INA220 latch-up

Peter Lameijn

Prodigy 50 points

Other Parts Discussed in Thread: INA220

We use the INA220 in a fairly basic circuit (8 pcs on one board), and we had quite a few latch-ups.

Is this circuit extra sensitive for latch-up and which pins are mostly the cause?

What is the best remedy to avoid it?

over 10 years ago

0 Guang Zhou over 10 years ago

TI__Mastermind 36810 points

Hi Peter,

INA220 passed standard latch up test JESD78, and I’m not aware of similar complaints. Can you be more specific on how you came to the conclusion that it is latch up, and not some other issues, that is causing the problem? What are the visual/electrical indications? Does the device get damaged randomly on the the PCB or is there any pattern? Have the supply/signal/ground levels been looked at for worst case?

Regards,

Guang-Apps CS Products

0 Peter Lameijn over 10 years ago in reply to Guang Zhou

Prodigy 50 points

Hi,

It looks like a latch-up, because the chip gets 'smelly' hot with all voltages normal.
Powering off and on and it works again.
I could protect all pins, but thats quite some extra hardware, so I wondered if some
pins are more prone to latch-up;
Problem is that it's difficult to determine the cause of the problem.

Regards
Peter.

0 Peter Lameijn over 10 years ago in reply to Peter Lameijn

Prodigy 50 points

Is it a problem if the bus voltage comes up before the 3.3v power for the chip is up and running?

0 Jason Bridgmon over 10 years ago in reply to Peter Lameijn

TI__Genius 14825 points

Having the bus voltage rise before the power supply should be just fine.

Are you running a PWM or other kind of fast-rising-edge waveform into the device?

0 Peter Lameijn over 10 years ago in reply to Jason Bridgmon

Prodigy 50 points

No PWM used. The bus voltage input is used to monitor a voltage from a potmeter.

0 Jason Bridgmon over 10 years ago in reply to Peter Lameijn

TI__Genius 14825 points

Have you tried removing R7 or R8 (not simultaneously) to see if either of them is responsible for the odd behavior and the behavior goes away if they aren't present? This is a very strange thing to be happening for such a simple circuit subdiagram. Let us know and we'll keep trying to debug this!

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INA220 latch-up