a FEATURES Complete 8-Bit A/D Converter with Reference, Clock and Comparator 30 s Maximum Conversion Time Full 8- or 16-Bit Microprocessor Bus Interface Unipolar and Bipolar Inputs No Missing Codes Over Temperature Operates on +5 V and –12 V to –15 V Supplies MIL-STD-883 Compliant Version Available
8-Bit A/D Converter AD673* FUNCTIONAL BLOCK DIAGRAM VCC
CONVERT MSB DB7
8-BIT CURRENT OUTPUT DAC
DB5 DB4 DB3
BIPOLAR OFFSET CONTROL
DB1 DB0 LSB DATA ENABLE
The AD673 is a complete 8-bit successive approximation analog-to-digital converter consisting of a DAC, voltage reference, clock, comparator, successive approximation register (SAR) and 3-state output buffers—all fabricated on a single chip. No external components are required to perform a full accuracy 8-bit conversion in 20 µs. The AD673 incorporates advanced integrated circuit design and processing technologies. The successive approximation function is implemented with I2L (integrated injection logic). Laser trimming of the high stability SiCr thin-film resistor ladder network insures high accuracy, which is maintained with a temperature compensated sub-surface Zener reference. Operating on supplies of +5 V and –12 V to –15 V, the AD673 will accept analog inputs of 0 V to +10 V or –5 V to +5 V. The trailing edge of a positive pulse on the CONVERT line initiates the 20 µs conversion cycle. DATA READY indicates completion of the conversion. The AD673 is available in two versions. The AD673J as specified over the 0°C to +70°C temperature range and the AD673S guarantees ± 1/2 LSB relative accuracy and no missing codes from –55°C to +125°C.
BURIED ZENER REF DATA READY
1. The AD673 is a complete 8-bit A/D converter. No external components are required to perform a conversion. 2. The AD673 interfaces to many popular microprocessors without external buffers or peripheral interface adapters. 3. The device offers true 8-bit accuracy and exhibits no missing codes over its entire operating temperature range. 4. The AD673 adapts to either unipolar (0 V to +10 V) or bipolar (–5 V to +5 V) analog inputs by simply grounding or opening a single pin. 5. Performance is guaranteed with +5 V and –12 V or –15 V supplies. 6. The AD673 is available in a version compliant with MILSTD-883. Refer to the Analog Devices Military Products Databook or current AD673/883B data sheet for detailed specifications.
Two package configurations are offered. All versions are also offered in a 20-pin hermetically sealed ceramic DIP. The AD673J is also available in a 20-pin plastic DIP. *Protected by U.S. Patent Nos. 3,940,760; 4,213,806; 4,136,349; 4,400,689; and 4,400,690.
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