MAX520 Datasheet, PDF (1/20 Pages) Maxim Integrated Products – Quad/Octal, 2-Wire Serial 8-Bit DACs with Rail-to-Rail Outputs

19-0378; Rev 3; 9/96
Quad/Octal, 2-Wire Serial 8-Bit DACs
with Rail-to-Rail Outputs
_______________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
_________________Pin Configurations
TOP VIEW
OUT1 1
OUT0 2
REF1 3
REF0 4
AGND 5
DGND 6
SCL 7
SDA 8
MAX520
16 OUT2
15 OUT3
14 REF2
13 REF3
12 VDD
11 AD2
10 AD1
9 AD0
DIP/SO
Pin Configurations continued at end of data sheet.
____________________________Features
o Single +5V Supply
o Simple 2-Wire Serial Interface
o I²C Compatible
o Outputs Swing Rail to Rail:
Unbuffered Outputs (MAX520)
Buffered Outputs (MAX521)
o 1%-Accurate Trimmed Output Resistance (MAX520A)
o Ultra-Low 4µA Supply Current (MAX520)
o Individual DACs Have Separate Reference Inputs
o Power-On Reset Clears All Latches
o 4µA Power-Down Mode
______________Ordering Information
PART^†
MAX520ACPE
MAX520BCPE
MAX520ACWE
MAX520BCWE
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
16 Plastic DIP
16 Plastic DIP
16 Wide SO
16 Wide SO
TUE
(LSB)
1
1
1
1
Ordering Information continued at end of data sheet.
†_{MAX520 “A” grade parts include a 1%-accurate, factory-trimmed}
output resistance.
_______________Functional Diagrams
SDA SCL
MAX520
8-BIT ⁸
SHIFT REGISTER
ADDRESS
COMPARATOR
START/STOP
DETECTOR
REF1
INPUT
LATCH 0
1
OUTPUT
LATCH 0
REF0
DAC0 ^OUT0
INPUT
LATCH 1
1
OUTPUT
LATCH 1
DAC1 OUT1
DECODE
4
INPUT
LATCH 2
1
OUTPUT
LATCH 2
DAC2 ^OUT2
INPUT OUTPUT
LATCH 3 LATCH 3
DAC3 ^OUT3
1
AD0
AD2
AD1
REF2
REF3
Functional Diagrams continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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