CHIATECH JOURNAL · Registered Version of Record

Design, Small-Signal Modeling and Prototype Implementation of a 24 V-to-19 V PWM Buck Converter with Type-III Voltage-Mode Compensation

1. Shiaondo Kenneth Chia
2. Gbaden Amenger
3. N. Y. Goshwe

Abstract

Background: A 2016 engineering project at the Federal University of Agriculture Makurdi designed and implemented a pulse-width-modulated buck converter to step 24 V DC down to a regulated 19 V output. Objective: This article converts that archived project into a compact, publication-ready engineering paper, reconstructing the power-stage mathematics, voltage-mode feedback loop and Type-III compensation while preserving the documented prototype and simulation evidence. Methods: The archived specifications were audited and re-expressed using continuous-conduction-mode (CCM) equations, small-signal control-to-output modeling, K-factor pole-zero placement and analytical ripple calculations. The source specifies 24 V input, 19 V rated output, 3.5 A, 66.5 W, 30 kHz switching, L = 251 µH, C = 15 µF, capacitor ESR = 10 mΩ and inductor DCR = 2 mΩ. Results: The ideal duty ratio is 0.7917. At the 3.5 A design point the equivalent rated load is 5.43 Ω, while the archived simulation schematic separately uses a nominal 5 Ω test load. The reconstructed inductor ripple is approximately 0.526 A peak-to-peak (15.0% of rated output current), with an analytical output-ripple estimate of about 0.151 V peak-to-peak when capacitive and ESR terms are combined. The LC double-pole frequency is approximately 2.594 kHz and the capacitor-ESR zero approximately 1.061 MHz. The documented Type-III network (R1 = 2.2 kΩ, R2 = 5.9 kΩ, R3 = 38.8 Ω, C1 = 34.2 nF, C2 = 0.6 nF, C3 = 90 nF) is consistent with a voltage-mode compensation strategy that places two zeros around the LC resonance and high-frequency poles above the crossover region. Conclusion: The archived design is technically coherent at its rated point and demonstrates the engineering value of PWM, CCM energy transfer and Type-III loop shaping. The article also identifies legacy reporting inconsistencies that should not be interpreted as new measurements, notably the source wording that labels 19 V and 3.5 A as ripple values.

Keywords: buck converter; DC-DC conversion; pulse-width modulation; voltage-mode control; Type-III compensation; K-factor; small-signal model; continuous conduction mode; power electronics

Licence: CC BY 4.0

Published by CHIA TECH SOLUTIONS AND RESOURCES LIMITED. ISSN assignment remains pending.