LM51231-Q1: Request for Suggestion on Automotive Qualified Boost Controller for 12V to 36V @ 12A Application

Hi Mounika, 

Thank you for the response and for sharing the comparison between LM51231-Q1 and LM25122-Q1.

We are specifically targeting a design with a 36V output at 12A, powered from a 12V vehicle battery. While we understand that both parts are boost controllers and that the output current is largely determined by the selection of external MOSFETs and inductors, we’d like to confirm whether either of these controllers can support the required duty cycle for this application. Could you also help clarify any limitations on the maximum duty cycle or current handling constraints of these controllers in such a setup?

Thanks and Regards 

Vinod J 

Mistral Solutions 

Hi Vinod, 

Regarding the Duty cycle limitation from 12V to 36V, I belive there is no issue. I have also attached the DC limit for both devices below. Like you mentioned for the current handling in controllers it is the MOSFET and inductor selection. Additionally LM25122-Q1 has multiphase capability. However, if you want to use the single controller then LM51231-Q1 can be used as well.

LM51231-Q1

LM25122-Q1

Please let me know if you have other questions.

Best regards,

Mounika

Hi Mounika ,

Thank you for your insights and for sharing the duty cycle limits of both devices.

Since our requirement is for approximately 500 W output, we believe the LM51231-Q1 is a suitable choice and would like to proceed with it. We are looking to procure a solution capable of handling around 500 W, and it would be helpful if you could share a reference design that demonstrates this capability using the LM51231-Q1.

Additionally, we would like to procure a development kit for the LM51231-Q1 that supports 500 W, if available, to aid in our evaluation and prototyping process.

Looking forward to your guidance and support.

Best regards,
Vinod J.

Mistral Solutions

Hi Vinod, 

Could you please help me with the End application? Is it for Audio application?

Best regards,

Mounika

Hi Mounika,

The end application is not for audio; it is intended to run BLDC motors.

Best regards,

Vinod J

Hi Vinod, 

We do not have any reference design for this power level with LM51231-Q1 and for the EVM board - please check this link https://www.ti.com/tool/LM5123EVM-BST 

Best regards,

Mounika

Hi Mounika,

Yeah, I’ve seen this EVM (LM5123EVM-BST), but it’s designed for around 100W. In our case, I’m targeting a 500W design. Just wanted to confirm — am I right in assuming that the LM51231-Q1 can still support that power level with the appropriate external components and thermal design?

Thanks and regards 

Vinod J 

Hi Mounika,

Thank you for the input.

I’ve used the Excel calculator provided by TI and have completed the design based on it. I would like to request your review and comments—both on the component values I’ve chosen and the resulting Bode plot.

Looking forward to your feedback

Best regards,
Vinod

.7506.LM5123_Excel_Quickstart_Calculator_for_Boost_Controller_Design.xlsx

Hi Vinod, I see that there is another e2e thread you opened and asking for the final review. I will let Niklas who is handling the other thread to answer to avoid the confusions. 

Please let me know if you have any other questions. if not and If you think this has resolved your questions, please click on resolve check box. 

Thank you and best regards,

Mounika

Hi Mounika,

Thank you and best regards.
Since we need to move faster and have limited time remaining, I went ahead and let Niklas take this further.
Thank you so much for your support! Best regards 

Vinod