A Dual-Slope Integration Based Analog-to-Digital Convertor

Abstract

Problem statement: With the advent of the advanced technology and the need for more advanced equipment, the current progress and development of electronic instruments stimulate more interest and efforts for more innovative ideas and better designs. Many real world physical values, such as sounds, temperature, pressure and humidity, can be measured as analog or continuous signals. However, to process these signals by computers or digital equipments, we need first to convert these analog signals into digital or discreet signals. Approach: There are many types of Analog-to-Digital Converters (ADCs) which can be classified according to the concept on which they were designed. For example, there are charge-coupled A/D converter, digital-ramp A/D converter, successive approximation A/D converter, voltage-to-frequency A/D converter, Delta-Sigma A/D converter, Flash A/D converter and some of these converters require the use of Digital-to-Analog Converters (DACs) and/or analog comparators and some logic modules. In some other cases, many analog comparators are needed to perform the conversion. We are trying to use a different approach that reduce the design complexity and improve the measurement quality by using the double-slope integration concept. Result: The new design does not require the use of a DAC module, nor does it need to use many analog comparators to do the conversion. Conclusion: The advantage of the new design would contribute to the simplicity of the design, enhance its reliability and guarantee the linearity of the conversion process that leads into better quality instruments.