scholarly journals On-chip current sensing circuit for current-limited minimum off-time PFM boost converter

2009 ◽  
Author(s):  
Yeong-Seuk Kim ◽  
Bo-Mi No ◽  
Jun-Sik Min ◽  
Said Al-Sarawi ◽  
Derek Abbott
Keyword(s):  
Boost Converter ◽  
Current Sensing ◽  
On Chip ◽  
Off Time

On-Chip Compensated Wide Output Range Boost Converter with Fixed-Frequency Adaptive Off-Time Control for LED Driver Applications

2015 ◽  
Vol 30 (4) ◽  
pp. 2096-2107 ◽  
Author(s):  
Lin Cheng ◽  
Jinhua Ni ◽  
Yao Qian ◽  
Minchao Zhou ◽  
Wing-Hung Ki ◽  
...  
Keyword(s):  
Boost Converter ◽  
Fixed Frequency ◽  
Led Driver ◽  
Time Control ◽  
On Chip ◽  
Off Time

scholarly journals Starter for Voltage Boost Converter to Harvest Thermoelectric Energy for Body-Worn Sensors

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4092
Author(s):  
Grzegorz Blakiewicz ◽  
Jacek Jakusz ◽  
Waldemar Jendernalik
Keyword(s):  
Threshold Voltage ◽  
Low Voltage ◽  
Boost Converter ◽  
Mos Transistors ◽  
Weak Inversion ◽  
Thermoelectric Energy ◽  
On Chip ◽  
Voltage Swing ◽  
High Output Voltage ◽  
High Output

This paper examines the suitability of selected configurations of ultra-low voltage (ULV) oscillators as starters for a voltage boost converter to harvest energy from a thermoelectric generator (TEG). Important properties of particularly promising configurations, suitable for on-chip implementation are compared. On this basis, an improved oscillator with a low startup voltage and a high output voltage swing is proposed. The applicability of n-channel native MOS transistors with negative or near-zero threshold voltage in ULV oscillators is analyzed. The results demonstrate that a near-zero threshold voltage transistor operating in the weak inversion region is most advantageous for the considered application. The obtained results were used as a reference for design of a boost converter starter intended for integration in 180-nm CMOS X-FAB technology. In the selected technology, the most suitable transistor available with a negative threshold voltage was used. Despite using a transistor with a negative threshold voltage, a low startup voltage of 29 mV, a power consumption of 70 µW, and power conversion efficiency of about 1.5% were achieved. A great advantage of the proposed starter is that it eliminates a multistage charge pump necessary to obtain a voltage of sufficient value to supply the boost converter control circuit.

scholarly journals Active Clamp Boost Converter with Blanking Time Tuning Considered

2021 ◽  
Vol 11 (2) ◽  
pp. 860
Author(s):  
Yeu-Torng Yau ◽  
Kuo-Ing Hwu ◽  
Yu-Kun Tai
Keyword(s):  
Boost Converter ◽  
Zero Current Switching ◽  
Active Clamp ◽  
Overall Efficiency ◽  
Auto Tuning ◽  
Voltage Spike ◽  
Resonant Inductor ◽  
Off Time ◽  
Conduction Mode ◽  
Time Point

An active clamp boost converter with blanking time auto-tuned is presented herein, and this is implemented by an additional auxiliary switch, an additional resonant inductor, and an additional active clamp capacitor as compared with the conventional boost converter. In this structure, both the main and auxiliary switches have zero voltage switching (ZVS) turn-on as well as the output diode has zero current switching (ZCS) turn-off, causing the overall efficiency of the converter to be upgraded. Moreover, as the active clamp circuit is adopted, the voltage spike on the main switch can be suppressed to some extent whereas, because of this structure, although the input inductor is designed in the continuous conduction mode (CCM), the output diode can operate with ZCS turn-off, leading to the resonant inductor operating in the discontinuous conduction mode (DCM), hence there is no reverse recovery current during the turn-off period of the output diode. Furthermore, unlike the existing soft switching circuits, the auto-tuning technique based on a given look-up table is added to adjust the cut-off time point of the auxiliary switch to reduce the current flowing through the output diode, so that the overall efficiency is upgraded further. In this paper, basic operating principles, mathematic deductions, potential designs, and some experimental results are given. To sum up, the novelty of this paper is ZCS turn-off of the output diode, DCM operation of the resonant inductor, and auto-tuning of cut-off time point of the auxiliary switch. In addition, the efficiency of the proposed converter can be up to 96.9%.

20 kV 4H-SiC N-IGBTs

2014 ◽  
Vol 778-780 ◽  
pp. 1030-1033 ◽  
Author(s):  
Sei Hyung Ryu ◽  
Craig Capell ◽  
Charlotte Jonas ◽  
Michael J. O'Loughlin ◽  
Jack Clayton ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Leakage Current ◽  
Supply Voltage ◽  
Boost Converter ◽  
Power Switching ◽  
Switching Device ◽  
Blocking Voltage ◽  
Off Time ◽  
Drift Layer ◽  
Stop Buffer

A 1 cm x 1 cm 4H-SiC N-IGBT exhibited a blocking voltage of 20.7 kV with a leakage current of 140 μA, which represents the highest blocking voltage reported from a semiconductor power switching device to this date. The device used a 160 μm thick drift layer and a 1 μm thick Field-Stop buffer layer, and showed a VF of 6.4 V at an IC of 20 A, and a differential Ron,sp of 28 mΩ-cm2. Switching measurements with a supply voltage of 8 kV were performed, and a turn-off time of 1.1 μs and turn-off losses of 10.9 mJ were measured at 25°C, for a 8.4 mm x 8.4 mm device with 140 μm drift layer and 2 μm F-S buffer layer. The turn-off losses were reduced by approximately 50% by using a 5 μm F-S buffer layer. A 55 kW, 1.7 kV to 7 kV boost converter operating at 5 kHz was demonstrated using the 4H-SiC N-IGBT, and an efficiency value of 97.8% was reported.

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