AMC1035-Q1: Reference voltage

Saraswathy G

Prodigy 80 points

Part Number: AMC1035-Q1
Other Parts Discussed in Thread: AMC1035,

What is the reference voltage to be considered for error/accuracy calculation? Is it 1.25V (clipping voltage) or 2.5V?

5 months ago

0 Tom Hendrick 5 months ago

TI__Guru**** 171786 points

Hi Saraswathy,

You need to use the clipping voltage level = +/-1.25, which is in the end 2.5V.

0 Saraswathy G 5 months ago in reply to Tom Hendrick

Prodigy 80 points

OK, so this means 1LSB = 1.25V/(2^n-1). (n=16 bit)

How do we compute the gain and offset errors for AMC1035. I see the values are given in the datasheet on errors and their thermal drift. But is gain error considered as a multiplying factor or is it just added with other errors to compute the net error.

Do you have any reference documents that explains the error estimation using AMC1035-Q1. Pls support on this.

0 Saraswathy G 5 months ago in reply to Tom Hendrick

Prodigy 80 points

But on this thread,- (+) AMC1035: offset and refernece - Data converters forum - Data converters - TI E2E support forums , the reference voltage is said to be 2.5V. Pls clarify this again.

0 Tom Hendrick 5 months ago in reply to Saraswathy G

TI__Guru**** 171786 points

As I said in my initial reply, you need to use the clipping voltage which is +/-1.25V. From -1.25 to +1.25, the input range is 2.5V, which is what you found in the other forum post. Gain error is a multiply factor, offset is additive. There is a video explaining gain and offset errors here: https://www.ti.com/video/series/precision-labs/ti-precision-labs-analog-to-digital-converters-adcs.html

Look for "Understanding and calibrating the offset and gain for ADC systems" under the Error sources topic.