Analog IC Design Techniques for Nanopower Biomedical Signal Processing

MicroelectronicsElectrical Engineering, Mathematics and Computer Scienc

Dynamic translinear nonlinear energy operator

The dynamic translinear principle, in contrast to the conventional, i.e., static, translinear principle, can be used for the realization of frequency dependent transfer functions. Using the dynamic translinear principle we can realize both linear and nonlinear differential equations. This paper presents the dynamic translinear realization of the nonlinear second-order differential equation describing the nonlinear energy operator performing the real time energy detection of analog signals. The expected behavior of the designed nonlinear energy operator is demonstrated by means of simulations. ©2009 IEEE

Ultra-low-power, class-AB, CMOS four-quadrant current multiplier

A class-AB four-quadrant current multiplier constituted by a class-AB current amplifier and a current splitter which can handle input signals in excess of ten times the bias current is presented. The proposed circuit operation is based on the exponential characteristic of BJTs or subthreshold MOSFETs. The multiplier is designed using the latter devices and achieves very low power consumption. Simulation results show that from a 0.65 V supply, the proposed circuit consumes 12.4 nW static power while less than 30 dB total harmonic distortion is achieved for an input modulation index up to 10.Microelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc

A compact, nano-power CMOS action potential detector

Real time action potential (AP) detection is an important requirement for development of fully implantable neuroprosthetic devices. We present an ultra low-power CMOS analog circuit for detection of APs embedded in a noisy signal. The proposed strategy isolates APs by detecting subsequently a positive and a negative spike of each AP. An AP is detected only if the positive spike is detected within a short period of time after the negative spike was detected. The proposed circuit has been designed to be implemented in AMIS 0.35 μ m technology (I3T80) and has been verified in Cadence using RF spectre. The final circuit operates from a 1-V supply and consumes only 1.5 nA. The detector is verified by means of simulations with synthetic neural waveforms and is able to successfully detect APs in noisy signals. ©2009 IEEE

Nanopower sampled data wavelet filter design using Switched Gain Cell technique

In order to realize a nano-power wavelet filter for biomedical applications, this paper applies the Singular Value Decomposition approximation to transform the time domain 1st-derivative of a Gaussian (gauss1) wavelet base into a 5th-order z-domain transfer function. Consequently, to realize the approximated transfer function in CMOS technology employing circuitry that operates from a low supply voltage, a sampled data circuit technique, coined 'Switched Gain Cell, (SGC),' is introduced. Using the SGC technique, standard MOS switches, simple subthreshold (nonlinear) transconductors and their associated parasitic capacitances suffice to constitute the filter, while the scale of the filter can be controlled by the clock frequency. This renders the filter architecture to be simple, modular, and area efficient. Simulation results, using 0.13μm CMOS model parameters, show that the wavelet filter implements the gauss1 wavelet base well, operates from a 1V supply and consumes less than 0.47 μW quiescent power. ©2009 IEEE