Clock line should be short

and cross no other lines.

Single Ground entry for all

Reference Components

All Analog Components

mounted over Analog

area of Ground Plane

Xfmr/Amplifier

Components

mounted over

Digital area of

Digital power line should be routed

away from analog power trace.

COMMON

GROUND

PLANE

Ground entry points

close to ground pins.

Analog power line should be routed

away from Digital power trace.

Driving source

located close

to converter.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

V

D

DB5

DB4

DB3

DB2

DB1

DB0

OEB/DRDY

DR GND

DA11

DA10

DA9

DA8

DA7

DA6

V

D

VIN B-

VIN B+

AGND

V

RMB

V

RPB

V

RNB

V

REF

AGND

V

A

AGND

REFSEL/DCS

V

RNA

V

RPA

V

RMA

VIN A+

VIN A-

ADC12DL080

All Digital

Ground Plane

6 x 100:

6 x 100:

OSC

LATCH

LATCH

ADC12DL080

www.ti.com

SNAS345A – FEBRUARY 2006 – REVISED APRIL 2013

Figure 45. Example of a Suitable Layout

Be especially careful with the layout of inductors. Mutual inductance can change the characteristics of the circuit

in which they are used. Inductors should not be placed side by side, even with just a small part of their bodies

beside each other.

The analog input should be isolated from noisy signal traces to avoid coupling of spurious signals into the input.

Any external component (e.g., a filter capacitor) connected between the converter's input pins and ground or to

the reference input pin and ground should be connected to a very clean point in the ground plane.

Figure 45 gives an example of a suitable layout. All analog circuitry (input amplifiers, filters, reference

components, etc.) should be placed in the analog area of the board. All digital circuitry and I/O lines should be

placed in the digital area of the board. The ADC12DL080 should be between these two areas. Furthermore, all

components in the reference circuitry and the input signal chain that are connected to ground should be

connected together with short traces and enter the ground plane at a single, quiet point. All ground connections

should have a low inductance path to ground.

Copyright © 2006–2013, Texas Instruments Incorporated

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