Faculty of electronics and computer science

Prototyping of third-order sigma-delta analog to digital converters (Sigma Delta ADCs) has been presented in the paper. The method is based on implementation of field programmable analog arrays (FPAA) to configure and reconfigure proposed circuits. Three third-order Sigma Delta ADC structures have been considered. The circuit characteristics have been measured and then
the structure of the converters have been reconfigured to satisfy input specifications.

A rapid prototyping method for designing mixed signal systems has been presented in the paper. The method is based on implementation of the field programmable analog array (FPAA) to configure and reconfigure mixed signal systems. A serial algorithmic analog digital converter has been used as an example. Three converter architectures have been selected and implemented FPAA device. To verify and illustrate converters operation and prototyping capabilities, implemented converters have been excited by a sinusoidal signal. Analog sinusoidal excitations, digital responses and sinusoidal waveforms after reconstruction are presented.

A low power, low voltage current mode 9 bit pipelined a/d converter and 8 bit self-calibrated d/a converter to interface a DSP system are presented in the paper. The a/d converter is built of 1.5 bit stages with digital error correction logic. The d/a converter is composed of 3 LSBs fine and 5 MSBs coarse current mode converters. The a/d and d/a converters were designed in 0.35 μm technology, then fabricated to verify the proposed concept. The performances of both converters are compared to the performances of known converter structures. The main advantages of the proposed converters are low power consumption and small chip area.

This paper, presents a novel low power current mode 9 bit pipelined a/d converter. The a/d converter structure is composed of three 2.5 bit stages and one 3 bit stage operating in current mode and a final comparator which converts the analog current signal into a digital voltage signal. All the building blocks of the converter were designed in CMOS AMS 0.35 um technology, simulated, and then a prototype converter was manufactured and measured to verify the proposed concept. The performances of the converter are compared to performances of known voltage-mode switched-capacitance and current-mode switched-current converter structures. Low power consumption and small chip area are the advantages of the proposed converter.

A rapid prototyping method for designing mixed signal systems has been presented in the paper. The method is based on implementation of field programmable analog arrays to configure and reconfigure mixed signal systems. A serial algorithmic analog digital converter has been used as an example. The circuit characteristics have been measured and then structure of the converter has been reconfigured to satisfy input specifications.