TPS546D24A: CORE_0.85V Debug

Hi Shifali,

Please send us the schematic and the layout, as well as where you are measuring the output voltage.
The TPS546D24A should regulate the output voltage to the point where you connect the remote sense.

Thank you,
Tomoya

Hi Tomoya,

I have shared my schematics and layout file.

Thanks

1460.iW-EMEW7-BF-01-R1_0-REL1_1-TPS546D24ARVFR.brd8780.TPS546D24ARVFR.pdf

Hi Shifali,

Looks like you have a test point (TPH5). Is this where you're measuring 0.9V? And where are you referencing for GND? 

Your regulation point is at the FPGA (circled in RED), so the voltage at the test point will be higher to compensate for the voltage drop due to PCB resistance. 

Thank you,
Tomoya

Hi Tomoya,

I've probed the voltage across C103 and shared the waveform with you, using a scale of 100us/division. Do you think we could resolve this issue by making changes to the schematics?

Thanks,

Shifali

Hi Shifali,

A digital multimeter would be a better option for accurately measuring DC voltage. Please use a multimeter and let us know what you are measuring with or without the load. 

Also, please measure the voltage across C43. This is where the device is regulating, and expect to see 0.85V. 

Thank you,
Tomoya

Hi Tomoya,

 I've checked the voltage across C103, and it's showing 0.852V. As for C43, the voltage measurement is 375mV.

Thanks,

Shifali

Hi Tomoya,

The voltage measured across C44 is 0.85 mV.

Thanks,

Shifali N