LM833:電源間の抵抗値低下

Shougo Nakagawa

Part Number: LM833

I am inputting ±15V to the power supply, but it broke down due to a phenomenon in which the resistance value between the power supplies became low.
There was no problem with the peripheral circuits, only the IC was broken.
I tried introducing noise (period: 16ms, pulse width: 1us, amplitude: 100V to 4.1kV, -100V to -4.1kV) into the power supply line, but nothing failed in the same way.
What could be the cause of the failure?
(Sorry if this is the wrong forum to ask this question)

over 1 year ago

0 Ron Michallick over 1 year ago

TI__Guru**** 167546 points

Hello Shougo Nakagawa,

Are any inputs directly connected to ground? If yes, make sure +15V is never negative and -15V is never positive voltage, during power up or down.

How many samples show the low resistance and how many operate as expected?

0 Shougo Nakagawa over 1 year ago in reply to Ron Michallick

Prodigy 10 points

Confirmation is delayed.
I checked the waveform after the power was turned on, but the positive and negative were not reversed, but were rising in contrast.
I don't have a sample with low resistance, but there are two samples with low resistance at Vcc- and OUT2.
I have one sample that works fine.

0 Ron Michallick over 1 year ago in reply to Shougo Nakagawa

TI__Guru**** 167546 points

Does OUT2 signal go to a connector? Connectors can introduce ESD and EOS.

3 samples; Is this application a new design?

0 Shougo Nakagawa over 1 year ago in reply to Ron Michallick

Prodigy 10 points

OUT2 is connected to the connector through a 100Ω resistor.
±15V is also connected to the connector.
The design is from 2016 onwards.

+1 Ron Michallick over 1 year ago in reply to Shougo Nakagawa

TI__Guru**** 167546 points

Shougo,

If the damaged samples were field returns, the I would suspect the 100 ohms wasn't sufficient to prevent whatever happened in the field that creates an electrostatic discharge or electrical overstress.

A few possibilities are a person touching the connector, unplugging or plugging the connector, and bad/intermittent connections. These would be worse if power was on, but still potentially damaging if power was off.

If failed at factory, check test setups and procedures.

Audio

Audio forum

LM833:電源間の抵抗値低下