Analog Digital Conversion Handbook

This handbook by Digital Equipment Corporation provides a comprehensive guide to analog-digital (A-D) and digital-analog (D-A) conversion, suitable for both beginners and experts. It details various conversion techniques, performance characteristics, and practical implementation using DEC's modular circuits.

The document begins by outlining the fundamental elements of D-A conversion, primarily using resistive divider networks, and introduces several A-D conversion methods: simultaneous, counter, continuous, and successive approximation, along with sample-and-hold and multiplexing concepts.

It then delves into the measures of converter performance, explaining accuracy, various error sources (digital quantization, analog offset, gain, linearity, differential linearity), error distribution, monotonicity, and crucial speed metrics like settling time and aperture time for both D-A and A-D systems.

Specialized A-D conversion techniques are explored, including section counters, ramp methods, continuous converters with added comparators, successive approximation with redundancy, subranging, sequential approximation, and quantizing encoders, which are often used for higher speed or particular applications.

The handbook provides detailed guidance on typical converter logic, recommending specific DEC modules for constructing D-A and different A-D converter types (simultaneous, counter, continuous, successive approximation) based on desired word length and speed. It also addresses practical considerations like transient management and module selection.

Subsequent chapters cover basic circuit components such as divider networks, level amplifiers, reference supplies, comparators, and multiplexer switches. It provides practical instructions for interconnection and calibration, including grounding, shielding, and adjusting offset, gain, and speed. Finally, methods for testing A-D converters are detailed, covering monotonicity, accuracy, noise, and transient response. Appendices include information on signed numbers, bipolar voltages, and digital standards. The guide emphasizes the advantages of using modular components for flexibility, cost-effectiveness, and in-house calibration.