Siripongdee, Surapong
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Preferred name
Siripongdee, Surapong
Alternative Name
siripongdee, Surapong
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Email
surapong.si@kmitl.ac.th
29 results
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Item type:Publication, Synthesis of electronically tunable multifunction biquad filter using voltage differencing differential input buffered amplifiers(2025-02-01); ; ; Biquad filters are commonly used in analog circuits for various purposes in signal processing and communication applications. We synthesize an analog active biquad filter with five types of voltage-mode filtering functions. The filter is synthesized using a parallel passive resistor-inductor-capacitor (RLC) network and unity-gain voltage differencing amplifier. A voltage differencing differential input buffered amplifier (VD-DIBA) is the main active component, and the biquad filter has a three-input single-output (TISO) topology. By replacing the passive inductor and resistor with VD-DIBA-based inductance and resistance simulators with a subtractor, the TISO voltage-mode versatile filter is obtained from two VD-DIBAs, one resistor, and two capacitors connected to the ground. The proposed filter can provide five types of voltage-mode filtering functions: inverting bandpass and lowpass responses as well as noninverting band-stop, high-pass, and all-pass responses. The all-pass filter requires no additional active components. The three input voltage nodes have high impedance, and a low-impedance output voltage node facilitates cascade connections without using additional voltage buffers. In addition, the natural frequency and quality factor can be electronically tuned. The quality factor is controlled without disturbing the passband gain and natural frequency. The proposed filter is simulated and verified experimentally in the Personal Simulation Program with Integrated Circuit Emphasis (PSPICE) and through laboratory tests employing VD-DIBAs implemented using commercially available components. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Single Active Element Based Electronically Controllable Capacitance Multiplier(2022-07-15); ; ; The realization of capacitance multiplier using the versatile active building block, namely voltage differencing differential difference amplifier (VDDDA) is presented in this paper. The realized capacitance multiplier is very simple consisting of one VDDDA, one MOS resistor (RM) and one grounded capacitor which is attractive for integration. The multiplication factor (KC) of the realized circuit can be electronically controlled via the bias current (IB) and control voltage (VC) without the need of any matching condition of active and passive element. Moreover, the multiplication factor can be adjusted to be more or less than one. The performances of the presented capacitance multiplier are verified through Pspice simulation using CMOS VDDDA in 0.18μm TSMC technology with ±0.9V power supplies. The multiplication factor is designed to be KC=2 by choosing VC=0.85V, IB=50μA and C=30 pF. The simulated multiplication factor is around 1.98. The simulated operational frequency range is around three decades (6.16 kHz-8.91MHz). The performances of the proposed circuit are also verified by the experiment using VDDDA implemented from the commercial ICs, AD830 and LM13700 with ±5V power supplies. The experiment is conducted under the same multiplication factor (KC=2) as the simulation by choosing RM=0.27 kω (1% passive resistor), IB=96.2μA and C=1nF. The experimental multiplication factor is around 2.06. The experimental operational frequency range is around three decades (1kHz-1.25MHz). By adjusting the bias current from 17.67μA to 400 μA, the experimental multiplication factor is controllable from 11.47 to 0.48. The percent deviation of the theoretical and experimental multiplication factor is lower than 5% when the value of bias current is greater than 39μA. These deviations stem from the effect of the parasitic capacitance and resistance in VDDDA. Moreover, the application example of the presented capacitance multiplier as the sinusoidal oscillator is presented. The performances of the presented oscillator verified via the experiment are well consistent with theoretical anticipation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Electronically controllable grounded inductance simulators using single commercially available IC: LT1228(2017-06-01); The grounded inductance simulators using available commercially integrated circuit (IC) are proposed in this paper. The three types of active inductor called parallel R and L, series R and L and pure L are achieved. The proposed inductance simulators consist of single available commercially IC from Linear Technology Inc. called LT1228 with a resistor and a capacitor. The tune of inductance and resistance value can be done electronically. The proposed inductance simulators don't require any active and passive component matching condition. The performances of proposed circuit are verified through PSPICE simulation and experiment. To show the usability of the proposed simulators, they are used to realize the sinusoidal oscillator, second order bandpass filter and second order band-reject filter. The workability of these applications is experimented. The results agree well with theoretical expect. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, High input impedance voltage-mode biquad filter using VD-DIBAs(2014-01-01); ; Bajer, JosefThis paper deals with a single-input multipleoutput biquadratic filter providing three functions (lowpass, high-pass and band-pass) based on voltage differencing differential input buffered amplifier (VD-DIBA). The quality factor and pole frequency can be electronically tuned via the bias current. The proposed circuit uses two VD-DIBAs and two grounded capacitors without any external resistors, which is suitable to further develop into an integrated circuit. Moreover, the circuit possesses high input impedance, providing easy voltage-mode cascading. It is shown that the filter structure can be easily extended to multi-input filter without any additional components, providing also all-pass and band-reject properties. The PSPICE simulation results are included, verifying the key characteristics of the proposed filter. The given results agree well with the theoretical presumptions. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Single commercially available ic-based electronically controllable voltage-mode first-order multifunction filter with complete standard functions and low output impedance(2021-11-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Multi-phase structure electrospun CNF@Ag/Mn/Bi/Fe composite nanofiber enhanced supercapacitor behavior(2025-02-15) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A New Method to Synthesise the Sinusoidal Oscillator Based on Series Negative Resistance-Capacitance and its Implementation Using a Single Commercial IC, LT1228(2023-01-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Five-inputs single-output voltage mode universal filter with high input and low output impedance using VDDDAs(2017-01-01); ; Khateb, FabianThe design of analog filter using active building block has been gained significant attention and has become an interesting research topic. A five-inputs single −output voltage-mode universal biquadratic filter using active building block, namely voltage differencing differential difference amplifier (VDDDA) is presented in this paper. The proposed filter consists of two VDDDAs and two grounded capacitors. The presented circuit has high impedance for all input voltage nodes and low impedance for output voltage node which is ideal for cascade in voltage-mode circuit without the use of buffer circuits. It can provide five output voltage functions which are band-pass (BP), low-pass (LP), band-reject (BR), high-pass (HP) and all-pass (AP) responses. For high-pass and band-pass functions, the inverting and non-inverting response can be achieved. The matching condition, the inverting and double gain amplifier are not required which is easy to select the output response by digital method. The natural frequency and quality factor can be electronically tuned that is attractive for microcomputer or microcontroller controllability. To verify the validity of proposed filter, the PSPICE simulation and experimental results using VDDDA constructed from commercially available IC are included. The measured results agree well with theoretical expect. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancing ICT Literacy and Achievement: A TPACK-Based Blended Learning Model for Thai Business Administration Students(2024-05-01); ; The COVID-19 pandemic has heightened the need for 21st century skills, particularly computer and ICT literacy (CICT) in Thailand. This study aimed to develop a TPACK (Technological Pedagogical and Content Knowledge)-based blended learning model (BLM) to enhance CICT skills and academic performance among 179 Business Administration (BA) undergraduates in the 2022 academic year Computer and Information Applications course. Research instruments were designed and evaluated by experts. Over 18 weeks, qualitative and quantitative data were collected, with the qualitative data undergoing content analysis. Descriptive statistics were used to analyze quantitative data, comparing pretests, post-tests, and 2-week retests using a repeated measure ANOVA. One-sample t-tests were used to assess the model’s impact on CICT skills. The results showed a significant score improvement between tests, with the highest mean being seen in the 2-week retest. The BA-TPACK model significantly enhanced CICT skills, exceeding 80%. The students expressed high satisfaction, with the BA-TPACK model effectively enhancing CICT skills and academic achievement, recommending its integration into future computer and information courses. This study’s contribution lies in addressing the pressing need for CICT skills in the ‘new normal’. By developing and implementing a BLM grounded in the TPACK framework, this study not only enhances students’ CICT proficiency but also fills a crucial gap in the literature regarding effective pedagogical approaches to foster 21st century skills. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Feasibility of integrating small-scale liquefied natural gas (LNG) terminal with combined cycle power plant to reduce carbon emissions and costs for data centers(2025-06-01); ; Global data centers are projected to consume 2–3% of global electricity and contribute 8% of carbon emissions by 2030, driven by the rising demand for 5G. In Southeast Asia's tropical climate, cooling data centers presents a challenge, as power plant efficiency drops by 10–20% during summer, when ambient temperatures reach 35–40°C. This study introduces a novel system that integrates a small-scale liquefied natural gas (LNG) receiving terminal with a combined cycle power plant (CCPP) and a data center, designed specifically for tropical climates. The system harnesses LNG cold energy through three configurations: intermediate fluid vaporizer (IFV), Rankine cycle (RC), and direct expansion cycle (DEC), to optimize electricity generation and chilled water production. By reducing the gas turbine inlet temperature from 35°C to 22°C, the system boosts power output by 12.22% and thermal efficiency by 3.84%. Nighttime cooling supports a 3,048-rack data center, resulting in annual savings of $5.50 million and a reduction of 20,304 tons of CO₂ emissions. Switching to gas power plants during summer further increases savings to $7.75 million and cuts emissions by 29,104 tons. An economic analysis shows a payback period of 2.30 years and an internal rate of return (IRR) of 69%. This integrated approach offers an efficient, cost-effective, and environmentally sustainable solution for power generation and data center operation in hot climates.