Data Sheet

ADA8282

Rev. 0 | Page 15 of 21

MULTIPLEXING INPUTS USING MULTIPLE

ADA8282 DEVICES

It is possible to multiplex eight differential inputs down to four

differential outputs by using two ADA8282 devices. The devices

can be connected such that the outputs are connected (see

Figure 29) as long as only one device is enabled at a time. When

an ADA8282 is disabled, the outputs present a 6 kΩ load on the

output bus.

24

+OUTA

23

–OUTA

22

+OUTB

21

–OUTB

20

+OUTC

19

–OUTC

18

+OUTD

17

–OUTD

1

2

3

4

5

6

7

8

+INA

–INA

+INB

–INB

+INC

–INC

+IND

–IND

ADA8282

EPAD TIED

TO GROUND

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

INPUT A

SOURCE

INPUT B

SOURCE

INPUT C

SOURCE

INPUT D

SOURCE

0.1µF

0.1µF

0.1µF

0.1µF

+3.3V

+3.3V

+3.3V

GPIO: +3.3V/0V

+3.3V

10kΩ

SPI BUS

24

+OUTA

23

–OUTA

22

+OUTB

21

–OUTB

20

+OUTC

19

–OUTC

18

+OUTD

17

–OUTD

1

2

3

4

5

6

7

8

+INA

–INA

+INB

–INB

+INC

–INC

+IND

–IND

ADA8282

EPAD TIED

TO GROUND

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

INPUT E

SOURCE

INPUT F

SOURCE

INPUT G

SOURCE

INPUT H

SOURCE

0.1µF

0.1µF

0.1µF

0.1µF

+3.3V

+3.3V

+3.3V

GPIO: +3.3V/0V

+3.3V

10kΩ

SPI BUS

TO ADC

TO ADC

TO ADC

TO ADC

Figure 29. Multiplexing by Connecting Two ADA8282 Outputs to One Output Bus