Rainbow Electronics MAX522 User Manual
Page 9
MAX522
Dual, 8-Bit, Voltage-Output
Serial DAC in 8-Pin SO Package
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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