Datasheet

Digital Inputs
The digital inputs are compatible with CMOS logic.
Supply current increases slightly when toggling the
logic inputs through the transition zone between
0.3
✕
V
DD
and 0.7
✕
V
DD
.
Microprocessor Interfacing
The MAX5222 serial interface is compatible with
MICROWIRE, SPI, and QSPI. For SPI, clear the CPOL
and CPHA bits (CPOL = 0 and CPHA = 0). CPOL = 0
sets the inactive clock state to zero, and CPHA = 0
changes data at the falling edge of SCLK. This setting
allows SPI to run at full clock speeds. If a serial port is
not available on your µP, 3 bits of a parallel port can be
used to emulate a serial port by bit manipulation.
Minimize digital feedthrough at the voltage outputs by
operating the serial clock only when necessary.
MAX5222
Dual, 8-Bit, Voltage-Output
Serial DAC in 8-Pin SOT23
10 ______________________________________________________________________________________
1LSB REF 2 REF
1
256
ANALOG OUTPUT REF
D
256
8
=×=×






=×






−
Table 4. Code Table
CS
SCLK
DIN
t
DS
t
DH
t
CL
t
CH
t
CSS
t
CSPWH
t
CSH
Figure 3. Detailed Serial-Interface Timing Diagram
0V00000000
+×






REF
1
256
10000000
+×






REF
127
256
11111110
+×






=+REF
128
256
REF
2
00000001
+×






REF
129
256
10000001
+×






REF
255
256
11111111
ANALOG
OUTPUT
B0
B1B2B3B4B5B6
B7
DAC CONTENTS
Note:
where D = decimal
value of digital input