Dual, 8-Bit, Voltage-Output

Serial DAC in 8-Pin SO Package

_______________________________________________________________________________________

9

DIN

SCLK

CS

UB1 UB2 UB3

SB

SA

UB4

LB

LA

D7

D6

D5

D4

D3

D2

D1

D0

OPTIONAL

INSTRUCTION

EXECUTED

(CONTROL BYTE)

(DATA BYTE)

Figure 2. MAX522 3-Wire Serial-Interface Timing Diagram

Table 2. Serial-Interface Programming Commands

Table 3. Example of a 16-Bit Input Word

X =

Don’t care.

* = Not shown, for the sake of clarity. The functions of loading and shutting down the DACs and programming the logic can be combined in a single

command.

X

X

1

0

0

0

1

1

1

0

0

0

0

0

0

0

UB1

UB2

UB3

SB

SA

UB4

LB

LA

B7

B6

B5

B4

B3

B2

B1

B0

Loaded

Loaded

in First

in Last

CONTROL

*

1

1

*

0

X

X

1

X

0

*

1

1

X

X

X

X

X

0

*

0

1

0

0

1

0

0

1

B6

B5

Shut Down All DACs

X

X

X

X

X

X

X

X

*

*

0

1

1

1

X

X

Shut Down DAC A

X

X

X

X

X

X

X

X

*

*

0

1

0

1

X

X

Shut Down DAC B

X

X

X

X

X

X

X

X

*

*

0

0

1

1

X

X

Unassigned Command

X

X

X

X

X

X

X

X

*

*

0

0

0

1

X

X

All DACs Active

X

X

X

X

X

X

X

X

*

*

0

0

0

1

X

X

Load Both DAC Registers

8-Bit DAC Data

*

Load Register to DAC A

8-Bit DAC Data

*

Load Register to DAC B

8-Bit DAC Data

*

Unassigned Command

*

No Operation to DAC Registers

X

X

X

X

X

X

X

X

0

0

0

*

*

1

X

X

FUNCTION

B0

LSB

B1

B2

B3

B4

B7

MSB

LA

LB

UB4

SA

SB

UB3

UB2

UB1

DATA