scholarly journals Dynamic Modeling and Closed-Loop Control of a Tapped Inductor Buck Converter

2021 ◽  
Author(s):  
Siripan Trakuldit ◽  
Chanin Bunlaksananusorn
Keyword(s):  
Dynamic Modeling ◽  
Transient Response ◽  
Output Voltage ◽  
Closed Loop ◽  
High Efficiency ◽  
Buck Converter ◽  
Closed Loop Control ◽  
Voltage Step ◽  
Loop Control ◽  
Step Down

Modern smart electronic and information technology (IT) devices require a low DC voltage for operation. The low supply voltage is typically provided by a dedicated DC−DC converter by stepping down the system’s bus voltage (e.g., 12 V). It is essential that the converter possesses a large voltage step-down gain and, at the same time, operates at high efficiency. A tapped inductor buck converter (TIBC) is a topology that has a potential to meet these requirements. It has a simple circuit structure and high efficiency similar to a buck converter, but can give a larger voltage step-down gain. This paper presents a dynamic modeling and closed-loop control of a TIBC. The state space averaging (SSA) method is adopted for the dynamic modeling to derive small-signal transfer functions of the converter. Based on the duty-cycle-to-output voltage transfer function, a closed-loop control is designed to keep the converter’s output voltage constant. To verify the design, a prototype TIBC with closed-loop control is implemented. Experimental results show that the prototype converter has good output voltage regulation and fast transient response when subject to a step load. The effect of the crossover frequency and phase margin on the converter’s transient response is also illustrated.

scholarly journals Design and Implementation of an Active Clamped Full Wave Quasi Resonant ZCS Boost Converter

2019 ◽  
Vol 8 (2S5) ◽  
pp. 66-72
Keyword(s):  
Power Factor ◽  
Output Voltage ◽  
Closed Loop ◽  
High Efficiency ◽  
Voltage Regulation ◽  
Boost Converter ◽  
Switching Frequency ◽  
Closed Loop Control ◽  
Loop Control ◽  
Full Wave

This paper presents a closed loop control of an active-clamped full-wave quasi-resonant boost converter with zero-current-switching (ZCS) for power factor correction. Possibility to incorporate higherswitching frequency and has some potency to reduce switching losses. Power factor improvement and high efficiency is achieved with a constant output voltage and DC output voltage is regulated by using closed loop control .The concept of the proposed switchingscheme results lesser switching loss, higher efficiency, possibility to have higher switching frequency, and has potential to reduce converter's conducted EMI. This paper also presents voltage regulation using closed loop system and the simulation results are verified.

A HIGH EFFICIENCY ADAPTIVE CURRENT MODE STEP-UP/STEP-DOWN DC–DC CONVERTER WITH FOUR MODES FOR SMOOTH TRANSITION

2014 ◽  
Vol 23 (07) ◽  
pp. 1450097 ◽  
Author(s):  
YANZHAO MA ◽  
SHAOXI WANG ◽  
SHENGBING ZHANG ◽  
XIAOYA FAN
Keyword(s):  
Transient Response ◽  
Output Voltage ◽  
High Efficiency ◽  
Current Mode ◽  
Smooth Transition ◽  
Maximum Efficiency ◽  
Cmos Process ◽  
Voltage Ripple ◽  
Transition Modes ◽  
Step Down

This paper presents a current mode step-up/step-down DC–DC converter with high efficiency, small output voltage ripple, and fast transient response. The control scheme adaptively configures the converter into the proper operation mode. The efficiency is improved by reducing the switching loss, wherein the converter operates like a buck or boost converter, and conduction loss, wherein the average inductor current is reduced in transition modes. The output voltage ripple is significantly reduced by incorporating two constant time transition modes. A fast line transient response is achieved with small overshoot and undershoot voltage. An adaptive substrate selector (ASS) is introduced to dynamically switch the substrate of PMOS power transistors to the highest on-chip voltage. A lossless self-biased current sensor with high-speed and high-accuracy is also achieved. The proposed converter was designed with a standard 0.5 μm CMOS process, and can regulate an output voltage within the input voltage ranged from 2.5 V to 5.5 V. The maximum load current is 600 mA, and the maximum efficiency is 94%. The output voltage ripple is less than 15 mV in all operation modes.

scholarly journals A Detection Circuit for Improving the Unloading Transient Performance of the COT Controller

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2333
Author(s):  
Xi Zhang ◽  
Tianshi Wang ◽  
Bocheng Bao
Keyword(s):  
Transient Response ◽  
Output Voltage ◽  
Buck Converter ◽  
Control Technique ◽  
Time Interval ◽  
Transient Performance ◽  
Load Step ◽  
Light Load ◽  
Detection Circuit ◽  
Step Down

Fast load transient response and high light-load efficiency are two key features of the constant on-time (COT) control technique that has been widely used in numerous applications, such as for voltage regulators and point-of-load converters. However, when load step-down occurs during an on-time interval, the COT controller cannot respond until the COT interval expires. This delay causes an additional output voltage overshoot, resulting in unloading transient performance limitation. To eliminate the delay and improve the unloading transient response of the COT controller, a load step-down detection circuit is proposed based on capacitor current COT (CC-COT) control. In the detection circuit, the load step-down is monitored by comparing the measured capacitor current with the preset threshold voltage. Once the load step-down is monitored, the on-time is promptly truncated and the switch is turned off. With the proposed detection circuit, the CC-COT-controlled buck converter can monitor the load step-down without any delay and obtain less output voltage overshoot when the load step-down occurs during the on-time interval. PSIM circuit simulations are employed to demonstrate the feasibility of the detection circuit.

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