LT1054: the device is failed

ccKevin

Part Number: LT1054

To whom it may concern,

I use the LT1054IP to convert +12V to -12V. The +12V/-12V are used for the power of the OP amplifier. I measure the current in the -12V circuit, the current is 14mA . Sometimes the LT1054 will fail, the voltage will be 0.X V. I think that the output current of LT1054 is sufficient for my load current(14mA). Can you give me some advice? The attached file is my circuit. Thank you.

over 7 years ago

0 Youhao Xi over 7 years ago

TI__Guru* 76815 points

The schematic looks right. What type of capacitors did you choose?

0 ccKevin over 7 years ago in reply to Youhao Xi

Prodigy 130 points

The photograph is my actual PCB. The capacitors are shown above.

0 Youhao Xi over 7 years ago in reply to ccKevin

TI__Guru* 76815 points

Once the LT10454 fails, is there any external capacitor also failed?

0 ccKevin over 7 years ago in reply to Youhao Xi

Prodigy 130 points

The appearance of the capacitors is OK. I change another LT1054, the voltage is OK (-12). So, I think that only LT1054 is fail.

0 ccKevin over 7 years ago in reply to Youhao Xi

Prodigy 130 points

Can you give me some advice? What are the possible reason that cause LT1054 failed?

0 Youhao Xi over 7 years ago in reply to ccKevin

TI__Guru* 76815 points

We have studied this case and so far we cannot figure out what is really going wrong. Does this one time failure, or you keep having the same problem? How often? And, is your 14mA your load current always constant, of it may change during operation?

0 ccKevin over 7 years ago in reply to Youhao Xi

Prodigy 130 points

The power board is my new design. We have used 100~200 pieces of the power boards, and there are about 10 pieces of the LT1054 failed. I think the load current 14mA is constant. If I add one serial resistor to limit the possible overload current, how about do you think?

0 Youhao Xi over 7 years ago in reply to ccKevin

TI__Guru* 76815 points

Hi ccKevin,

Adding the limit resistor seems to be a good idea. Please add between the output capacitor and your load.

Thanks,
Youhao Xi

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LT1054: the device is failed