TPS40170: The TPS40170 is hapened to damaged when hot plugged into the 48V supply equipment

user5992127

Part Number: TPS40170

We have a DC-DC buck power supply system (LED display driver board) with 48V input and 24V, 12V, 5V outputs.

The 48V input comes from a 1U SPS rectifier and is connected to the led driver board through a 5 meter long cable.

The 48V power equipment supplys 48V all the time, and it happened that the TPS40170 is damaged when the board is powered on by plugged the power cable into the connector's of the borad.

The 24V output is lost, and resumes to work by replacing a new TPS40170 chips.

Pls helps to find out the cause and how to resolve it ,thanks.

over 5 years ago

0 user5992127 over 5 years ago

Prodigy 60 points

Add the sch below.

dc-dc_v12_1218.pdf

0 Iven Su over 5 years ago in reply to user5992127

TI__Expert 8245 points

Hi,

It looks the input capacitors are not large enough, 30uF should be fine as Webench recommends. Actually you can use Webench to update your design, thanks.

0 user5992127 over 5 years ago in reply to Iven Su

Prodigy 60 points

Iven Su said:

Hi,

It looks the input capacitors are not large enough, 30uF should be fine as Webench recommends. Actually you can use Webench to update your design, thanks.

There are two 330uF Aluminum electrolytic capacitors and 8 2.2uF ceremic capacitors.

I simulated the circuits using Webench, but the component's parameter seems not better, and then use a design copeid from other application.

0 Iven Su over 5 years ago in reply to user5992127

TI__Expert 8245 points

Hi,

Actually if you keep the input source close and input capacitors very close to Vin/GND pins of the device, the device will not be easily damaged. Please check the Vin spike (just probe on a very close input capacitor) when power-on.

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TPS40170: The TPS40170 is hapened to damaged when hot plugged into the 48V supply equipment