TPS65250: TPS65250 doesn't output

takahiko yokota

Part Number: TPS65250

I posted the following E2E thread before.
My customer evaluated TPS65250 with floating 31~35pin not to use GASP mode.
But EN1~3, V3V and V7V were 0V.

e2e.ti.com/.../2401663

I found the following E2E thread.
In this thread, it were written that 31pin connect GND, 32~34pin connect VIn and 35pin is open.
How should I connect the 31~35pin to?

e2e.ti.com/.../110722

Best regards,

Yokota

over 6 years ago

0 Jason Wang (BSR-MV) over 6 years ago

TI__Genius 9550 points

Yokota,
Will confirm with EVM and give feedback.

0 takahiko yokota over 6 years ago in reply to Jason Wang (BSR-MV)

Mastermind 7135 points

Hi Jason-san

Thank you for your polite response.
Could I get your evaluation result?
Please let me ask you further questions.
Are the power supply for gasp circuit supplied by Vin or by internal circuit?

Best regards,
Yokota

0 Zhao Ma over 6 years ago in reply to takahiko yokota

TI__Genius 15135 points

Hi, Yokota

1. I check this test on EVM.

After floating 31~35pin, EN1=EN2=EN3=3.2V, the V3V=3.37V, the V7V=6.2V.

The Buck1, Buck2, Buck3 can normal working.

So floating 31~35pin don't affect the Buck1/2/3.

The gasp circuit is independent from Buck1/2/3.

2. The power supply for gasp circuit is supplied by Vin.

0 takahiko yokota over 6 years ago in reply to Zhao Ma

Mastermind 7135 points

Hi Zhao-san

Thank you for the confirm.

My customer evaluated it floating 31~35 terminal and V3V and V7V were 0V.

But when they connected 33 terminal to VIN, V3V was outputted (but it broke after that).

I checked the other circuit, but I couldn't find any problems.

Please let me ask you just in case.

33 terminal of TPS65250 is written input according in table function.

Should I float 31~25 terminal?

Best regards,

Yokota

0 Zhao Ma over 6 years ago in reply to takahiko yokota

TI__Genius 15135 points

Hi, Yokata

What is meaning of "but it broke after that"? is IC damaged?

I made a mistake, i didn't cut off Vin trace for pin33 in last test.
Todday i cut off Vin trance for pin33 and retest EVM.
The resut is same with you, after power on, the V3V and V7V are 0V, the Buck1/2/3 don't work, and i don't see IC damage.

So the correct setup:
Pin 31, 32, 34, 35 can be floating, but the Pin 33 must be connected to VIN. --> the Buck1/2/3 and V3V & V7V can normal working.

0 takahiko yokota over 6 years ago in reply to Zhao Ma

Mastermind 7135 points

Hello Chao-san

Thank you for the confirm.
"but it broke after that" is damaged TPS65250 after inputting Vin.
My customer evaluated TPS65250 as 31, 32, 34 and 35 terminal is floating and 33 terminal connect to Vin. But V3V and V7V are 0V and Buck1/2/3 don't work.
I'm checking the circuit and layout.

Best regards,
Yokota

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TPS65250: TPS65250 doesn't output