Data Sheet

AD5544/AD5554

Rev. H | Page 9 of 24

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

28

27

26

25

24

23

22

21

20

19

18

17

16

15

1

2

3

4

5

6

7

8

9

10

11

12

13

14

AD5544/

AD5554

TOP VIEW

(Not to Scale)

MSB

DGND

CLK

SDO

SDI

DNC

DNC = DO NOT CONNECT. LEAVE THE PIN UNCONNECTED.

LDAC

CS

RS

Figure 5. TSSOP Pin Configuration

NOTES

1. DNC = DO NOT CONNECT.

LEAVE THE PIN UNCONNECTED.

2. CONNECT THE EXPOSED PAD TO AGNDx.

22 DGND

19 LDAC

18 SDO

1

2

3

4

5

6

7

8

MSB

RS

CS

CLK

SDI

AD5544

TOP VIEW

(Not to Scale)

Figure 6. LFCSP Pin Configuration

Table 4. Pin Function Descriptions

TSSOP

Pin No.

LFCSP

Pin No.

Mnemonic

Description

1

29

A

DAC A Analog Ground.

2

30

I

DAC A Current Output.

3

32

V

DAC A Reference Voltage Input Terminal. Establishes DAC A full-scale output voltage. This pin can

be tied to the V

4

1

R

DAC A Feedback Resistor Connection. Establish the voltage output for DAC A by connecting this pin

to an external amplifier output.

5

2

MSB

6

3

RS

Reset Pin, Active Low Input. Input registers and DAC registers are set to all 0s or half-scale code

(0x8000 for the AD5544 and 0x2000 for the AD5554), determined by the voltage on the MSB pin.

Register data = 0x0000 when MSB = 0.

7

4

V

DD

Positive Power Supply Input. Specified range of operation: 5 V ± 10%.

8

5

CS

Chip Select, Active Low Input. Disables shift register loading when high. Transfers serial register

data to the input register when CS/LDAC returns high. Does not affect LDAC operation.

9

6

CLK

Clock Input. Positive edge clocks data into the shift register.

10

7

SDI

Serial Data Input. Input data loads directly into the shift register.

11

8

R

DAC B Feedback Resistor Connection. Establish the voltage output for DAC B by connecting this pin

to an external amplifier output.

12

10

V

DAC B Reference Voltage Input Terminal. Establishes DAC B full-scale output voltage. This pin can be

tied to the V

13

11

I

DAC B Current Output.

14

12

A

DAC B Analog Ground.

15

13

A

DAC C Analog Ground.

16

14

I

DAC C Current Output.

17

15

V

DAC C Reference Voltage Input Terminal. Establishes DAC C full-scale output voltage. This pin can

be tied to the V

18

17

R

DAC C Feedback Resistor Connection. Establish the voltage output for DAC C by connecting this pin

to an external amplifier output.

19

9, 16, 25,

26, 31

DNC

Do Not Connect. Leave these pins unconnected.

20

18

SDO

Serial Data Output. Input data loads directly into the shift register. Data appears at SDO at 19 clock

pulses for the AD5544 and 17 clock pulses for the AD5554 after input at the SDI pin.

21

19

LDAC

Load DAC Register Strobe, Level Sensitive Active Low. Transfers all input register data to DAC

registers. Asynchronous active low input. See Table 8 and Table 9 for operation.