MAX535 Maxim, MAX535 Datasheet - Page 13

• Manufacturer Part Number: MAX535
• Description: Low-Power / 13-Bit Voltage-Output DACs with Serial Interface
• Manufacturer: Maxim

Table 3. Bipolar Code Table
Figure 8. Unipolar Output Circuit
1 1 1 1 1
1 0 0 0 0
1 0 0 0 0
0 1 1 1 1
0 0 0 0 0
0 0 0 0 0
MSB
MAX5351
MAX535
DAC CONTENTS
1 1 1 1
0 0 0 0
0 0 0 0
1 1 1 1
0 0 0 0
0 0 0 0
REF
______________________________________________________________________________________
Low-Power, 13-Bit Voltage-Output DACs
LSB
1 1 1 1
0 0 0 1
0 0 0 0
1 1 1 1
0 0 0 1
0 0 0 0
DAC
-V
ANALOG OUTPUT
REF
V
DD
+V
+V
-V
-V
+5V/+3.3V
REF
REF
REF
REF
4096
4096
GND
0V
4096
4095
4096
4095
4096
4096
1
1
FB
- V
OUT
REF
The MAX535’s total harmonic distortion plus noise (THD
+ N) is typically less than -77dB (full-scale code), and
the MAX5351’s THD + N is typically less than -72dB
(full-scale code), given a 1Vp-p signal swing and input
frequencies up to 25kHz. The typical -3dB frequency is
650kHz for both devices, as shown in the Typical
Operating Characteristics graphs.
The circuit of Figure 12 places an NPN transistor
(2N3904 or similar) within the op-amp feedback loop to
implement a digitally programmable, unidirectional cur-
rent source. This circuit can be used to drive 4–20mA
current loops, which are commonly used in industrial-
control applications. The output current is calculated
with the following equation:
where NB is the numeric value of the DAC’s binary
input code and R is the sense resistor shown in
Figure 12.
Figure 9. Unipolar Rail-to-Rail Output Circuit
MAX5351
MAX535
Digitally Programmable Current Source
with Serial Interface
I
OUT
REF
DAC
= (V
REF
/ R) x (NB / 8192)
V
DD
+5V/+3.3V
GND
FB
OUT
10k
10k
13