Study On The Σ-Δmodulators And ADC

Σ-ΔADCs can achieve high resolution based on oversampling, noise-shaping and decimator filter. It change rate for resolution, proceed high resolution in digital signal process and low resolution at analog field, thereby can attain super performance and integrated system.The principles ofΣ-ΔADCs are discussed firstly. Then the design use the Top-down design method.The architecture and design methods ofΣ-ΔADCs are studied. Based on it, proposal the overall design, give the system construct and specific design index. Behavior emulation is based on Simulink, then demonstrate the emulation outcome according with the anticipate result.The design ofΣ-Δmodulators firstly is the system level emulation, then design in detail of each modular circuit, which include bandgap voltage source, operational amplifier, comparator and so on. Using the Hspice to emulate the modular circuit. At last, accomplish the layout design. This part was accomplished on 0.6μm Bicmos process with Chartered Semiconductor Manufacturing Ltd.The design of decimator filter is important. The comb filter and halfband filter are selected, first of all definite the system, according to the structure I compile the Verilog code, in Synplify complete the RTL and GATE circuit, then realize the base unite and route, map the circuit to layout, complete the whole layout.Test result is based on IMS GEMNI test equipment. The main content of chip testing is included that producing the test board, compiling the test pattern and using the software of IMS-tools and Labview.