Analog Devices AN-292 Application Note Interfacing the AD7572A to High-Speed DSP Processors

About this manual

The document describes the AD7572A, a 12-bit CMOS analog-to-digital converter, and addresses the challenge of interfacing it with high-performance microprocessors that have faster data access times than the ADC can support. It details the use of wait states to extend bus access time and reduce noise issues caused by high-speed microprocessor activity.

Furthermore, the note provides specific interface circuits for the TMS32020 and ADSP-2100 processors. It discusses using external timers, such as the 8254 or a 74393 counter, to ensure equal sampling intervals and allow the processor to operate at maximum speed while the ADC performs conversions.

What's inside

• The AD7572A
• Interfacing to High-Speed DSP Processors
• The Use of Wait States
• Microprocessor Noise
• Equal Sampling Intervals
• AD7572A/TMS32020 Interface
• AD7572A/ADSP-2100 Interface
• Timing Diagrams

Specifications

Frequently asked questions

How can microprocessor noise be eliminated during ADC conversion?

Noise can be eliminated by using wait states for the duration of the ADC conversion time or by using three-state buffers to isolate the ADC data bus.

What is the advantage of using an external timer for conversion control?

Using an external timer allows the processor to operate at maximum speed while the AD7572A performs conversions at constant sampling intervals.