WEBENCH® Tools/LM5176-Q1: Regulator does not generate desired voltage

Bill Adams1

Part Number: LM5176-Q1
Other Parts Discussed in Thread: LM5176

Tool/software: WEBENCH® Design Tools

I have a webench design which is not starting up. The design is for a boost regulator with an LM5176-Q1. The design generates 40V from a 20V input. I have verified that the schematic and layout match the WEBENCH design. The output is 25V instead of the intended 40V.

over 5 years ago

0 Bill Adams1 over 5 years ago

Prodigy 190 points

That should read 2.5V.

0 Garrett Roecker over 5 years ago in reply to Bill Adams1

TI__Mastermind 21720 points

Hi Bill,

Thanks for reaching out with your question and for using the LM5176 in your design.

Can you please post the schematic and the application specifications (VIN range, VOUT, IOUT max)

Thanks,

Garrett

0 Bill Adams1 over 5 years ago in reply to Garrett Roecker

Prodigy 190 points

MotorVoltage.pdf

0 Bill Adams1 over 5 years ago in reply to Bill Adams1

Prodigy 190 points

The input voltage is 23-25V, the output voltage is 40V. Maximum output current is 7.5A.

0 Bill Adams1 over 5 years ago in reply to Bill Adams1

Prodigy 190 points

It looks like WEBENCH is off a little in the EN/UVLO threshold setting. The regulator never switched out of Standby. When I increased the value of R528 from 14.3k to 18k, the regulator started switching and produced 38V.

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WEBENCH® Tools/LM5176-Q1: Regulator does not generate desired voltage