TLV62569: TLV62569 input short & damage

Pao Wu

Intellectual 920 points

Part Number: TLV62569

Hi All,

My condition : Vin = 5V , Vout = 1.2V, Iout = 300mA

I have test, It will short input, When load = 300mA

This is my circuit.

When input short, It have reverse current 8A. IC will damage. Do you have any solution could reduce or prevent this problem???

What is high side MOSFET max current??

over 8 years ago

0 Vental Mao over 8 years ago

TI__Expert 5745 points

The high side MOS max current is 3A, it seems that the inrush current breakdown the IC. Which one is you input source, the VCC_5V-SATA or 5V-1V2

0 Pao Wu over 8 years ago in reply to Vental Mao

Intellectual 920 points

Hi Vental,
Thank you for your reply.
Because my customer has test. It will short input pin to GND.
TLV62569 will damage, when input pin short to GND.
Do you have any suggest to solve the problem??

Thanks.

0 Vental Mao over 8 years ago in reply to Pao Wu

TI__Expert 5745 points

What's the value of the resistor R17 and R 18? Do you power the IC by VCC_5V_SATA or 5V_1V2 ?

0 Pao Wu over 8 years ago in reply to Vental Mao

Intellectual 920 points

Hi Vental,
R17 NC, R18 = 0ohm
Do you power the IC by VCC_5V_SATA or 5V_1V2 ? <= 0 ohm short. It is same voltage.

0 Vental Mao over 8 years ago in reply to Pao Wu

TI__Expert 5745 points

OK.I think the main reason about the high reverse current is the current come from the output cap to the input through the body diode of high side MOS when the Vin short to the GND. So the huge current will damage the high side MOS.

For smooth this issue , maybe adding a diode between the Vin and input pin. Thank you!

0 Pao Wu over 8 years ago in reply to Vental Mao

Intellectual 920 points

Hi Vental Mao,
Thank you, I has try schottky diode in input side.(Between input and pin)
It can't protect IC. TLV62569 will damage when input short.
I have add other soution, It can reduce sipke voltage.
But it can't fix the root cause.

0 Vental Mao over 8 years ago in reply to Pao Wu

TI__Expert 5745 points

How about the current of the input with a diode between the power supply and the input pin when you short the input to GND?

And try to move the feedback resistor behind the output cap. The FB pin is very sensitivity. Maybe it will breaks down.

0 Juergen over 8 years ago in reply to Vental Mao

TI__Expert 5425 points

As I understand, during the test the system is still supplied by VCC_5V_SATA. Is this a short to GND or to any other supply rail in the system?
The oscilloscope plot shows a voltage on CH1. Which signal did you measure and where did you put the probe?

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TLV62569: TLV62569 input short & damage