REV. A

AD7716

–16–

Multibandwidth System

Some applications may require multiple AD7716’s with differ-

ent bandwidths programmed to each device. The best way to

accomplish this is shown in Figure 12. The master mode inter-

face is used for this example but the slave mode may also be

used. The example shows an 8-channel system with Device #0

in the system programmed for a 292 Hz cutoff frequency and

Device #1 programmed for a 146 Hz cutoff frequency.

CASCIN

DRDY

RESET

CASCOUT

MODE

#0

(292 Hz)

CASCIN

DRDY

RESET

MODE

#1

(146 Hz)

RESET

TFS

RFS

SCLK

SDATA

Figure 12. Multibandwidth System

The resultant output signals are also shown. Since Device #0

has a higher bandwidth it will also have a higher update rate.

The receiving processor will be getting samples from this device

at twice the rate of Device #1.

#0

#0 #1

#0

#0 #1

#0

#0 #1

RESET

DRDY #0

DRDY #1

SDATA

Figure 13. Output Signals for Figure 12

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

44-Lead PLCC

(P-44A)

0.032 (0.81)

0.026 (0.66)

0.021 (0.53)

0.013 (0.33)

0.056 (1.42)

0.042 (1.07)

0.025 (0.63)

0.015 (0.38)

0.180 (4.57)

0.165 (4.19)

0.63 (16.00)

0.59 (14.99)

0.110 (2.79)

0.085 (2.16)

0.040 (1.01)

0.025 (0.64)

0.050

(1.27)

BSC

0.656 (16.66)

0.650 (16.51)

SQ

0.695 (17.65)

0.685 (17.40)

SQ

0.048 (1.21)

0.042 (1.07)

0.048 (1.21)

0.042 (1.07)

40

6

TOP VIEW

39

29

18

17

PIN 1

IDENTIFIER

7

28

0.020

(0.50)

R

44-Lead Plastic Quad Flatpack

(S-44)

0.083 (2.11)

0.077 (1.96)

0.016 (0.41)

0.012 (0.30)

0.033 (0.84)

0.029 (0.74)

1

44

34

33

23

22

12

11

TOP VIEW

PIN 1

0.398 (10.11)

0.390 (9.91)

0.557 (14.148)

0.537 (13.640)

0.096 (2.44)

MAX

0.037 (0.94)

0.025 (0.64)

0.398 (10.11)

0.390 (9.91)

0.040 (1.02)

0.032 (0.81)

0.040 (1.02)

0.032 (0.81)

8

°

0.8

°