MAX5156 Maxim, MAX5156 Datasheet - Page 14

• Manufacturer Part Number: MAX5156
• Description: Low-Power / Dual / 12-Bit Voltage-Output DACs with Configurable Outputs
• Manufacturer: Maxim

In applications where the reference has an AC signal
component, the MAX5156/MAX5157 have multiplying
capabilities within the reference input voltage range
specifications. Figure 12 shows a technique for apply-
ing a sinusoidal input REF_, where the AC signal is off-
set before being applied to the reference input.
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Configurable Outputs
Figure 10. Configurable Output Gain
Table 3. Bipolar Code Table
Note: ( ) are for the sub bit.
14
1 1 1 1
1 0 0 0
1 0 0 0
0 1 1 1
0 0 0 0
0 0 0 0
MSB
______________________________________________________________________________________
DAC CONTENTS
V
OUT
REF_
1 1 1 1
0 0 0 0
0 0 0 0
1 1 1 1
0 0 0 0
0 0 0 0
=
(
1 + R1
DAC
MAX5156
MAX5157
R2
) (
DGND
1 1 1 1 ( 0 )
0 0 0 1 ( 0 )
0 0 0 0 ( 0 )
1 1 1 1 ( 0 )
0 0 0 1 ( 0 )
0 0 0 0 ( 0 )
4096
N
LSB
)(
V
REF_
+5V/+3V
Using an AC Reference
V
)
DD
AGND
-V
ANALOG OUTPUT
REF
+V
+V
-V
-V
REF
REF
REF
REF
2048
2098
FB_
OUT_
0V
2048
2048
2047
2048
2047
2048
1
1
R2
R1
- V
REF
V
OUT
The total harmonic distortion plus noise (THD+N) is typ-
ically less than -80dB at full scale with a 1Vp-p input
swing at 5kHz. The typical -3dB frequency is 600kHz
for both devices, as shown in the Typical Operating
Characteristics .
Figure 11. Bipolar Output Circuit
Figure 12. AC Reference Input Circuit
REFERENCE
REF_
500mVp-p
+5V/
+3V
INPUT
DAC _
AC
MAX5156
MAX5157
26k
DGND
+5V/+3V
10k
V
Harmonic Distortion and Noise
DD
+5V/+3V
AGND
DGND
DAC_
FB_
OUT_
REF_
MAX495
10k
MAX5156
MAX5157
AGND
V
DD
10k
V+
V-
FB_
OUT_
V
OUT