High-level synthesis of switched-capacitor, switched-current and continuous-time /spl Sigma//spl Delta/ modulators using SIMULINK-based time-domain behavioral models

This paper presents a high-level synthesis tool for /spl Sigma//spl Delta/ modulators (/spl Sigma//spl Delta/Ms) that combines an accurate SIMULINK-based time-domain behavioral simulator with a statistical optimization core. Three different circuit techniques for the modulator implementation are considered: switched-capacitor, switched-current and continuous-time. The behavioral models of these circuits, that take into account the most critical limiting factors, have been incorporated into the SIMULINK environment by using S-function blocks, which drastically increase the computational efficiency. The precision of these models has been validated by electrical simulations using HSPICE and experimental measurements from several silicon prototypes. The combination of high accuracy, short CPU time and interoperability of different circuit models together with the efficiency of the optimization engine makes the proposed tool an advantageous alternative for /spl Sigma//spl Delta/M synthesis. The implementation on the well-known MATLAB/SIMULINK platform brings numerous advantages in terms of data manipulation, processing capabilities, flexibility and simulation with other electronic subsystems. Moreover, this is the first tool dealing with the synthesis of /spl Sigma//spl Delta/Ms using both discrete-time and continuous-time circuit techniques.     

A 1.2?V 10-bit 60-MS/s 23?mW CMOS pipeline ADC with 0.67?pJ/conversion-step and on-chip reference voltages generator

A 1.2?V 10-bit 60?MS/s pipeline Analog-to-Digital Converter (ADC), fabricated in a 130?nm CMOS technology, is presented. The prototype is composed by five 3-bit pipeline stages and a Sample and Hold (S&H) circuit at the front. Two-stage Miller-compensated Operational Transconductance Amplifiers (OTAs), offset-compensated comparators and bootstrapping sampling switches have been used due to the low voltage supply requirements. Special attention has been paid to the reduction of the power consumption using a thorough design methodology. The converter only consumes 23?mW including on-chip reference voltages and bias current generators. The differential and integral nonlinearity of the ADC are below 0.60 and 0.61 LSBs, respectively. The pipeline converter achieves an effective resolution above 9 bits along the Nyquist bandwidth, and obtains 0.67?pJ energy consumption per conversion, making it one of the most energy-efficient 10-bit video-rate pipeline ADC reported to date.