2
LC MOS
Octal 8-Bit DAC
a
AD7228A
FEATURES
FUNCTIO NAL BLO CK D IAGRAM
Eight 8-Bit DACs w ith Output Am plifiers
Operates w ith Single +5 V, +12 V or +15 V
or Dual Supplies
P Com patible (95 ns WR Pulse)
No User Trim s Required
Skinny 24-Pin DlPs, SOIC, and 28-Term inal Surface
Mount Packages
GENERAL D ESCRIP TIO N
T he AD7228A contains eight 8-bit voltage-mode digital-to-
analog converters, with output buffer amplifiers and interface
logic on a single monolithic chip. No external trims are required
to achieve full specified performance for the part.
P RO D UCT H IGH LIGH TS
1. Eight DACs and Amplifiers in Small Package
T he single-chip design of eight 8-bit DACs and amplifiers al-
lows a dramatic reduction in board space requirements and
offers increased reliability in systems using multiple convert-
ers. Its pinout is aimed at optimizing board layout with all
analog inputs and outputs at one side of the package and all
digital inputs at the other.
Separate on-chip latches are provided for each of the eight D/A
converters. Data is transferred into the data latches through a
common 8-bit T T L/CMOS (5 V) compatible input port. Ad-
dress inputs A0, A1 and A2 determine which latch is loaded
when WR goes low. T he control logic is speed compatible with
most 8-bit microprocessors.
2. Single or Dual Supply Operation
Specified performance is guaranteed for input reference voltages
from +2 to +10 V when using dual supplies. T he part is also
specified for single supply +15 V operation using a reference of
+10 V and single supply +5 V operation using a reference of
+1.23 V. Each output buffer amplifier is capable of developing
+10 V across a 2 kΩ load.
T he voltage-mode configuration of the DACs allows single
supply operation of the AD7228A. T he part can also be oper-
ated with dual supplies giving enhanced performance for
some parameters.
3. Microprocessor Compatibility
T he AD7228A has a common 8-bit data bus with individual
DAC latches, providing a versatile control architecture for
simple interface to microprocessors. All latch enable signals
are level triggered and speed compatible with most high per-
formance 8-bit microprocessors.
T he AD7228A is fabricated on an all ion-implanted, high-
speed, Linear Compatible CMOS (LC2MOS) process which has
been specifically developed to integrate high-speed digital logic
circuits and precision analog circuits on the same chip.
REV. A
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norw ood, MA 02062-9106, U.S.A.
Tel: 617/ 329-4700
Fax: 617/ 326-8703