max5742 Maxim Integrated Products, Inc., max5742 Datasheet - Page 11

• Manufacturer Part Number: max5742
• Description: Max5742 12-bit, Low-power, Quad, Voltage-output Dac With Serial Interface
• Manufacturer: Maxim Integrated Products, Inc.

The typical application circuit (Figure 3) shows the
MAX5742 configured for a unipolar output, where the
output voltages and the reference inputs have the
same polarity. Table 3 lists the unipolar output codes.
The MAX5742 can be configured for bipolar operation
using a dual supply op amp (Figure 4). The transfer
function for bipolar operation is:
Figure 1. 16-Bit Input Word
Figure 2. Timing Diagram
D15 (MSB)
C3
CONTENTS OF SHIFT REGISTER
SCLK
DIN
CS
C2
t
X
X
CSPWH
V
Applications Information
OUT
12-Bit, Low-Power, Quad, Voltage-Output
C1
______________________________________________________________________________________
V
t
t
CSS
OS
REF
1
C0
C3
t
OH
4096
2NB
D11
2
Unipolar Output
C2
Bipolar Output
t
D10
1
CL
t
CH
3
C1
D9
D8
4
DAC with Serial Interface
C0
where NB is the decimal value of the DACs binary input
code. Table 4 shows digital codes (offset binary) and
corresponding output voltages for the circuit in Figure 4.
Careful PC board layout is important for optimal system
performance. To reduce noise injection and digital feed-
through, keep analog and digital signals separate.
Ensure that that the return path from GND to the supply
ground is short and low impedance. Use a ground
plane. Bypass V
close as possible to V
D7
Power Supply and Layout Considerations
5
D11
D6
6
D5
D10
DD
to GND with a 0.1µF capacitor as
DD
D4
.
D1
D3
16
D0
D2
t
CSH
X
D1
D0 (LSB)
X
D0
11