Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2

decimation filter Related Abstracts

2 Design of Decimation Filter Using Cascade Structure for Sigma Delta ADC

Authors: Metuku Shyamsunder, Misbahuddin Mahammad, P. Chandra Sekhar


The oversampled output of a sigma-delta modulator is decimated to Nyquist sampling rate by decimation filters. The decimation filters work twofold; they decimate the sampling rate by a factor of OSR (oversampling rate) and they remove the out band quantization noise resulting in an increase in resolution. The speed, area and power consumption of oversampled converter are governed largely by decimation filters in sigma-delta A/D converters. The scope of the work is to design a decimation filter for sigma-delta ADC and simulation using MATLAB. The decimation filter structure is based on cascaded-integrated comb (CIC) filter. A second decimation filter is using CIC for large rate change and cascaded FIR filters, for small rate changes, to improve the frequency response. The proposed structure is even more hardware efficient.

Keywords: sigma delta modulator, CIC filter, decimation filter, compensation filter, noise shaping

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1 An Efficient Digital Baseband ASIC for Wireless Biomedical Signals Monitoring

Authors: Jia Hao Cheong, Xin Liu, Kah-Hyong Chang, Saisundar Sankaranarayanan, Dexing Pang, Hongzhao Zheng


A digital baseband Application-Specific Integrated Circuit (ASIC) is developed for a microchip transponder to transmit signals and temperature levels from biomedical monitoring devices. The transmission protocol is adapted from the ISO/IEC 11784/85 standard. The module has a decimation filter that employs only a single adder-subtractor in its datapath. The filtered output is coded with cyclic redundancy check and transmitted through backscattering Load Shift Keying (LSK) modulation to a reader. Fabricated using the 0.18-μm CMOS technology, the module occupies 0.116 mm² in chip area (digital baseband: 0.060 mm², decimation filter: 0.056 mm²), and consumes a total of less than 0.9 μW of power (digital baseband: 0.75 μW, decimation filter: 0.14 μW).

Keywords: Temperature Sensor, Biomedical Sensor, decimation filter, radio frequency integrated circuit (RFIC) baseband

Procedia PDF Downloads 243