Applications information, Table 2. unipolar code table – Rainbow Electronics MAX5353 User Manual
Page 12
MAX5352/MAX5353
Low-Power, 12-Bit Voltage-Output DACs
with Serial Interface
12
______________________________________________________________________________________
Figure 7 shows a method of connecting several
MAX5352/MAX5353s. In this configuration, the clock
and the data bus are common to all devices, and sepa-
rate 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
MAX5352/MAX5353 unipolar output circuit, which is
also the typical operating circuit. Table 2 lists the unipo-
lar output codes.
Figure 9 illustrates a rail-to-rail output. This circuit
shows the MAX5352 with the output amplifier config-
ured with a closed-loop gain of +2 to provide a 0V to 5V
full-scale range when a 2.5V reference is used. When
the MAX5353 is used with a 1.25V reference, this circuit
provides a 0V to 2.5V full-scale range.
Bipolar Output
The MAX5352/MAX5353 output can be configured for
bipolar operation using Figure 10’s circuit according to
the following equation:
V
OUT
= V
REF
[(2NB / 4096) - 1]
where NB is the numeric value of the DAC’s binary input
code. Table 3 shows digital codes (offset binary) and
the corresponding output voltage for Figure 10’s circuit.
NOTE: ( ) are for sub-bit.
Using an AC Reference
In applications where the reference has AC-signal com-
ponents, the MAX5352/MAX5353 have multiplying
capability within the reference input range specifica-
tions. 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
MAX5352
MAX5353
DIN
SCLK
CS
MAX5352
MAX5353
DIN
SCLK
CS
MAX5352
MAX5353
DIN
SCLK
CS
DIN
SCLK
CS1
CS2
CS3
Figure 7. Multiple MAX5352/MAX5353s Sharing Common DIN and SCLK Lines
Table 2. Unipolar Code Table
ANALOG OUTPUT
1 1 1 1 1 1 1 1 1 1 1 1 ( 0 )
1 0 0 0 0 0 0 0 0 0 0 1 ( 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 1 1 ( 0 )
0 0 0 0 0 0 0 0 0 0 0 0 ( 0 )
0V
0 0 0 0 0 0 0 0 0 0 0 1 ( 0 )
+V
4095
4096
REF
+V
2049
4096
REF
+V
2048
4096
V
2
REF
REF
= +
+V
2047
4096
REF
+V
1
4096
REF