Analysis and Design of a Current-Mode PWM Buck Converter Adopting the Output-Voltage Independent Second-Order Slope Compensation Scheme

Background: The original filter including grounded or virtual ground capacitors can be synthesized by using the NAM expansion. However, so far the filters including floating capacitor, such as Sallen-Key filter, have not been synthesized by means of the NAM expansion. This is a problem to be researched further. Methods: By using the adjoint network theory, the Sallen-Key filter including floating capacitor first is turned into a current-mode one, which includes a grounded capacitor and a virtual ground capacitor. Then the node admittance matrix, after derived, is extended by using NAM expansion. Results: At last, one VDTA Sallen-Key filter is received. It employs single compact VDTA and two grounded capacitors. Conclusion: A Butterworth VDTA second-order frequency filter based on Sallen-Key topology with fo = 100kHz, HLP = -HBP=1, is designed.

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A Current-Mode Four-Phase Synchronous Buck Converter with Dynamic Dead-Time Control

IEEE Access ◽

10.1109/access.2021.3085826 ◽

2021 ◽

pp. 1-1

Author(s):

Jun Tang ◽

Tian Guo ◽

Jung Sik Kim ◽

Jeongjin Roh

Keyword(s):

Dead Time ◽

Current Mode ◽

Buck Converter ◽

Time Control ◽

A Current

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Analysis and Design for Output Voltage Regulation in Constant-on-Time-Controlled Fly-Buck Converter

Electronics ◽

10.3390/electronics10161886 ◽

2021 ◽

Vol 10 (16) ◽

pp. 1886

Author(s):

Younghoon Cho ◽

Paul Jang

Keyword(s):

Output Voltage ◽

Voltage Regulation ◽

Design Guidelines ◽

Buck Converter ◽

Design Guideline ◽

Analysis And Design ◽

Flyback Converter ◽

Auxiliary Power ◽

Primary Output ◽

Output Capacitor

Fly-buck converter is a multi-output converter with the structure of a synchronous buck converter structure on the primary side and a flyback converter structure on the secondary side, and can be utilized in various applications due to its many advantages. In terms of control, the primary side of the fly-buck converter has the same structure as a synchronous buck converter, allowing the constant-on-time (COT) control to be applied to the fly-buck converter. However, due to the inherent energy transfer principle, the primary-side output voltage regulation of COT controlled fly-buck converters may be poor, which can deteriorate the overall converter performance. Therefore, the primary output capacitor must be carefully designed to improve the voltage regulation characteristics. In this paper, a theoretical analysis of the output voltage regulation in COT controlled fly-buck converter is conducted, and based on this, a design guideline for the primary output capacitor considering the output voltage regulation is presented. The validity of the analysis and design guidelines was verified using a 5 W prototype of the COT controlled fly-buck converter for telecommunication auxiliary power supply.

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COMPLEX DYNAMICS AND FAST-SLOW SCALE INSTABILITY IN CURRENT-MODE CONTROLLED BUCK CONVERTER WITH CONSTANT CURRENT LOAD

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127413500624 ◽

2013 ◽

Vol 23 (04) ◽

pp. 1350062 ◽

Cited By ~ 10

Author(s):

GUOHUA ZHOU ◽

BOCHENG BAO ◽

JIANPING XU

Keyword(s):

Complex Dynamics ◽

Period Doubling ◽

Current Mode ◽

Input Voltage ◽

Second Order ◽

Buck Converter ◽

Constant Current ◽

Current Load ◽

Time Model ◽

Conduction Mode

The complex dynamics and coexisting fast-slow scale instability in current-mode controlled buck converter with constant current load (CCL), operating in both continuous conduction mode (CCM) and discontinuous conduction mode (DCM), are investigated in this paper. Via cycle-by-cycle computer simulation and experimental measurement of current-mode controlled buck converter with CCL, it is found that a unique fast-slow scale instability exists in the second-order switching converter. It is also found that a unique period-doubling accompanied by Neimark–Sacker bifurcation exists in this simple second-order converter, which is different from period-doubling or Neimark–Sacker bifurcations reported previously. Based on a nonlinear discrete-time model and the corresponding Jacobian, the effects of CCL and input voltage on the dynamics of current-mode controlled buck converter are investigated and verified theoretically. Fixed point analysis for slow-scale low-frequency oscillation is also given to verify the dynamics and the coexisting fast-slow scale instability.

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