WEBENCH® Tools/LMZ31710: Error on creating a design through Webench

Cedrick

Part Number: LMZ31710
Other Parts Discussed in Thread: TINA-TI

Tool/software: WEBENCH® Design Tools

Hi,

I hope you are doing well.

Our customer was trying to simulate the LMZ31710 with 5V+/-5% input voltage, 0.8V/9A output current/voltage. According datasheet (pages 9, 13, 14, 15, 22) should not be any issue to use LMZ31710 with those parameters. But trying to simulate with Webench results with error message "Calculated duty cycle exceeds limit". Even with lower output current, other input voltages - the duty cycle message exist. The minimal output voltage that can be simulated is 0.9V.

Is there issue with the Webench, or indeed the regulator cannot get down to 0.8V ?

Looking forward to your response.

Regards,

Cedrick

over 4 years ago

0 Kris F over 4 years ago

TI__Genius 17905 points

Hi Cedrick,

I'm checking with the WEBENCH team on this and will get back to you by tomorrow.

Regards,
Kris

0 Kris F over 4 years ago in reply to Kris F

TI__Genius 17905 points

Hi Cedrick,

The team identified an issue with the WEBENCH model that was causing <0.9Vout to fail, and is working to fix it. I will let you know when I have a date for when the update will be released to ti.com.

Kris

0 Cedrick over 4 years ago in reply to Kris F

TI__Expert 8270 points

Hello Kris,

Thank you for this information.

For the meantime, as the Webench team is working on it, can you please help me provide a TINA-TI circuit (.TSC) for the customer's requirement so they can simulate this part?

I really appreciate your help. Thank you!

Regards,

Cedrick

0 Kris F over 4 years ago in reply to Cedrick

TI__Genius 17905 points

Hi Cedrick,

My suggestion would be to advise the customer to create a close design in WEBENCH such as 5Vin 0.9Vout 9Aout, and then export the design to TINA-TI. Then, in TINA-TI, modify the Rset resistor from 2.87kohm to 4.32kohm to change the output to 0.8V.

Can you check if they can follow this process? If you or they run into issues, let me know.

Kris

0 Kris F over 3 years ago in reply to Kris F

TI__Genius 17905 points

Hi Cedrick, I just wanted to give an update that the WEBENCH model will be updated on ti.com in a couple of weeks to allow output voltages <0.9V.

0 Kris F over 3 years ago in reply to Kris F

TI__Genius 17905 points

Cedrick, the update was released. You can inform the customer that they can create their design in WEBENCH for 0.8Vout 9A now.

0 Cedrick over 3 years ago in reply to Kris F

TI__Expert 8270 points

Hi Kris,

Thank you for the update!

Have a great day,

Regards,

Cedrick

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WEBENCH® Tools/LMZ31710: Error on creating a design through Webench