Chutham Sawigun

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—Two prior-art transconductance amplifier-based rail-to-rail class-AB analog buffers are examined. Their analysis reveals that the output current drive capability for large input voltages is restricted. To mitigate this drawback, a relatively simple slew-rate enhancement scheme is proposed. The new scheme allows the buffer's speed to be increased by over(More)
— A nano-power 4 th-order band-pass filter operating from a 0.5 V supply voltage with an adjustable center frequency, ranging from 250 Hz to 4 kHz (4 octaves), is presented. The filter is constituted from cascadable 2 nd-order circuit cells that are realized by a network of three transistors and two capacitors comprising only one branch of bias current. As(More)
—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 1 st-derivative of a Gaussian (gauss1) wavelet base into a 5 th-order z-domain transfer function. Consequently, to realize the approximated transfer function in CMOS technology employing(More)
— According to recent physiological experiments, the envelope and phase of speech signals are required to enhance the perceptive capability of a cochlear implant processor. In this paper, the design of an analog complex gammatone filter is introduced in order to extract both envelope and phase information of the incoming speech signals as well as to emulate(More)
—This paper proposes the design of a current-mode sample and hold circuit using subthreshold MOSFETs. The proposed circuit combines negative feedback and the compressive characteristic of a class-AB weak inversion transconductor to achieve low switching error, high signal-to-noise ratio and high dynamic range from a low supply voltage and very low current(More)
A class-AB switched current memory cell is proposed. The circuit decomposes the input signal into two components by a low-voltage class-AB current splitter and subsequently processes the individual signals by two low switching error class-A memory cells. As a consequence , the output current obtained by recombination of the separated signals can be higher(More)
— An ultra low-power, high linearity, wide swing, current sample-and-hold circuit is presented. The proposed circuit employs negative feedback, provides very low switching error and allows for class-AB operation. Sub-threshold CMOS devices are employed to realize all circuit building blocks which leads to ultra low power consumption and large dynamic range.(More)