Rainbow Electronics MAX545 - Manual (Page 7)

MAX544/MAX545
+5V, Serial-Input, Voltage-Output, 14-Bit DACs
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Detailed Description
The MAX544/MAX545 voltage-output, 14-bit digital-to-
analog converters (DACs) offer full 14-bit performance
with less than 0.5LSB integral linearity error and less
than 0.9LSB differential linearity error, thus ensuring
monotonic performance. Serial-data transfer minimizes
the number of package pins required.
The MAX544/MAX545 are composed of two matched
DAC sections, with an inverted R-2R DAC forming the
LSBs and the four MSBs derived from 15 identically
matched resistors. This architecture allows the lowest
glitch energy to be transferred to the DAC output on
major-carry transitions. It also lowers the DAC output
impedance by a factor of eight compared to a standard
R-2R ladder, allowing unbuffered operation in medium-
load applications.
The MAX545 provides matched bipolar offset resistors,
which connect to an external op amp for bipolar output
swings (Figure 2b). For optimum performance, the
MAX545 also provides a set of Kelvin connections to
the voltage-reference and analog-ground inputs.
MAX545
MAX400
AGNDF DGND
(GND)
V DD REFF REFS
R INV
R FB
RFB
INV
OUT
LDAC
SCLK
DIN
CS
AGNDS
0.1 µF
+5V
EXTERNAL OP AMP
MC68XXXX
PCS0
MOSI
SCLK
IC1
BIPOLAR
OUT
+5V
-5V
0.1 µF
+2.5V
10 µF
Figure 2b. Typical Operating Circuit—Bipolar Output
MAX544/MAX545
MAX495
DGND
( ) ARE FOR MAX545 ONLY
(GND)
V DD (REFS) REF (REFF)
OUT
SCLK
DIN
CS
AGND_
0.1 µF
0.1 µF
+5V +2.5V
EXTERNAL OP AMP
MC68XXXX
PCS0
MOSI
SCLK
UNIPOLAR
OUT
( LDAC )
10 µF
Figure 2a. Typical Operating Circuit—Unipolar Output