MAX5130 Maxim Integrated Products, MAX5130 Datasheet - Page 9

• Manufacturer Part Number: MAX5130
• Description: (MAX5130 / MAX5131) Voltage-output DACs
• Manufacturer: Maxim Integrated Products

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The MAX5130/MAX5131 13-bit, voltage-output DACs
are easily configured with a 3-wire serial interface. They
include a 16-bit data-in/data-out shift register and have
a double-buffered input consisting of an input register
and a DAC register. In addition, these devices employ
precision bandgap references and trimmed internal
resistors to produce a gain of 1.6384V/V, maximizing
the output voltage swing (Figure 1). The MAX5130/
MAX5131 output amplifier’s offset-adjust pin allows for
a DC shift in the DAC outputs. The full-scale output volt-
age is +4.0955V for the MAX5130 and +2.04775V for
the MAX5131. These DACs are designed with an invert-
ed R-2R ladder network (Figure 2) that produces a
weighted output voltage proportional to the digital input
code.
Both the MAX5130 and MAX5131 use an on-board pre-
cision bandgap reference to generate an output volt-
age of +2.5V (MAX5130) or +1.25V (MAX5131). With a
low temperature coefficient of only 10ppm/°C (max),
the REF pin can source up to 100µA and may become
unstable with capacitive loads exceeding 100pF.
REFADJ can be used for minor adjustments (1%) to the
Figure 1. Simplified Functional Block Diagram
_______________Detailed Description
( ) FOR MAX5131 ONLY
+3V/+5V, 13-Bit, Serial Voltage-Output DACs
RSTVAL
_______________________________________________________________________________________
PDL
CLR
PD
CS
REFERENCE
BANDGAP
CONTROL
Internal Reference
DIN SCLK
SR
MAX5130
MAX5131
1.25V
4k
13
REFADJ
SHIFT REGISTER
16-BIT
V
(1X)
REGISTER
2X
DD
INPUT
REFERENCE
AGND DGND
BUFFER
with Internal Reference
2.5V, (1.25V)
CONTROL
DECODE
Figure 2. Simplified Inverted R-2R DAC Structure
AGND
REF*
SHOWN FOR ALL 1s ON DAC
*INTERNAL 2.5V (MAX5130) AND 1.25V (MAX5131) OR EXTERNAL REFERENCE.
REGISTER
DAC
2R
2R
D0
R
DAC
REF
OUTPUT
LOGIC
GAIN = 1.6384X
2R
D10
0.6384R
R
R
2R
D11
R
DOUT
UPO
OS
OUT
2R
D12
R
0.6384R
OUT
OS
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