Browsing by Author "LU, PH"

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DESIGN TECHNIQUES FOR HIGH-FREQUENCY CMOS SWITCHED-CAPACITOR FILTERS USING NON-OP-AMP-BASED UNITY-GAIN AMPLIFIERS
(1991-10-01)
WU, CY
;
LU, PH
;
TSAI, MK
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A fully differential non-op-amp-based unity-gain amplifier (UGA) is proposed, whose 3-dB frequency can be as high as 250 MHz in 3.5-mu-m p-well CMOS technology. Suitable predistortions can be introduced under the aid of CAD tools to reduce the parasitic effects. Experimental results have successfully proven the capability of the proposed structures in the realization of high-frequency switched-capacitor filters over the megahertz range. Filter accuracy can be further enhanced by using the tunable-gain UGA, which enables tuning on filter parameters.
THE DESIGN OF FULLY DIFFERENTIAL CMOS OPERATIONAL-AMPLIFIERS WITHOUT EXTRA COMMON-MODE FEEDBACK-CIRCUITS
(1993-09-01)
LU, PH
;
WU, CY
;
TSAI, MK
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new fully differential CMOS operational amplifier (op amp) without extra common-mode feedback (CMFB) circuit is proposed and analyzed. In this op amp, simple inversely connected current-mirror pairs are used as active loads. From the theoretical analysis, it is shown that the common-mode signal can be efficiently suppressed by the reduced effective common-mode resistance of the active load. The proposed op amp with 2 pF capacitance loadings has an open-loop unity-gain bandwidth of 63 MHz, a phase margin 47-degrees, and a dc gain of 67 dB in 3.5 mum p-well CMOS technology. The common-mode gain at a single output node can be as low as -38 dB without extra CMFB circuit. Experimental results have successfully confirmed the capability of the efficient common-mode rejection.
VHF UHF HIGH-Q BANDPASS TUNABLE FILTERS DESIGN USING CMOS INVERTER-BASED TRANSRESISTANCE AMPLIFIERS
(1994)
LU, PH
;
WU, CY
;
TSAI, MK
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics