MAX5304 Maxim, MAX5304 Datasheet - Page 10

• Manufacturer Part Number: MAX5304
• Description: 10-Bit Voltage-Output DAC in 8-Pin MAX
• Manufacturer: Maxim

10-Bit Voltage-Output DAC
in 8-Pin µMAX
Table 3. Bipolar Output Codes
Note: ( ) are for sub-bits.
Figure 8. Unipolar Output Circuit
10
MSB
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 )
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 1 ( 0 0 0 )
0 0 0 0 0 0 0 0 0 0 ( 0 0 0 )
______________________________________________________________________________________
DAC CONTENTS
REF
DAC
MAX5304
LSB
+5V
V
DD
ANALOG OUTPUT
-V
REF
GND
+V
+V
-V
-V
REF
REF
REF
REF



512
512
0V












512
511
512
512
512
511

 =

FB
OUT
1
1












- V
REF
The MAX5304’s total harmonic distortion plus noise
(THD+N) is typically less than -77dB (full-scale code),
given a 1Vp-p signal swing and input frequencies up to
25kHz. The typical -3dB frequency is 650kHz, as
shown in the Typical Operating Characteristics graphs.
Figure 12’s circuit places an NPN transistor (2N3904 or
similar) within the op amp feedback loop to implement
a digitally programmable, unidirectional current source.
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
Digitally Programmable Current Source
I
OUT
REF
= (V
DAC
MAX5304
REF
/ R)(NB / 1024)
+5V
V
DD
GND
FB
OUT
10k
10k