AMC1100: Lower Accuracy on AMC1100

Muthu S

Part Number: AMC1100

Dea rSir,

We are evaluating AMC1100DWVR and request your support to improve the linear measurable range.

Currently we are getting the below accuracies.

Voltage Range	Accuracy
100 - 200	+/-1
200 - 300	-5
300 - 600	-15
600 - 800	-30

Regards,

Muthu S

over 6 years ago

0 kai klaas69 over 6 years ago

Guru 140200 points

Hi Muthu,

in your table the units are missing.

Can you show a schematic of your AMC1100 circuit?

Kai

0 Alexander Smith over 6 years ago in reply to kai klaas69

TI__Guru 56222 points

Hi Muthu,

Has this been resolved?

0 Muthu S over 6 years ago in reply to Alexander Smith

Intellectual 720 points

Hi Smith,

Not yet. Awaiting for end customer schematic file for review.

Regards,

Muthu S

0 Muthu S over 6 years ago in reply to Muthu S

Intellectual 720 points

Hi Smith,

Please refer the schematic and share your feedback. Issue not resolved yet.

Regards,

Muthu S

0 kai klaas69 over 6 years ago in reply to Muthu S

Guru 140200 points

Hi Muthu,

is there a direct connection between VDC- and GND as shown in figure 33 of datasheet?

Kai

0 Muthu S over 6 years ago in reply to kai klaas69

Intellectual 720 points

Hi Kai,

Yes. it is direct connection of -VDC and GND.

Regards,

Muthu S

0 Alexander Smith over 6 years ago in reply to Muthu S

TI__Guru 56222 points

Hi Muthu,

The input impedance of the AMC1100 is relatively low for voltage sensing applications.

There are two things that can be done to improve the accuracy. A calibration can be performed, or the resistors in the voltage divider circuit can be scaled down.

For clarification, please see 5. from the design steps section of this paper: http://www.ti.com/lit/an/sbaa321/sbaa321.pdf

0 kai klaas69 over 6 years ago in reply to Muthu S

Guru 140200 points

Hi Muthu,

how do you measure the accuracy? Do you connect additional circuitry to the output of AMC1100 for this? A differential OPAmp circuit or similar?

Kai

0 Muthu S over 6 years ago in reply to kai klaas69

Intellectual 720 points

Hi Kai,

Input Voltage across VDC+ and VDC- is measured and compared with the voltage across RA0 and RA1 multiplied by gain.

No additional circuitry or differential amplifier is used at the output of AMC1100.

Regards,

Muthu S

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AMC1100: Lower Accuracy on AMC1100