Two 12-Bit/14-Bit DACs with Output Amplifiers
AD7242: 12-Bit Resolution
AD7244: 14-Bit Resolution
On-Chip Voltage Reference
Fast Settling Time
AD7242: 3 s to ؎1/2 LSB
AD7244: 4 s to ؎1/2 LSB
High Speed Serial Interface
Operates from ؎5 V Supplies
Specified Over –40؇C to +85؇C in Plastic Packages
Low Power – 130 mW typ
LC2MOS Dual, Complete,
12-Bit/14-Bit Serial DACs
FUNCTIONAL BLOCK DIAGRAM
The AD7242/AD7244 is a fast, complete, dual 12-bit/14-bit
voltage output D/A converter. It consists of a 12-bit/14-bit
DAC, 3 V buried Zener reference, DAC output amplifiers and
high speed serial interface logic.
Interfacing to both DACs is serial, minimizing pin count and
allowing a small package size. Standard control signals allow
interfacing to most DSP processors and microcontrollers.
Asynchronous control of DAC updating for both DACs is made
possible with a separate LDAC input for each DAC.
The AD7242/AD7244 operates from ± 5 V power supplies,
providing an analog output range of ± 3 V. A REF OUT/REF
IN function allows the DACs to be driven from the on-chip 3 V
reference or from an external reference source.
The AD7242/AD7244 is fabricated in Linear Compatible
CMOS (LC2MOS), an advanced mixed technology process that
combines precision bipolar circuits with low power CMOS
logic. Both parts are available in a 24-pin, 0.3-inch wide, plastic
or hermetic dual-in-line package (DIP) and in a 28-pin, plastic
small outline (SOIC) package. The AD7242 and AD7244 are
available in the same pinout to allow easy upgrade from 12-bit
to 14-bit performance.
1. Complete, Dual 12-Bit/14-Bit DACs
The AD7242/AD7244 provides the complete function for
generating voltages to 12-bit/14-bit resolution. The part
features an on-chip reference, output buffer amplifiers and
two 12-bit/14-bit D/A converters.
2. High Speed Serial Interface
The AD7242/AD7244 provides a high speed, easy-to-use,
serial interface allowing direct interfacing to DSP processors
and microcontrollers. A separate serial port is provided for
3. Small Package Size
The AD7242/AD7244 is available in a 24-pin DIP and a 28-
pin SOIC package offering considerable space saving over
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© Analog Devices, Inc., 1996