ADS1248: ADS1248 INL

SHREYAS S BAGI

Part Number: ADS1248
Other Parts Discussed in Thread: ADS125H02

Hi,

I have connected AVDD=5V and DVDD=5V. I wanted to know INL in terms of LSB value. Conversion of INL from ppm to in terms of LSB.

VREF = AVDD.

FSR = (2 * VREF)/Gain. = (2*5)/1 = 10

Calculation of INL interms of LSB value.

over 4 years ago

0 Alexander Smith over 4 years ago

TI__Mastermind 47595 points

Hi Shreyas,

It's worth noting that a reference voltage of 5V is outside of the range of the device. For this calculation I'll use the internal reference voltage of 2.048V.

ppm is parts per million, so you can think of 6ppm as being equal to 6/1000000 of the FSR. The FSR in this case is 2*VREF. which is 4.096V.

So 6ppm is equal to 24.576uV; 6*FSR/1000000 = 24.576uV

1 LSB = (2 x VREF)/ Gain / (2^24 - 1) = (2 x 2.048)/1/(2^24-1) = 0.244uV

24.576uV/0.244uV = 101 bits

0 SHREYAS S BAGI over 4 years ago in reply to Alexander Smith

Intellectual 400 points

Hi Alexander Smith,

You mean to say that INL level of ADS12H02 is 101LSB.

What is the min level for INL in ADC devices.?

0 Alexander Smith over 4 years ago in reply to SHREYAS S BAGI

TI__Mastermind 47595 points

Hi Shreyas,

Yes, the INL equivalent of 6ppm for the ADS1248 with a 2.048V reference is 101LSB.

The minimum INL for an ADC would be 0ppm.

0 Bob Benjamin over 4 years ago in reply to SHREYAS S BAGI

TI__Guru** 112765 points

Hi Shreyas,

Just so we are clear here, the original discussion started with the ADS1248 and the response was specific for the ADS1248. The ADS125H02 has different specs for INL, so not all ADCs have the same specifications. You would need to check the Electrical Characteristics table for each ADC and compare.

Best regards,

Bob B

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ADS1248: ADS1248 INL