_______________General Description
The MAX520/MAX521 are quad/octal, 8-bit voltage-output
digital-to-analog converters (DACs) with simple 2-wire ser-
ial interfaces that allow communication between multiple
devices. They operate from a single +5V supply and their
reference input range includes both supply rails.
The MAX521 includes rail-to-rail output buffer amplifiers for
reduced system size and component count when driving
loads. The MAX520’s unbuffered voltage outputs reduce
the device’s total supply current to 4µA and provide
increased accuracy at low output currents.
The MAX520/MAX521 feature a serial interface and internal
software protocol, allowing communication at data rates up
to 400kbps. The interface, combined with the double-
buffered input configuration, allows the DAC registers to be
updated individually or simultaneously. In addition, the
devices can be put into a low-power shutdown mode that
reduces supply current to 4µA. Power-on reset ensures the
DAC outputs are at 0V when power is initially applied.
The MAX520 is available in 16-pin DIP and wide SO pack-
ages, as well as a space-saving 20-pin SSOP. The
MAX521 comes in 20-pin DIP and 24-pin SO packages, as
well as a space-saving 24-pin SSOP.
________________________Applications
Minimum Component Analog Systems
Digital Offset/Gain Adjustment
Industrial Process Control
Automatic Test Equipment
Programmable Attenuators
____________________________Features
♦ Single +5V Supply
♦ Simple 2-Wire Serial Interface
♦ I
2
C Compatible
♦ Outputs Swing Rail to Rail:
Unbuffered Outputs (MAX520)
Buffered Outputs (MAX521)
♦ 1%-Accurate Trimmed Output Resistance (MAX520A)
♦ Ultra-Low 4µA Supply Current (MAX520)
♦ Individual DACs Have Separate Reference Inputs
♦ Power-On Reset Clears All Latches
♦ 4µA Power-Down Mode
MAX520/MAX521
Quad/Octal, 2-Wire Serial 8-Bit DACs
with Rail-to-Rail Outputs
________________________________________________________________
Maxim Integrated Products
1
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
OUT1
OUT2
OUT3
REF2
REF3
V
DD
AD2
AD1
AD0
OUT0
REF1
REF0
AGND
DGND
SCL
SDA
TOP VIEW
MAX520
DIP/SO
_________________Pin Configurations
INPUT
LATCH 0
8-BIT
SHIFT REGISTER
SCL REF0SDA REF1
OUTPUT
LATCH 0
DAC0
OUT0
1
MAX520
ADDRESS
COMPARATOR
START/STOP
DETECTOR
DECODE
OUTPUT
LATCH 1
DAC1
OUT1
4
8
INPUT
LATCH 2
OUTPUT
LATCH 2
DAC2
OUT2
OUT3
INPUT
LATCH 3
OUTPUT
LATCH 3
DAC3
REF3REF2AD2
AD1
AD0
1
INPUT
LATCH 1
1
1
_______________Functional Diagrams
______________Ordering Information
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
19-0378; Rev 3; 9/96
PART
†
MAX520ACPE
MAX520BCPE
MAX520ACWE 0°C to +70°C
0°C to +70°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
16 Plastic DIP
16 Plastic DIP
16 Wide SO
TUE
(LSB)
1
1
1
Pin Configurations continued at end of data sheet.
Functional Diagrams continued at end of data sheet.
MAX520BCWE 0°C to +70°C 16 Wide SO 1
Ordering Information continued at end of data sheet.
†
MAX520 “A” grade parts include a 1%-accurate, factory-trimmed
output resistance.
