TIPD135 output drop after a few minutes of measurement

rider

Other Parts Discussed in Thread: TIPD135

Hi,

I ordered two TIPD135 PCBs and performed some test measurements. Both work fine for several minutes of measurements,but the output drops after 2 to 5 minutes of measurements.
That happens also if I do not connect any input. If doing so, I see 2.54V on VOUT+ and VOUT-, but after a few minutes it drops to -0.3V and 0.3V
I supplied the board either with a regulated power supply or with 4x 9V batteries and it happens with both supplies.

Did anybody else experience that behaviour?

thanks, rider

over 9 years ago

0 Jason Bridgmon over 9 years ago

TI__Genius 14825 points

Rider,

I'm forwarding this question to the appropriate parties to assist you. Thanks for using TI products!

Best regards,

Jason Bridgmon

0 Ian Williams over 9 years ago in reply to Jason Bridgmon

TI__Mastermind 27715 points

Hi Rider,

Thank you for your interest in TIPD135. When the output voltage drops out, does the Error Flag LED illuminate?

Best regards,

Ian Williams
Linear Applications Engineer
Precision Analog - Op Amps

0 rider over 9 years ago in reply to Ian Williams

Intellectual 370 points

Hi Ian and Jason,

Thanks for your reply.

No, the Error Flag does not illuminate before the Error occurs.

I also applied a continuous sine current and again after two minutes of correct operation the ouput voltage drops (a sine wave with correct frequency is still displayed but with a much smaller amplitude). Switching power supply off and on again and everythings works fine.

Following you question about the LED, I increased the input above the rails, saw the LED illuminating everytime the output hit the rails and reached the state of output voltage drop after some seconds.

0 Ian Williams over 9 years ago in reply to rider

TI__Mastermind 27715 points

Hi Rider,

Can you tell me the current consumption of the circuit before and after the output voltage drops?

I'll test this on Wednesday when I'm back at the office.

Best regards,

Ian Williams

0 rider over 9 years ago in reply to Ian Williams

Intellectual 370 points

Hi Ian,

Before voltage drop: 3.23mA at VSP, 1.83mA at VSN

After voltage drop: 1.7mA at VSP, 1.7mA at VSN

best regards,

rider

0 rider over 9 years ago in reply to rider

Intellectual 370 points

Hi,

Do you have any news regarding the issue?

Could you reproduce the error?

best,

rider

0 Ian Williams over 9 years ago in reply to rider

TI__Mastermind 27715 points

Hello Rider,

I've been unable to reproduce the error. With no input, the board has been powered on for over 30 minutes with no errors and the output pins have remained at ~2.5V.

Best regards,

Ian Williams

Amplifiers

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TIPD135 output drop after a few minutes of measurement