TPS563201: Output voltage not getting generated

Dhara Pandya

Part Number: TPS563201

Hi,

I have used this IC (TPS563210) to generate voltage 1.35v(U4) and 1.8v (U5) for FPGA. Please refer the schematic shared and also the waveforms of DSO.

But when I probe the output it reads around 0.168v (TP19) and 0.146v ( TP20). As soon as I manually short-link the two voltage divider resistor (R17.2 and R18.1) for U4 and (R21.2 and R22.1) for U5, the spike of around 4.5v is observed and then it settles down to stable 1.8v and 1.35v respectively. Also note thata these two resistor ends are already short on PCB via route (width of 0.5mm).

Visual inspection of soldering, dry solder and component touch-up are already iterated. Also this circuit config. was studied and referred using TI web-bench tool.

What can be the reason for not getting output voltage..?

voltage gen_sch.doc

-Dhara

over 8 years ago

0 Anthony Lang over 8 years ago

TI__Expert 4875 points

HI Dhara,

From your schematic, I found that you assign the pin number for pin 4 and 5 wrongly. Pin 4 should be PG and pin 5 should be SS. You flipped them and this could be the reason the IC could not soft start.

Best,
Anthony

0 Dhara Pandya over 8 years ago in reply to Anthony Lang

Expert 1220 points

Hi Anthony,

Thanks for your response.

I have taken the reference of web bench project for designing the power section of FPGA. Check out the attached document. From this attached project sheet TPS563210 (SUPPLY_1 = 1.8V, SUPPLY_6 = 1.8V) and TPS562210 (SUPPLY_8 = 3.3V) is behaving the same as I mentioned in my previous post.

In my schematic, I have implemented the same circuit from web-bench project in my hardware design. Can you please guide with that..

Thanks,

Dhara

webench_project_fpga.pdf

0 Best Power Drill over 8 years ago

Prodigy 10 points

I really dont know much about the electronics information but I want to ask if you providing some inputs then it will definetely produce some output. Or you can try more ways to generate the output.
http://bestpowerdrills.net/

0 Anthony Lang over 8 years ago in reply to Dhara Pandya

TI__Expert 4875 points

Hi Dhara,

I did not find issues of your schematics. One thing I want to bring out is that TPS56x21x is NRND. We have an improved version TPS56x21xA. A version improves on the accuracy of soft start time. Please try to switch to A version. Thanks!

0 Dhara Pandya over 8 years ago in reply to Anthony Lang

Expert 1220 points

Hi Anthony,

Thanks for the prompt reply..
I have used the IC with the 'A' version.. TPS563210ADDFT and TPS562210ADDFT only that in previously shared schematic design full part name is not mentioned.

-Dhara

0 Anthony Lang over 8 years ago in reply to Dhara Pandya

TI__Expert 4875 points

Hi Dhara,

Thanks for your info. Any more question please let me know.

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TPS563201: Output voltage not getting generated