A Precise Sub-milliohm DCR Current Sensing Scheme for Area-Efficient Multiphase Peak Current Mode Controller

This paper proposes a low direct current resistance (DCR) current sensing scheme for multiphase peak current mode controller. A second order RC sensing network amplifies the high frequency sensing signal and also extracts the low frequency signal. The sensing error of traditional DCR current sensing...

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Bibliographic Details
Main Authors: Yan, Yingyi, Gu, Eric
Format: Conference Proceeding
Language:English
Subjects:
current balancing
current mode control
DCR current sensing
multiphase
Pulse width modulation
Real-time systems
Resistance
Sensors
signal-to-noise ratio
Silicon
System-on-chip
Time-frequency analysis
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Summary:This paper proposes a low direct current resistance (DCR) current sensing scheme for multiphase peak current mode controller. A second order RC sensing network amplifies the high frequency sensing signal and also extracts the low frequency signal. The sensing error of traditional DCR current sensing, which caused by the input bias current of the sensing circuit, is cancelled. A time-shared amplifier amplifies the low frequency signals from all the phases, and the outputs are combined with the exaggerated high frequency signals of each phase respectively to rebuild the current sensing signals. Small signal analysis and the design guidelines of the proposed sensing scheme are presented. The proposed method enhances the signal-to-noise ratio of traditional DCR current sensing, improves the phase to phase current balancing and dramatically reduces silicon area of the sensing circuit. The experimental results on the fabricated IC controller show that the controller provides small PWM jittering, tight current balancing and fast dynamic response.
ISSN:2470-6647
DOI:10.1109/APEC42165.2021.9487283