LM5176: Schematic and PCB Review

Vinay Mande

Prodigy 85 points

Part Number: LM5176

Tool/software:

We are developing a Buck-Boost Converter using LM5176 and using reference from SNVC208

Following are specs of the design:-

Vin:- 6 to 51V

Vout:- 12.2V

Iout:-15A

Switching Frequency:- 440 kHz

We need help with reviewing the schematic as well as the PCB board for the same. Will share the files on private chat.Please do send me a friend request so that we can continue chat.

Please do look into the schematic and PCB and let me know if there are any changes to do.

Thanks & Regards

Vinay Mande

6 months ago

+1 Stefan Schauer 6 months ago

TI__Guru 58521 points

Hi Vinay,

if you hoover over my name you can select send private message.

Once done please drop a note here is well so that i know to check my private messages.

Could you please attach the filled out LM5176 Design Calculator to this thread? This would be the most efficient workflow for us to do a schematic review.

Best regards,

Stefan

0 Vinay Mande 6 months ago in reply to Stefan Schauer

Prodigy 85 points

Hi Stefan,

I have resended the files with correction in private chat. Please check schematic and let me know is it fine.

Best regards,

Vinay

+1 Stefan Schauer 6 months ago in reply to Vinay Mande

TI__Guru 58521 points

Hi Vinay,

please see my reply in the private chat.

Best regards,

Stefan

0 Vinay Mande 6 months ago in reply to Stefan Schauer

Prodigy 85 points

Hi Stefan,

I have send required files in private chat.

Please do check it.

Best regards,

Vinay

0 Stefan Schauer 6 months ago in reply to Vinay Mande

TI__Guru 58521 points

Hi Vinay,

some comments on the quickstart calculator review:

- suggested Rsense is 2.9mOhm but you have selected 6.8m -> controller might trigger overcurrent in normal operation

- C_Slope selected higher then recommended. Should be selected or next lower level

- desired cross over frequency set to 44kHz but f_RHPZ is 8kHZ for 6V Vin -> max f_c < 2.5kHz -> compensation not stable (5.5k / 22n / 680p would be better)

Schematic:

I would start with ~ 2.2Ohm gate resistors and not immediately go to the max.

Best regards,

Stefan

Power management

Power management forum

LM5176: Schematic and PCB Review