Modeling and Analysis of On-Chip Power Noise Induced by an On-Chip Linear Voltage Regulator Module with a High-Speed Output Buffer


In this paper, analytical models of on-chip power noise induced by an on-chip linear voltage regulator module (VRM) circuit with a high-speed output buffer are proposed. Based on the piecewise linear approximated MOSFET I-V curve model, closed-form equations for the on-chip power noise induced by an on-chip low-dropout regulator are derived. The accuracy of the proposed analytical model is validated by SPICE simulation with a 110-nm CMOS technology library. Based on the proposed analytical models, the impacts of VRM design parameters on VRM output noise induced by load current and external noises are analyzed. Because self-impedance at the VRM output and external noise transfer functions share a common resonant frequency, the on-chip power noise is minimized by avoiding the resonant frequency from peak frequencies of noise source spectrums. The larger on-chip decoupling capacitance at load reduces, the overall on-chip VRM output noise. While the larger pass transistor size reduces the on-chip VRM output noise induced by the reference voltage fluctuation, it increases the noise generated by off-chip power fluctuation. The reference voltage node needs to be carefully designed, as opposed to an off-chip power distribution network, due to its dominant impact on the on-chip VRM output noise. The analysis results based on the proposed model provide an in-depth understanding of and useful design guidance for on-chip power noise induced by the on-chip linear VRM with a high-speed output buffer.


Electrical and Computer Engineering


This work was supported by the National Science Foundation under Grant IIP-1440110.

Keywords and Phrases

Capacitance; Electric current regulators; Electric load management; Integrated circuit design; Mathematical models; Natural frequencies; Piecewise linear techniques; SPICE; System-on-chip; Transistors; Voltage regulators; Integrated circuit modeling; Linear voltage regulators; Load modeling; Low-dropout regulators; On-chip power distribution; On-chip power noise; Output Buffer; Analytical models; High-speed output buffer; On-chip linear voltage regulator module (VRM); On-chip low-dropout (LDO) regulator; On-chip power distribution network (PDN); Regulators

International Standard Serial Number (ISSN)

0018-9375; 1558-187X

Document Type

Article - Journal

Document Version


File Type





© 2019 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jun 2020