AD660

REV. A

–12–

GROUNDING

The AD660 has two pins, designated analog ground (AGND)

and digital ground (DGND.) The analog ground pin is the

“high quality” ground reference point for the device. Any exter-

nal loads on the output of the AD660 should be returned to

analog ground. If an external reference is used, this should also

be returned to the analog ground.

If a single AD660 is used with separate analog and digital

ground planes, connect the analog ground plane to AGND and

the digital ground plane to DGND keeping lead lengths as short

as possible. Then connect AGND and DGND together at the

AD660. If multiple AD660s are used or the AD660 shares ana-

log supplies with other components, connect the analog and

digital returns together once at the power supplies rather than at

each chip. This single interconnection of grounds prevents large

ground loops and consequently prevents digital currents from

flowing through the analog ground.

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

N-24

24-Lead Plastic DIP

0.210

(5.33)

MAX

0.022 (0.558)

0.014 (0.356)

0.100

(2.54)

BSC

PIN 1

0.325 (8.25)

0.300 (7.62)

0.015 (0.381)

0.008 (0.204)

0.195 (4.95)

0.115 (2.93)

0.070 (1.77)

0.045 (1.15)

SEATING

PLANE

0.060 (1.52)

0.015 (0.38)

0.280 (7.11)

0.240 (6.10)

0.200 (5.05)

0.125 (3.18)

0.150

(3.81)

MIN

1.275 (32.30)

1.125 (28.60)

2

4

1

13

12

Q-24

24-Lead Cerdip

0.320 (8.13)

0.290 (7.37)

0.015 (0.38)

0.008 (0.20)

15

°

0

°

1.060 (26.92) MAX

0.200

(5.08)

MAX

0.023 (0.58)

0.014 (0.36)

0.200 (5.08)

0.125 (3.18)

0.100

(2.54)

BSC

0.070 (1.78)

0.030 (0.76)

0.060 (1.52)

0.015 (0.38)

0.150

(3.81)

MIN

SEATING

PLANE

0.005 (0.13) MIN

PIN 1

1

2

4

0.098 (2.49) MAX

0.310 (7.87)

0.220 (5.59)

12

1

3

R-24

24-Lead Small Outline (SOIC)

0.0125 (0.32)

0.0091 (0.23)

0.0500 (1.27)

0.0157 (0.40)

8

°

0

°

0.0291 (0.74)

PIN 1

0.2992 (7.60)

0.2914 (7.40)

0.4193 (10.65)

0.3937 (10.00)

13

12

1

24

0.0192 (0.49)

0.0138 (0.35)

0.0500

(1.27)

BSC

0.1043 (2.65)

0.0926 (2.35)

0.6141 (15.60)

0.5985 (15.20)

0.0118 (0.30)

0.0040 (0.10)