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AGND

1

CON1

2

CON0

3

EXTREF

4

AIN+

5

AIN−

6

AGND

7

AVDD

8

REFT

9

REFB

10

OVRNG

11

D11

12

D10

13

D9

14

D8

15

D7

16

D6

17

D5

18

DGND

19

DVDD

20

D4

21

D3

22

D2

23

D1

24

D0

25

OE

26

CLKVDD

27

CLK

28

U1

THS1230PW

+3.3VA

+3.3VD +3.3VA

ADCCLK

OEB

CON0

CON1

EXTREF

VINP

VINM

ADCCLK

OEB

CON0

CON1

EXTREF

VINM

D4

10

D5

9

D6

8

D7

7

D8

6

D9

5

D10

4

D11

3

D12

2

D13

1

CLK

28

MODE

25

DVDD

27

DGND

26

AGND

20

AVDD

24

EXTLO

16

REFIO

17

FSADJ

18

COMP1

19

COMP2

23

IOUT1

22

IOUT2

21

SLEEP

15

D3

11

D2

12

D1

13

D0

14

U3

THS5671AIPW

LNK3

LNK2

LNK4

LNK5

R2

47K

R23

47K

R1

47K

R24

47K

+3.3VD

+3.3VD

+3.3VD

+3.3VD

OEB

EXTREF

CON1

CON0

CON0

TP1

TP2

C28

10uF

C27

0.1uF

C25

0.1uF

C26

0.1uF

VRT

VRB

VRT

VRB

C62

470pF

C63

0.1uF

C64

470pF

C65

0.1uF

C66

470pF

C67

0.1uF

+3.3VD

_3.3VA

ADCOVRNG

ADCD00

ADCD01

ADCD02

ADCD03

ADCD04

ADCD05

ADCD06

ADCD07

ADCD08

ADCD09

ADCD10

ADCD11

ADCD [00:11]

+3.3VA

+3.3VD

ADCDB00

ADCDB01

ADCDB02

ADCDB03

ADCDB04

ADCDB05

ADCDB06

ADCDB07

ADCDB08

ADCDB09

ADCDB10

ADCDB11

ADCDB[00:11]

DACCLK

DACCLK

C6

0.1uF

C15

0.1uF

+3.3VA

IOUT1

IOUT2

R10

2K

C16

0.01uF

C5

0.1uF

C19

10uF

C17

0.1uF

C18

0.1uF

+3.3VD

+3.3VA

CON1

OEB

EXTREF

IOUT1

IOUT2

+

VINP

DEFINITIONS OF SPECIFICATIONS AND TERMINOLOGY

Integral Nonlinearity (INL)

Differential Nonlinearity (DNL)

Offset and Gain Error

THS1230

SLAS291B – OCTOBER 2000 – REVISED MARCH 2004

Figure 22. EVM Schematic

Integral nonlinearity refers to the deviation of each individual code from a line drawn from zero through full scale.

The point used as zero occurs 1/2 LSB before the first code transition. The full-scale point is defined as level 1/2

LSB beyond the last code transition. The deviation is measured from the center of each particular code to the

true straight line between these two end-points.

An ideal ADC exhibits code transitions that are exactly 1 LSB apart. DNL is the deviation from this ideal value.

Therefore, this measure indicates how uniform the transfer function step sizes are. The ideal step size is defined

here as the step size for the device under test, i.e. (last transition level - first transition level)/(2n –2). Using this

definition for DNL separates the effects of gain and offset error. A minimum DNL better than –1 LSB ensures no

missing codes.

Offset error (in LSBs) is defined as the average offset for all inputs, and gain error is defined as the maximum

error (in LSBs) caused by the angular deviation from the offset corrected straight line.

17