The AD7821 is a high-speed, 8-bit, sampling, analog-to-digital converter that offers improved performance over the popular AD7820. It offers a conversion time of 660 ns (vs. 1.36 µs for the AD7820) and 100 kHz signal bandwidth (vs. 6.4 kHz). The sampling instant is better defined and occurs on the falling edge of WR of RD. The provision for a VSS pin (Pin 19) allows the part to operate from ±5 V supplies and to digitize bipolar input signals. Alternatively, for unipolar inputs, the VSS pin can be grounded and the AD7821 will operate from a single +5 V supply, like the AD7820.
The AD7821 has a built-in track-and-hold function capable of digitizing full-scale signals up to 100 kHz max. It also uses a half-flash conversion technique that eliminates the need to generate a CLK signal for the ADC.
The AD7821 is designed with standard microprocessor control signals (CS, RD, WR, RDY, INT) and latched, three-state data outputs capable of interfacing to high-speed data buses. An overflow output (OFL) is also provided for cascading devices to achieve higher resolution.
The AD7821 is fabricated in Linear-Compatible CMOS (LC2MOS), an advanced, mixed technology process combining precision bipolar circuits with low-power CMOS logic. The part features a low power dissipation of 50 mW.
|Title||Content Type||File Type|
|AD7821: High Speed, µP-Compatible, CMOS, 8-Bit Sampling ADC Data Sheet (Rev B, 11/2002) (pdf, 811 kB)||Data Sheets|
|AD7821: Military Data Sheet (Rev A, 07/2002) (pdf)||Data Sheets|
|AN-299: Simple Circuit Provides Ratiometric Reference Levels for AD782X Family of Half-Flash ADCs (pdf, 170 kB)||Application Notes|
ADI Warns Against Misuse of COTS Integrated Circuits
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Invites Customer Participation in Creative Mil/Aero System Solutions
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Space Qualified Parts List
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This document lists 67 (240+) space level products that are available from Analog Devices. Many of the products listed are state-of-the-art data conversion and signal processing products that were previously only available as commercial or military Class B products. Through our Space Products Group and MIL-PRF-38535 certified Level V (Class S) facility, we are pleased to offer these products to the space marketplace.
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|Glossary of EE Terms||Glossary||HTML|
Symbols and Footprints— Analog Devices offers Symbols & Footprints which are compatible with a large set of today’s CAD systems for broader and easier support.
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