WEBENCH® Tools/TPS25944A: Datasheet and Webench mismatch in calculating RIMON

Amir Azadi

Expert 1105 points

Part Number: TPS25944A

Tool/software: WEBENCH® Design Tools

Hi,

I was checking WEBENCH output with datasheet equations about RIMON.

Page 25: Maximum RIMON is determined by Equation 6.

My design inputs are:

VIN=3.3V

ILIM=1A

with GAIN=52uA/A the R(IMONmax)=13.221K Ohms

But when I use these inputs on WEBENCH, I got: RIMON= 95.3K Ohms which is way higher than the maximum value mentioned in the datasheet by Equation 6.

I have noticed a field on webench desig Advanced Option n inputs: IMON Max Voltage, which is set to 5V by default:

Is this something outside datasheet?

I am getting confused about setting the RIMON on this device.

over 6 years ago

0 Rakesh over 6 years ago

TI__Guru** 105361 points

Hi Aidin,

Thanks for reaching out. Can you please share your application use case details.
Looks like the WEBENCH model is optimized for 12V application. We will look into that. Please use Equation 6 for your 3.3V application.

Best Regards,
Rakesh

0 Amir Azadi over 6 years ago in reply to Rakesh

Expert 1105 points

Hi Rakesh,

My complete design parameters are:

VIN=3.3V (min=max=3.3V)

ILIM=1A

OVP=3.6V

ULVO=2.7V

Cload=680uF

0 Rakesh over 6 years ago in reply to Amir Azadi

TI__Guru** 105361 points

Hi Aidin,

Thanks for the specs.
Please use Equation 6 for your 3.3V application -> R(IMONmax)=13.221K Ohms

Best Regards,
Rakesh

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WEBENCH® Tools/TPS25944A: Datasheet and Webench mismatch in calculating RIMON