Current mode analog to digital converters based on current multiplication and division technique

This thesis reports development and simulation of two analog-to-digital (AD) converters for low-power and small area applications, such as implantable telemetric biomedical recording applications. In development of these analog-to-digital (AD) converters current mode signal processing is chosen. Current mode signal processing has some advantages over voltage mode signal processing in low voltage and low power applications because of not requiring high precision resistors or capacitors. And one reason to be chosen current mode signal processing is many signal sources are current-type, such as temperature sensors, photo sensors and many others in biomedical. Processing the signal in current will not only avoid the use of a current to voltage converter but also cut down the components costs. Current mode analog-to-digital converters use current mirrors to perform the required conversion. Therefore, the performances of the analog-to-digital converters are limited by the performance of the current mirrors. In the development of these ADCs, different types of current mirrors are used to improve. These current mirrors used have better output impedance than current mirror used in the previous designs. To decrease the complexity and power consumption clock-less architecture is chosen. By increasing the accuracy one more level is added to previous design. Key words: Analog to digital converter, current mode approach, current mirror