REV. A
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a
LOGDAC
CMOS Logarithmic D/A Converter
AD7118*
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
GENERAL DESCRIPTION
The LOGDAC
®
AD7118 is a CMOS multiplying D/A con-
verter which attenuates an analog input signal over the range
0 to –85.5 dB in 1.5 dB steps. The analog output is determined
by a six-bit attenuation code applied to the digital inputs.
Operating frequency range of the device is from dc to several
hundred kHz.
The device is manufactured using an advanced monolithic
silicon gate thin-film on CMOS process and is packaged in a
14-pin dual-in-line package.
ORDERING INFORMATION
Specified
Temperature Accuracy Package
Model Range Range Option
1
AD7118KN 0°C to +70°C 0 to 42 dB N-16
AD7118LN 0°C to +70°C 0 to 48 dB N-16
AD7118BQ –25°C to +85°C 0 to 42 dB Q-16
AD7118CQ –25°C to +85°C 0 to 48 dB Q-16
AD7118TQ
2
–55°C to +125°C 0 to 42 dB Q-16
AD7118UQ
2
–55°C to +125°C 0 to 48 dB Q-16
NOTES
1
N = Plastic DIP; Q = Cerdip.
2
To order MIL-STD-883, Class B processed parts, add /883B to part number.
*Protected by U.S. Patent No. 4521,764.
LOGDAC is a registered trademark of Analog Devices, Inc.
FEATURES
Dynamic Range 85.5 dB
Resolution 1.5 dB
Full 625 V Input Range Multiplying DAC
Full Military Temperature Range –558C to +1258C
Low Distortion
Low Power Consumption
Latch Proof Operation (Schottky Diodes Not Required)
Single 5 V to 15 V Supply
APPLICATIONS
Digitally Controlled AGC Systems
Audio Attenuators
Wide Dynamic Range A/D Converters
Sonar Systems
Function Generators
FUNCTIONAL DIAGRAM
PIN CONFIGURATION