AMC1100: Offset output voltage at 0V input issue

elmarto

Part Number: AMC1100

Hi all,

While trying to use the AMC1100DWV as a current sensor I saw that in several units the output voltage while v_in = 0V exceeds +/-25 mV depending on the sample. ¿Is it OK? I am attaching the acquisition part of the schematic to take a look.

It looks like it is too much. but I would like to confirm that there is no bug in the schematic.

Best regards,

Martín

over 5 years ago

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Elmarto,

what is BH1?

Kai

0 elmarto over 5 years ago in reply to kai klaas69

Prodigy 50 points

BH is an internal designator to name a net tie for ground. It allows to tie to nets at a specific point in the layout. For the sake of this analysis it is just GND

0 Tom Hendrick over 5 years ago

TI__Guru**** 168445 points

Hi Elmarto,

When you have 0V in, are you actually sorting the inputs of the AMC1100, or just not applying any signal?

0 elmarto over 5 years ago in reply to Tom Hendrick

Prodigy 50 points

Tom,

It is not an actual short between the inputs. But VIN_P is connected to VIN_M thru ~12_Ohms.

Thanks in advance,

Martín

0 elmarto over 5 years ago in reply to elmarto

Prodigy 50 points

To add up to my response: The measured input voltage in this situation (no input voltage) is 0V.

0 Tom Hendrick over 5 years ago in reply to elmarto

TI__Guru**** 168445 points

Great! Try taking a couple more measurements - short pins 2 and 3 together, short between TP8 and TP9 and see if there is any difference. Also, are you measuring the output deferentially or VOUTp to GND2 and VOUTn to GND2?

0 Tom Hendrick over 5 years ago in reply to Tom Hendrick

TI__Guru**** 168445 points

Hi Martin,

How are you making out here?

0 Tom Hendrick over 5 years ago in reply to Tom Hendrick

TI__Guru**** 168445 points

Hi Martin,

Closing this post for now. If you have any additional feedback, please feel free to post it here.

Amplifiers

Amplifiers forum

AMC1100: Offset output voltage at 0V input issue