand this "error" in this example?

Many thanks,
Dejan.

0 Atul_Kulkarni over 6 years ago in reply to Dejan Hrovatin

Genius 4910 points

Hi Dejan,

Please refer LMR14203X which is SOT-23 package and meets other requirements.

Thanks and Regards,
Atul

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WEBENCH® Tools/LMR14010A: LMR14010A buck converter with 3.3 V output