Rainbow Electronics MAX5304 - Manual (Page 9)

MAX5304
10-Bit Voltage-Output DAC
in 8-Pin µMAX
_______________________________________________________________________________________ 9
Figure 7 shows a method of connecting several
MAX5304s. In this configuration, the clock and the data
bus are common to all devices, and separate chip-
select lines are used for each IC.
Applications Information
Unipolar Output
For a unipolar output, the output voltage and the refer-
ence input have the same polarity. Figure 8 shows the
MAX5304 unipolar output circuit, which is also the typi-
cal operating circuit. Table 2 lists the unipolar output
codes.
Figure 9 illustrates a Rail-to-Rail ® output configuration.
This circuit shows the MAX5304 with the output amplifi-
er configured for a closed-loop gain of +2V/V to provide
a 0 to 5V full-scale range when a 2.5V reference is used.
Bipolar Output
The MAX5304 output can be configured for bipolar
operation using Figure 10’s circuit according to the fol-
lowing equation:
V OUT = V REF [(2NB / 1024) - 1]
where NB is the numeric value of the DAC’s binary
input code. Table 3 shows digital codes (offset binary)
and corresponding output voltages for Figure 10’s cir-
cuit.
Using an AC Reference
In applications where the reference has AC signal com-
ponents, the MAX5304 has multiplying capability within
the reference input range specifications. Figure 11
shows a technique for applying a sine-wave signal to
the reference input where the AC signal is offset before
being applied to REF. The reference voltage must
never be more negative than GND.
TO OTHER
SERIAL DEVICES
MAX5304
DIN
SCLK
CS
MAX5304
DIN
SCLK
MAX5304
DIN
SCLK
DIN
SCLK
CS1
CS2
CS3
CS CS
Figure 7. Multiple MAX5304s Sharing Common DIN and SCLK Lines
Table 2. Unipolar Output Codes
Note: ( ) are for sub-bits.
ANALOG OUTPUT
1 1 1 1 1 1 1 1 1 1 ( 0 0 0 )
1 0 0 0 0 0 0 0 0 1 ( 0 0 0 )
DAC CONTENTS
MSB LSB
1 0 0 0 0 0 0 0 0 0 ( 0 0 0 )
0 1 1 1 1 1 1 1 1 1 ( 0 0 0 )
0 0 0 0 0 0 0 0 0 0 ( 0 0 0 ) 0V
0 0 0 0 0 0 0 0 0 1 ( 0 0 0 )
+V
1023
1024
REF

 

+V
513
1024
REF

 

+V
512
1024
V
2
REF
REF

 

=
+
+V
511
1024
REF

 

+V
1
1024
REF

 

Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.