TPS552882: Request for Schematic Review.

Hi Tom,

May I know what is the customer and application here?

What is the part number of the MOSFETs, inductor and output capacitors.

BRs,

Bryce

Hi Bryce,

Thank you for your reply.

The part numbers for the MOSFET and inductor are SM333NHQG and PIC10040-4R7MA, respectively.

The load is a motor that draws nearly 10A at startup and stabilizes to an average current of approximately 1A.

Could you please help confirm whether the selected components are appropriate?

Best regards,
Tom

Hi Tom,

1.How long will 10A load last? With R876, output current limit is set to 5A. Recommend to short R876.

2.Recommend to add 100uF E-CAP in Vin and Vout.

3.I cannot find  SM333NHQG. Can you provide datasheet.

4. Isat of inductor is only 8.5A. Recommend to change to a 16A Isat inductor.

5.Recommend to use 50V rated boot cap.

6.Recommend to add RC snubber in SW1 and SW2(2.2ohm+2.2nF first).

7.Recommend to add 0.1uF cap in Vin and Vout.

8.Make sure VCC has 2uF effective capacitance with 5V DC bias.

9.Recommend to connect VCC cap to DGND.

10.Follow layout guideline.

Regards,

Mulin

Hi Mulin,

Thank you for your reply.

The 10A load duration is approximately 500 µs.

Since the 10A load only lasts for 500 µs, is it still necessary to add 100 µF to the input and output capacitors, and to select an inductor with a saturation current rating of 16A in this case?

The MOSFET datasheet is attached.

SM3323NHQG_datasheet_package.pdf

Best regards,
Tom

Hi Tom,

500us is steady state to IC considering switching period, so it is necessary. MOSFET seems ok to me.

Regards,

Mulin

Hi Mulin,

Due to PCB size constraints, I’m unable to place E-CAP at the input and output. Instead, I plan to add 47 µF MLCC at both the input and output, and replace the inductor with one that has an Isat of 14 A.
Would this be acceptable, or do you have any other suggestions? Your advice would be greatly appreciated.

Best regards,
Tom

Hi Tom,

Adding a 47uF MLCC will help. Notice the effective capacitance of the MLCC, make sure it has large effective capacitance. Bench verification is needed.

Regards,

Mulin

Dear Mulin,

I have completed the PCB layout placement. Could I privately share the file with you to help check if there are any obvious major issues?

Best regards,
Tom

Hi Tom,

Please send me a friendship request.

Regards,

Mulin

Hi Mulin,

I also need PCB layout for TPS552882 this chip. Can you send me the files please. I sent you a friendship request.

Hi Mulin,

I have already sent you a friend request. Please check and confirm.

Best regards,
Tom

Hello Tom,

There is a public holiday in China today. Please expect an answer by tomorrow.

Best regards,
Brigitte

Hi Tao,

I accept the request.