Analysis of Load Current Ripples in a Five Level Buck Converter

2021 ◽  
Author(s):  
Teo Hong Liang ◽  
Manickam Ramasamy ◽  
Mohamad Khan Afthan Ahmed Khan
Keyword(s):  
Buck Converter ◽  
Load Current ◽  
Current Ripples

Analysis of load current ripples in a four level Buck Converter

2014 ◽  
Author(s):  
Syukri Bin Idham Halis ◽  
M.K.A. Ahamed Khan ◽  
Siti Nor Baizura bt Zawawi ◽  
Rohaizah Bt Mohd Ghazali ◽  
I. Elamvazuthi
Keyword(s):  
Buck Converter ◽  
Load Current ◽  
Current Ripples

scholarly journals A Low EMI DC-DC Buck Converter with a Triangular Spread-Spectrum Mechanism

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 856
Author(s):  
Jing-Yuan Lin ◽  
Yi-Chieh Hsu ◽  
Yo-Da Lin
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Output Voltage ◽  
Buck Converter ◽  
Circuit Board ◽  
System Stability ◽  
Maximum Efficiency ◽  
Load Current ◽  
Voltage Range ◽  
Switching Regulators

In this paper, a triangular spread-spectrum mechanism is proposed to suppress the electromagnetic interference (EMI) of a DC-DC buck converter. The proposed triangular spread-spectrum mechanism, which is implemented in the chip, can avoid modifying the printed circuit board of switching regulators. In addition, a lower ripple of output voltage of switching regulators and a better system stability can be realized by the inductive DC resistance (DCR) current sensing circuit. The chip is fabricated by using TSMC 0.18-μm 1P6M CMOS technology. The chip area including PADs is 1.2 × 1.15 mm2. The input voltage range is 2.7~3.3 V and the output voltage is 1.8 V. The maximum load current is 700 mA. The off-chip inductor and capacitor are 3.3 μH and 10 μF, respectively. The experimental results demonstrate that the maximum spur of the proposed DC-DC buck converter with the triangular spread-spectrum mechanism improves to 14dBm. Moreover, the transient recovery time of step-up and step-down loads are both 5 μs. The measured maximum efficiency is 94% when the load current is 200 mA.

scholarly journals A Fully Integrated Bluetooth Low-Energy Transceiver with Integrated Single Pole Double Throw and Power Management Unit for IoT Sensors

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2420 ◽  
Author(s):  
Sung Jin Kim ◽  
Dong Gyu Kim ◽  
Seong Jin Oh ◽  
Dong Soo Lee ◽  
Young Gun Pu ◽  
...  
Keyword(s):  
Low Power ◽  
Power Management ◽  
Low Noise ◽  
Buck Converter ◽  
Low Energy ◽  
Management Unit ◽  
Load Current ◽  
Bluetooth Low Energy ◽  
Current Consumption ◽  
Power Management Unit

This paper presents a low power Gaussian Frequency-Shift Keying (GFSK) transceiver (TRX) with high efficiency power management unit and integrated Single-Pole Double-Throw switch for Bluetooth low energy application. Receiver (RX) is implemented with the RF front-end with an inductor-less low-noise transconductance amplifier and 25% duty-cycle current-driven passive mixers, and low-IF baseband analog with a complex Band Pass Filter(BPF). A transmitter (TX) employs an analog phase-locked loop (PLL) with one-point GFSK modulation and class-D digital Power Amplifier (PA) to reduce current consumption. In the analog PLL, low power Voltage Controlled Oscillator (VCO) is designed and the automatic bandwidth calibration is proposed to optimize bandwidth, settling time, and phase noise by adjusting the charge pump current, VCO gain, and resistor and capacitor values of the loop filter. The Analog Digital Converter (ADC) adopts straightforward architecture to reduce current consumption. The DC-DC buck converter operates by automatically selecting an optimum mode among triple modes, Pulse Width Modulation (PWM), Pulse Frequency Modulation (PFM), and retention, depending on load current. The TRX is implemented using 1P6M 55-nm Complementary Metal–Oxide–Semiconductor (CMOS) technology and the die area is 1.79 mm2. TRX consumes 5 mW on RX and 6 mW on the TX when PA is 0-dBm. Measured sensitivity of RX is −95 dBm at 2.44 GHz. Efficiency of the DC-DC buck converter is over 89% when the load current is higher than 2.5 mA in the PWM mode. Quiescent current consumption is 400 nA from a supply voltage of 3 V in the retention mode.

scholarly journals Efficiency of Synchronous and Asynchronous Buck-Converter at Low Output Current.

2019 ◽  
Vol 27 (2) ◽  
pp. 194-206
Author(s):  
Ismael Khaleel Murad
Keyword(s):  
Duty Cycle ◽  
Buck Converter ◽  
Voltage Regulator ◽  
Switching Frequency ◽  
Output Current ◽  
Load Current ◽  
Small Load ◽  
Step Down ◽  
Conduction Mode ◽  
Continuous Conduction Mode

In this paper both synchronous and asynchronous buck-converter were designed to work in continuous conduction mode “CCM” and to deliver small load current. Then the two topologies were tested in terms of efficiency at small load current by use of  different values of switching frequencies (range from 150 KHz to 1MHz) and three separated values of duty-cycle (0.4, 0.6 and 0.8).   Obtained results turns out that efficiency of both synchronous and asynchronous buck-converter “switching step-down voltage regulator” responds in a negative manner to the increase in the switching frequency. However, this impact is being stronger in synchronous topology because of magnifying effect of losses related to switching frequency compared to those related to conduction when working at small load currents; this behavior makes obtained efficiency of both topologies in convergent levels when they operated to deliver small output current especially when working with higher switching frequencies. Larger duty-cycle can rise up the efficiency of both topologies.

A novel adaptive hysteresis DC-DC buck converter for portable devices

2019 ◽  
pp. 807-818 ◽  
Author(s):  
SUNG SIK PARK ◽  
JU SANG LEE ◽  
SANG DAE YU
Keyword(s):  
Circuit Simulation ◽  
Reverse Current ◽  
Buck Converter ◽  
Portable Devices ◽  
Cmos Process ◽  
Load Current ◽  
Current Sensing ◽  
Zero Current ◽  
Detection Circuit ◽  
A New Technique

This paper presents a new technique that adjusts the hysteresis window depending on the variations in load current caused by a voltage-mode circuit to reduce the voltage and current ripples. Moreover, a compact current-sensing circuit is used to provide an accurate sensing signal for achieving fast hysteresis window adjustment. In addition, a zero-current detection circuit is also proposed to eliminate the reverse current at light loads. As a result, this technique reduces the voltage ripple below 8.08 mVpp and the current ripple below 93.98 mApp for a load current of 500 mA. Circuit simulation is performed using 0.18 μm CMOS process parameters.

Proton Exchange Membrane Fuel Cell Emulator Using PI Controlled Buck Converter

2017 ◽  
Vol 8 (1) ◽  
pp. 462 ◽  
Author(s):  
Himadry Shekhar Das ◽  
Chee Wei Tan ◽  
AHM Yatim ◽  
Nik Din Bin Muhamad
Keyword(s):  
Fuel Cell ◽  
Alternative Energy ◽  
Proton Exchange Membrane ◽  
Buck Converter ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Load Current ◽  
Energy Technologies ◽  
Exchange Membrane ◽  
Electrochemical Model

Alternative energy technologies are being popular for power generation applications nowadays. Among others, Fuel cell (FC) technology is quite popular. However, the FC unit is costly and vulnerable to any disturbances in input parameters. Thus, to perform research and experimentation, Fuel cell emulators (FCE) can be useful. FCEs can replicate actual FC behavior in different operating conditions. Thus, by using it the application area can be determined. In this study, a FCE system is modelled using MATLAB/Simulink®. The FCE system consists of a buck DC-DC converter and a proportional integral (PI) based controller incorporating an electrochemical model of proton exchange membrane fuel cell (PEMFC). The PEMFC model is used to generate reference voltage of the controller which takes the load current as a requirement. The characteristics are compared with Ballard Mark V 5kW PEMFC stack specifications obtained from the datasheet. The results show that the FCE system is a suitable replacement of real PEMFC stack and can be used for research and development purpose.

scholarly journals Sliding-Mode Control of a Dc/Dc Postfilter for Ripple Reduction and Efficiency Improvement in POL Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
S. I. Serna-Garcés ◽  
R. E. Jiménez ◽  
C. A. Ramos-Paja
Keyword(s):  
Sliding Mode ◽  
Buck Converter ◽  
Sliding Mode Controller ◽  
Buck Converters ◽  
Efficiency Improvement ◽  
Load Current ◽  
Correct Operation ◽  
Current Harmonics ◽  
Ripple Reduction ◽  
Classical Point

This paper proposes an active postfilter based on two Buck converters, connected in parallel, operating in complementary interleaving. In such a configuration the ripple in the load current could be virtually eliminated to improve the power quality in comparison with classical Point-Of-Load (POL) regulators based on a single Buck converter. The postfilter is designed to isolate the load from the main Buck regulator, leading to the proposed three-converter structure named BuckPS. The correct operation of the postfilter is ensured by means of a sliding-mode controller. Finally, the proposed solution significantly reduces the current harmonics injected into the load, and at the same time, it improves the overall electrical efficiency. Such characteristics are demonstrated by means of analytical results and illustrated using numerical results.

scholarly journals Fractional analog scheme for efficient stabilization of a synchronous buck converter

2020 ◽  
Vol 71 (2) ◽  
pp. 116-121
Author(s):  
Watson Valele ◽  
Robsen Virambath ◽  
Utkal Mehta ◽  
Sheikh Azid
Keyword(s):  
Fractional Order ◽  
Input Voltage ◽  
Buck Converter ◽  
Future Directions ◽  
Parameter Variations ◽  
Improved Performance ◽  
Fractional Order Controller ◽  
And Control ◽  
Current Ripples ◽  
Fractional Controller

AbstractThis paper presents the design and control of power electronic synchronous buck converter. Even though a synchronous buck converter is more popular and more widely available, it is not always efficient as nonsynchronous. Firstly, the inputoutput linearization from the state space averaging of the converter is studied, after which a small AC signal analysis is introduced to obtain the dynamic transfer function. All the parameters of the converter are calculated based on the output voltage, current ripples as well as the input voltage. For robustness, the controller is implemented by comparing the response of integer order with non-integer (fractional) order controller, simply known as fractional order controller (FOC). The fractional order derivative is implemented from the Oustaloup approximation and the controller parameters are being tuned using Nelder Mead approximation bases on a system model. It is shown that the FOC performance is comparatively better in presence of the load disturbances and parameter variations. The experimental study with the real-time fractional PI is possible to make for a stand-alone embedded application using FPAA. The proposed technique does not require any digitization of the signal, so it can be easy to implement with improved performance. The effectiveness of the analog controller is discussed, giving some future directions to adopt the new fractional controller.

scholarly journals Adaptive On-Time Buck Converter with Wave Tracking Reference Control for Output Regulation Accuracy

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3809
Author(s):  
Pang-Jung Liu ◽  
Mao-Hui Kuo
Keyword(s):  
Output Voltage ◽  
Output Regulation ◽  
Buck Converter ◽  
Maximum Efficiency ◽  
Frequency Variation ◽  
Switching Frequency ◽  
Maximum Output ◽  
Equivalent Series Resistance ◽  
Load Current ◽  
Dc Offset

A ripple-based constant on-time (RBCOT) buck converter with a virtual inductor current ripple (VICR) control can relax the stability constraint of large equivalent series resistance (ESR) at an output capacitor, but output regulation accuracy deteriorates due to the issue with output DC offset. Thus, this paper proposes a wave tracking reference (WTR) control to improve converter stability with low ESR and concurrently eliminate output DC offset on the regulated output voltage. Moreover, an adaptive on-time (AOT) circuit is presented to suppress the switching frequency variation with load current changes in continuous conduction mode. A prototype chip was fabricated in 0.35 µm CMOS technology for validation. The measurement results demonstrate that the maximum output DC offset is 4.1 mV and the output voltage ripple is as small as 3 mV. Furthermore, the switching frequency variation with the AOT circuit is 11 kHz when load current changes from 50 mA to 500 mA, and the measured maximum efficiency is 90.9% for the maximum output power of 900 mW.

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