a
FEATURES
Eight 8-Bit DACs with Output Amplifiers
Operates with Single +5 V, +12 V or +15 V
or Dual Supplies
P Compatible (95 ns
WR
Pulse)
No User Trims Required
Skinny 24-Pin DlPs, SOIC, and 28-Terminal Surface
Mount Packages
LC MOS
Octal 8-Bit DAC
AD7228A
FUNCTIONAL BLOCK DIAGRAM
2
GENERAL DESCRIPTION
The 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.
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 TTL/CMOS (5 V) compatible input port. Ad-
dress inputs A0, A1 and A2 determine which latch is loaded
when
WR
goes low. The control logic is speed compatible with
most 8-bit microprocessors.
Specified performance is guaranteed for input reference voltages
from +2 to +10 V when using dual supplies. The 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.
The AD7228A is fabricated on an all ion-implanted, high-
speed, Linear Compatible CMOS (LC
2
MOS) process which has
been specifically developed to integrate high-speed digital logic
circuits and precision analog circuits on the same chip.
PRODUCT HIGHLIGHTS
1. Eight DACs and Amplifiers in Small Package
The 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.
2. Single or Dual Supply Operation
The voltage-mode configuration of the DACs allows single
supply operation of the AD7228A. The part can also be oper-
ated with dual supplies giving enhanced performance for
some parameters.
3. Microprocessor Compatibility
The 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.
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
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