Hi,
I am using TPS61030 IC in buck boost application. The IC was working fine for 3-4days continuously and when the engineer touch the thermal pad of the IC from back side the IC failed.
The currently drawing from the IC is just 700mA.
pls note: while accessing the board Engineer was wearing wrist strap and it was grounded properly.
what could be the issue. out of 8 boards 2 boards got failed.
Regards
Raghu
Thank you for using the forums. I would encourage you to put more information in your subject lines. A better title for this post would be "TPS61030 draws high current after being touched". 'Issue' is a very broad term that encompasses most of the posts on these forums.
If the board that the TPS61030 was on and its ground was not at earth potential, then touching it with something at earth potential still applies an ESD shock due to the voltage difference between the different nodes of this circuit. You will need to see if this is a realistic situation in your end equipment and protect your system accordingly.
Also note that the TPS61030 is not a buck boost converter. The TPS63020 and TPS63060 are buck boost converters that may be better suited to your application.
I am sorry for the for creating confusion. We do require boost only. So TPS61030 holds good for our design.
I checked the design and currently we are using DC Power supply for testing purpose,So our ground and earth potential are same.
Still if i touch the IC it will fail.And once i replace the IC and and touch the IC some time it fails and some time it is working fine. We do have a ESD protection device for the circuit and it will be battery operated device.
Any other things need to take care, i am attaching the schematic also for your reference.
After generating 5V the out put is also connected with 3.3volts Linear regulator and 4.7volts low drop out regulator
Thank you for attaching your schematic. It looks reasonable except for the ferrites between the grounds. We recommend connecting the grounds together directly. Voltage offsets between them can cause issues. You might rerun this test with the grounds tied directly together.
Every power supply in our lab has isolated output terminals. A few of our power supplies have a third terminal for earth ground but this is not normally connected.
In any case, you will need to evaluate if your end customer (who is not grounded with an ESD strap) will be able to touch the IC and provide an ESD shock. If they can, you will need to protect against this. In most end equipments I have seen, the customer cannot touch the PCB at all.