LM5143-Q1: Is MOSFET fine for our working

Hello Shubha 

Please download the quick start at https://www.ti.com/lit/zip/SNVC229 , input your electrical specifications and componenet selections, and share the completed quck start with us. 

Also, please send us a higher resolution schematic. I cannot read the componenet values. 

- EL 

Hi Eric,

Thanks for your reply, will add the specification and will share you the same.

The attached schematics is image, I think we could zoom and see the clear design. Still if not clear, kindly let me know 

Hello Shubha 

I can read the values now. Please share the quick start when it is ready. 

-EL

LM(2)5143-Q1 quickstart design tool - revB2.xlsm - B1.xlsx

Hi Eric,

Kindly find the quick start attached here. 

Note: Compensation networks are not tuned, DCR based current sensing is used

Hello Shubha 

I will reply when it is ready. 

-EL

Hello Shubha 

Please send me ZIPped file. Your excel file is broken....\

-EL

Hi Eric,

Kindly find the zip file attached here.

LM(2)5143-Q1 quickstart design tool - revB2.xlsm - B1.zip

Hello Shubha 

I don't think it is my laptop issue. I guess you modified the original excel file but I am not sure. 

-EL 

Hi Eric,

Could you now check in the attached file 

LM(2)5143-Q1 quickstart design tool - revB2_01062023.zip

Hello Shubha 

It works now. Please refer my comments below.

• VOUT1 is 5V while it is 3.3V in your quick start. 
• Please select Inductor DCR sensing at G16 cell, OR add sense resistors. 
•  DITH should be tied to VDDA to disable the spead spectrum. 
• R0008, C0009, C0010, R0024, C0028, C0029 values do not match with the compensation componenets in the quick start. 
• PG2 pin is floating now. 

-EL 

This information is for reference purpose only and TI does not guarantee the accuracy. Buyer/User is solely responsible for the design, validation, and testing of its applications as well as for compliance with all legal, regulatory, standards , and safety-related requirements concerning its applications. 

Hi Eric,

Below attached the updated sheet .

• VOUT1 is corrected in sheet.
• Inductor DCR Sensing has been enabled in sheet 
• DITH config is changed in the sheet 
• The compensation circuit has to be tuned as mentioned like earlier
• PG2 pin has been pulled up  

  Could you please review on the MOSFET and inductor whether these parts suits our design. Since we could not conclude over that.LM(2)5143-Q1 quickstart design tool - revB2_02062023.zip 

Hello Shubha 

Thanks for the update. It looks like MOSFETs are okay. 

I found the inductor direction on CH1 is different than CH2. Usually 'DOT' direction faces the switching node. 

The minimum peak current limit using 6.6mOhm resistor is 10A, which is too close to the maximum output current 9A. The minimum peak current limit should be greater than ~ 12-12.5A considering inductance variations. 

Please review these equations. I think 2.87k + 14.3k ohm + 220nF combination of DCR sensing network can be a good starting point. 

-EL

Hi Eric,

The part numbers in the schematic image are the one we are going to use 

Inductor : ETQP6M3R3YLC

MOSFET: BSZ100N06LS3GATMA13YLC

With some changes in the DCR value have updated the sheet and attached below.

Also could you clarify on the first equation how you arrived at the current sense resistor.

LM(2)5143-Q1 quickstart design tool - revB2_05062023.zip