–12–

AD5541/AD5542

REV. A

APPLICATIONS

Optocoupler interface

The digital inputs of the AD5541/AD5542 are Schmitt-

triggered, so they can accept slow transitions on the digital input

lines. This makes these parts ideal for industrial applications

where it may be necessary that the DAC is isolated from the

controller via optocouplers. Figure 25 illustrates such an interface.

SCLK

DIN

CS

AD5541/AD5542

DIN

CS

SCLK

POWER

5V

REGULATOR

GND

10 F

10k

10k

10k

0.1 F

Figure 25. AD5541/AD5542 in an Optocoupler Interface

Decoding Multiple AD5541/AD5542s

The CS pin of the AD5541/AD5542 can be used to select one

of a number of DACs. All devices receive the same serial clock

and serial data, but only one device will receive the CS signal at

any one time. The DAC addressed will be determined by the

decoder. There will be some digital feedthrough from the digital

input lines. Using a burst clock will minimize the effects of digi-

tal feedthrough on the analog signal channels. Figure 26 shows a

typical circuit.

ENABLE

DIN

SCLK

DGND

CODED

ADDRESS

DECODER

EN

AD5541/AD5542

CS

DIN

SCLK

AD5541/AD5542

CS

DIN

SCLK

AD5541/AD5542

CS

DIN

SCLK

AD5541/AD5542

CS

DIN

SCLK

Figure 26. Addressing Multiple AD5541/AD5542s

14-Lead SO

(R-14)

14

8

7

1

0.2440 (6.20)

0.2284 (5.80)

0.1574 (4.00)

0.1497 (3.80)

PIN 1

0.3444 (8.75)

0.3367 (8.55)

0.050 (1.27)

BSC

SEATING

PLANE

0.0098 (0.25)

0.0040 (0.10)

0.0192 (0.49)

0.0138 (0.35)

0.0688 (1.75)

0.0532 (1.35)

8

0

0.0196 (0.50)

0.0099 (0.25)

45

0.0500 (1.27)

0.0160 (0.41)

0.0099 (0.25)

0.0075 (0.19)

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

8-Lead SO

(SO-8)

85

4

1

0.1968 (5.00)

0.1890 (4.80)

0.2440 (6.20)

0.2284 (5.80)

PIN 1

0.1574 (4.00)

0.1497 (3.80)

0.0500 (1.27)

BSC

0.0688 (1.75)

0.0532 (1.35)

SEATING

PLANE

0.0098 (0.25)

0.0040 (0.10)

0.0192 (0.49)

0.0138 (0.35)

0.0098 (0.25)

0.0075 (0.19)

0.0500 (1.27)

0.0160 (0.41)

8

0

0.0196 (0.50)

0.0099 (0.25)

45