Browsing by Author "Chao, Hao-Ming"

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An Active Guarding Circuit Design for Wideband Substrate Noise Suppression
(2008-11-01)
Chao, Hao-Ming
;
Wuen, Wen-Shen
;
Wen, Kuei-Ann
;
電子工程學系及電子研究所
;
友訊交大聯合研發中心
In this paper, an active guarding circuit is presented for wideband substrate noise suppression. A feed-forward compensation mechanism is proposed to extend the noise suppression bandwidth and to adjust the amplitude of phase-inversed noise cancellation current by introducing a zero and an amplitude controller. A noise decoupling mechanism is developed to provide a decoupling path and to sense the noise level for generating noise cancellation current. With substrate characterization, parameters of substrate network impedance, decoupling factor, and amplitude of noise cancellation current can be either obtained or determined. The active guarding circuit is implemented in a 90-nm CMOS process based on substrate characterization. The measured substrate noise suppression is better than -9 dB from dc to 250 MHz. The -3-dB suppression bandwidth is effectively extended to 1.2 GHz. The power consumption and circuit area are 2.5 mW and 20 mu m x 41 mu m, respectively.
An active guarding circuit for giga-hertz substrate noise suppression
(2007)
Chao, Hao-Ming
;
Wang, Chien-Lung
;
Wuen, Wen-Shen
;
Wen, Kuei-Ann
;
電子工程學系及電子研究所
This paper presents an active guarding circuit employing noise decoupling and inversion feedback for substrate noise suppression in high frequency up to GHz. Proposed inversion feedback circuit can efficiently suppress substrate noise up to GHz range by introducing a zero within an amplitude controller. The noise decoupling circuit not only provides a decoupling path, but also senses the noise level for the amplitude controller to perform noise cancellation. By applying the proposed active guarding circuit, the noise suppression of passive guard ring can be improved more than 14dB in the frequency range from DC to 1GHz and 7.2dB up to 5GHz. For 1dB degradation of noise suppression performance, the input noise level can be up to 90mV at 1MHz and 86mV at 1GHz, respectively.