AMC7834: Bipolar DAC is not clamping to AVss (-5V)

Marks Greulich

Part Number: AMC7834

Hi there,

have several AMCs on my board and already using them as expected. But one of them is working differently and not sure if it is damaged or what I can do.

Normally when the AMC is clamping it goes with the DAC bipolar to -5V. But at one AMC (only one of that DAC pairs) is Always going to around 0V instead. So AVss -5V is working properly cause the 2nd bipolar DAC seems to work and clamping.

The DAC itself is also working when I write the Register...I can set around -5...0V manually via SPI. So it seems it is electrically capable. But only when it gets a clamping command...it`s not.

Thanks and regards,

Markus

over 4 years ago

0 Paul_Frost over 4 years ago

TI__Guru 52683 points

Hi Markus,

I suspect one of the VCLAMPx pins are not soldered to the correct voltage. Note that the bipolar DACs use the VCLAMPx pins as pairs, so it would make sense that only 2 channels have the issue.

Thanks,

Paul

0 Marks Greulich over 4 years ago in reply to Paul_Frost

Intellectual 530 points

Hi Paul,

thanks a lot - ur were Right - the pin after Assembly was incorrect assembled and has an open!

Solved - THANKS!

Markus

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AMC7834: Bipolar DAC is not clamping to AVss (-5V)