TPS62871-Q1: Temperature very high when no load

Hi Willy,

Thanks for reaching out to us.

Before we discuss your issue, can you inform me what is the end equipment? Is it for automotive?

Best regards,

Excel

Hi Excel,

Only for CE, Not automotive.

Hello Willy,

Ashika will takeover the thread as she is supporting consumer electronics.

Best regards,

Excel

Hi Willy, 

Could you please provide details of the test conditions such as input voltage, output voltage and the type of analysis to be performed?

Best Regards,

Ashika

Hi Ashika  ,

Input voltage: 5.1V, Output: 0.85V (No Load). When I power on, the device temperature up to 50 °C.

Schematic:

PCB Layout:

Hi Ashika  

Can you see this post?

Hi Willy, 

Yes, I am looking into it. I will get back to you as soon as possible with an explanation.

I understand this is in regard to consumer electronics, but could you please let me know the end equipment?

Best Regards,

Ashika

Hi Ashika  ,

The application scenario is a notebook.

Hi Willy, 

Could you please let me know the test conditions, ie the input and output voltage

I reviewed the schematic, just a couple of inquiries.

- SYNC_OUT is left floating indicating a single device operation, but the PG pin is connected to the input power supply via a resistor? (if it is single device operation, then we must leave the PG pin floating or connect it to GND).

- Could you please let me know why we have a 1uF capacitor connected between VOSNS and GOSNS?

Also, I am reviewing the layout

-Could you please highlight the thermal pad layout?

Best Regards,

Ashika

Hi Ashika  ,

Thanks!

- Test Condition:

Input voltage: 5.1V, Output: 0.85V (No Load). 

- PG Connection:

This pin can be left open or be tied to GND when not used, But pull up to VIN can drive it to high, only for test this device is work normally.

- Remote Sense:

Reduce noise, remote route trace too long (from power module to base board).

- Thermal Layout:

Hi Willy,

Thank you for the swift response.

Could you please let me know how did you measure the temperature of the PCB?

Also, please check if the IC is soldered properly onto the PCB. Improper soldering can result in temperature increase.

Best Regards,

Ashika

Hi Ashika  ,

Use infrared camera. I am sure soldered OK.  Only TPS62871-Q1 has very high temperature, others not.

Hi Ashika  ,

Change compensation value to recommend design (from power designer), Solved !