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Capacitance-to-Digital Converter Simplifies Instrumentation and Sensor Design

Analog Devices, Inc. announced the high-precision, fully integrated converters that address the complex and difficult signal processing challenges of direct capacitance-to-digital. Combining advanced signal processing techniques with high levels of integration, ADI’s capacitance-to-digital converter (CDC) attains a level of precision previously only possible with conventional analog voltage-to-digital converters aided by a significant number of discrete components. ADI’s devices provide designers significant advantages over existing discrete solutions for capacitance- and impedance-sensing applications that have historically lacked precision and proven difficult and expensive to design. The devices are ideal for a wide range of high-performance instrumentation and sensing applications, from blood pressure monitors and glucose analyzers to position sensors for automobiles and industrial corrosion analysis systems.

Single-chip, high precision CDC – the AD7745/6/7 CDC integrates all stages of capacitance-to-digital conversion on one chip reducing costs associated with traditional multi-chip solutions by 65 percent. With 24-bit resolution, the AD7745 is the industry’s highest-precision solution for interfacing with capacitive sensors. Ideal for industrial and medical instrumentation and automotive sensing applications. The AD7745 and AD7746 are configured for two-electrode capacitance sensors, while the AD7747 is for one-electrode devices. Specifications include an operating range from 2.7 to 5.25 V, an accuracy of 2 x 10^-15 F, a speed of 5 to 90 Hz, and a power consumption of 1 mA max.

Contact:

Sue Martenson,

Analog Devices, Inc., Wilmington, MA

781-937-1989, 781-937-1026

Technical Support 800-262-5643
Fax: 781-461-4482
E-mail: Sue.martenson@analog.com