OPA1654: OPA1654 circuit confirm

Kevin Huang8

Part Number: OPA1654

Hi Team,

Please help confirm OPA1654 circuit,When OPA1654 has not been Powered-ON, I tested it.

The undesirable phenomenon measured is: The DC resistance value of the IC's PIN4 to PIN11 is abnormal when measured with a multimeter. The normal value is about 220K. Test the IC's PIN4 to PIN11 DC resistance on the PCBA. If the value is abnormal, I will remove it and measure it separately. Now the IC removed from the PCBA is tested separately for the DC resistance values of PIN4 to PIN11:

1. 61Ω

2. 2Ω

3. 3Ω

4. 3Ω

5. 2Ω

6. 267Ω

7. 205Ω

8. 281Ω

OPA1654AIDR Schematic.pdf

over 3 years ago

0 Chris Featherstone over 3 years ago

TI__Mastermind 20490 points

Hello,

Are you trying to measure the dc impedance from the power supply VCC to VEE of the OPA1654? Is my understanding correct? Pins 11, and 4 are the supply pins and they are connected to a complex network of transistors forming the amplifier internally. Could you provide more details regarding the issue|?

0 Chris Featherstone over 3 years ago

TI__Mastermind 20490 points

Hello,

Have the devices been working in the application and then stopped? I have started to put together a simulation of your circuit.

Could you verify the markings on the top of the chip package? The numbers and text that are on the package. An image of the top of the chips would be helpful.

0 Kevin Huang8 over 3 years ago in reply to Chris Featherstone

Genius 3245 points

Hi Chris,

Yes, devices been working in the application and then stopped.

0 Chris Featherstone over 3 years ago in reply to Kevin Huang8

TI__Mastermind 20490 points

Kevin,

Can you provide more details for what you observed or suspicions in the circuit you may have? Was there an observed event that caused the devices to stop working such as power supply spikes or anything? The image of the chip is very blurry. Can you type in the numbers on the package as well?

0 Chris Featherstone over 3 years ago in reply to Kevin Huang8

TI__Mastermind 20490 points

Kevin,

I checked your circuit in simulation and it does work as I would expect. Are you observing any spikes on the power supply lines? Generally we would recommend TVS diodes on the supply lines in order to protect from EOS events that could over voltage or over current the devices.

We have a series on EOS. If you look to the right of this link you will see 4 videos 12.1 through 12.4 that will walk you through these events and choosing components for protection.

https://training.ti.com/node/1138807

I have attached the simulation below as well.

Jazz Hipster Circuit.TSC

Audio

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OPA1654: OPA1654 circuit confirm