DAC1208 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – 12-Bit, uP Compatible, Double-Buffered D to A Converters

February 1995
MICRO-DAC^TM DAC1208 DAC1209 DAC1210 DAC1230
DAC1231 DAC1232 12-Bit mP Compatible
Double-Buffered D to A Converters
General Description
The DAC1208 and the DAC1230 series are 12-bit multiply-
ing D to A converters designed to interface directly with a
wide variety of microprocessors (8080 8048 8085 Z-80
etc ) Double buffering input registers and associated con-
trol lines allow these DACs to appear as a two-byte ‘‘stack’’
in the system’s memory or I O space with no additional in-
terfacing logic required
The DAC1208 series provides all 12 input lines to allow sin-
gle buffering for maximum throughput when used with 16-bit
processors These input lines can also be externally config-
ured to permit an 8-bit data interface The DAC1230 series
can be used with an 8-bit data bus directly as it internally
formulates the 12-bit DAC data from its 8 input lines All of
these DACs accept left-justified data from the processor
The analog section is a precision silicon-chromium (Si-Cr)
R-2R ladder network and twelve CMOS current switches
An inverted R-2R ladder structure is used with the binary
weighted currents switched between the I_OUT1 and I_OUT2
maintaining a constant current in each ladder leg indepen-
dent of the switch state Special circuitry provides TTL logic
input voltage level compatibility
The DAC1208 series and DAC1230 series are the 12-bit
members of a family of microprocessor compatible DACs
(MICRO-DACs^TM) For applications requiring other resolu-
tions the DAC1000 series for 10-bit and DAC0830 series
for 8-bit are available alternatives
Features
Y _{Linearity specified with zero and full-scale adjust only}
Y _{Direct interface to all popular microprocessors}
Y _{Double-buffered single-buffered or flow through digital}
data inputs
Y _{Logic inputs which meet TTL voltage level specs (1 4V}
logic threshold)
Y _{Works with} g_{10V reference full 4-quadrant}
multiplication
Y _{Operates stand-alone (without mP) if desired}
Y _{All parts guaranteed 12-bit monotonic}
Y _{DAC1230 series is pin compatible with the DAC0830}
series 8-bit MICRO-DACs
Key Specifications
Y _{Current Settling Time}
Y _Resolution
Y _{Linearity (Guaranteed}
over temperature)
Y _{Gain Tempco}
Y _{Low Power Dissipation}
Y _{Single Power Supply}
1 ms
12 Bits
10 11 or 12 Bits of FS
1 3 ppm C
20 mW
5 V_DC to 15 V_DC
Typical Application
TRI-STATE is a registered trademark of National Semiconductor Corp
MICRO-DACTM is a trademark of National Semiconductor Corp
C1995 National Semiconductor Corporation TL H 5690
TL H 5690 – 1
RRD-B30M115 Printed in U S A