🌐 Idioma / Language: English English Português Português Español Español

Monday, November 24, 2025

Symmetrical SMPS 2×50V 350W Using IR2153 and IRF840 - Complete Guide + PCB

Symmetrical SMPS 2×50V 350W Using IR2153 and IRF840
Symmetrical SMPS 2×50V 350W Using IR2153 and IRF840

🌐 You can read this article in: Português | Español

🔧 Who this guide is for: This article is perfect for electronics students, enthusiasts, designers, and hobbyists who want to build a high-power (350W) SMPS switched power supply with excellent cost-benefit ratio. We'll detail every step of the process, from theory to final assembly!

Hello Everyone!

In today's post, we'll dive into the fascinating world of SMPS (Switched-Mode Power Supply), exploring a project based on the IR2153 Integrated Circuit. This 8-pin PWM (Pulse Width Modulation) controller is a true gem for electronics, allowing us to build an excellent quality unregulated switched power supply for various applications.

What makes this project special is the combination of simplicity and performance. With a relatively low cost, we can obtain a robust symmetrical power supply capable of delivering up to 350W of power - ideal for powering audio amplifiers, laboratory power supplies, or other projects that require high symmetrical voltages.

💡 Expert tip: SMPS power supplies like this are up to 85% more efficient than traditional linear power supplies, generating less heat and taking up less space. This makes them ideal for portable applications or where space is limited.

⚡ Understanding the Power Stage

The power stage is the heart of our SMPS power supply, responsible for delivering the necessary energy for your applications. In this project, we use two N-type IRF840 MOSFET transistors, robust components widely available in the market, which receive the PWM pulses from the IR2153 integrated circuit.

The power supply for the IR2153 IC is provided through the 27K 5W power resistor. An important detail is that, in the internal package of this IR2153D IC, there is already a 15.6V Zener diode for protection. However, the current is limited, so we must be careful not to use a resistor R3 with lower resistance, as this would increase the current at the IC input, potentially damaging the Zener and, consequently, the IC.

✓ Attention: If you are using the IR2153D (version with internal diode), there is no need to use the D2 (FR107 or BA159) diode, as this IC already has this component internally. If it's the IR2153 "without the letter D", keep the D2 diode as indicated in the schematic.

Blocking Filters and Protection

At the circuit input, we implement an EMI (Electromagnetic Interference) filter and protection system. We use an NTC Thermistor to limit the peak current during the initial charging of capacitors, avoiding overloads. This same topology can be found in computer AT/ATX power supplies, which demonstrates its effectiveness and reliability.

📚 Learn more: The EMI filter is essential to prevent noise generated by the switching of MOSFETs from returning to the power grid, interfering with other equipment. It also protects the power supply against external noise that could affect its operation.

🔌 Circuit Electrical Schematic

In Figure 2, we present the complete schematic diagram of our Symmetrical SMPS Switched Power Supply, with power up to 350W using the IR2153 Integrated Circuit as PWM controller and IRF840 Power Transistors. This compact circuit is extremely functional and can be adapted for various applications.

Schematic Diagram Symmetrical SMPS 2×50V 350W Using IR2153 and IRF840
Fig 2 - Schematic Diagram Symmetrical SMPS 2×50V 350W Using IR2153 and IRF840

🔍 Circuit analysis: The schematic shows a classic half-bridge configuration, where the IR2153 generates complementary PWM signals to drive the MOSFETs Q1 and Q2. The transformer TR1 receives these pulses and transfers them to the secondary, where they are rectified and filtered to produce the symmetrical output voltages.

🌀 Detailed Guide: Winding the Transformer

The transformer TR1 is a critical component and was salvaged from a scrap ATX power supply. After rewinding, its primary inductance was approximately 6.4 mH, an ideal value for this application.

⚠️ Attention: The transformer core should not have an air gap. Some transformers from ATX power supplies have a gap spacing. If yours has one, you'll need to sand the surfaces until this spacing is completely eliminated, ensuring full contact between the core halves.

Primary Winding Process

The primary winding consists of 40 turns of 0.6 mm super enameled copper wire, configured without Center Tap (center point).

Secondary Winding

The secondary consists of a winding of 28 turns with Center Tap of 0.6 mm super enameled copper wire. This configuration will provide us with symmetrical voltages of approximately ±50V after rectification and filtering.

Filtering Inductors

The inductor L1 / L2 is the same one used in the original ATX power supply and does not require modifications. The inductors L3 and L4, from the output EMI filters, can be wound on ferrite toroidal cores.

For the output inductors, we recommend winding the paired coils on the same toroidal cores, using 0.6 mm super enameled copper wire with 25 turns on each power terminal. This will ensure effective filtering and reduce output ripple.

💡 Practical tip: When winding the inductors, keep the wire always taut and distribute the turns evenly around the core. This will prevent heat buildup at specific points and improve the filter's performance.

🧾 Detailed Materials List

To ensure the success of your project, the quality of components is essential. Below, we present the complete list of materials in an organized way, with clear specifications to facilitate your purchase and avoid errors.

Reference Component Specification Notes
CI1 Integrated Circuit IR2153 or IR2153D PWM Controller
Q1, Q2 Mosfet Transistors IRF840 500V, 8A. Heat sink required.
R1, R2 Resistor 150k (1/4W) Brown, green, yellow
R3 Power Resistor 27K 5W Red, violet, orange. Do not use lower value!
R4 Resistor 10K (1/4W) Brown, black, orange
R5, R6 Resistor 10Ω (1/4W) Brown, black, black. MOSFET gates.
R7, R8 Resistor 22Ω 2W Red, red, black. Discharges Snubber Cap.
D1 Diode Bridge GBJ2510 Input rectification. 1000v 25A.
D2 Fast Diode FR107 or BA159 Do not use with IR2153D (already has internal).
D3 à D6 Fast Diodes MUR460 Output rectification. 600V, 4A.
C1, C2 Polyester Capacitor 470nF - 250Vac Input EMI filter (X type).
C3, C4 Electrolytic Capacitor 680uF - 450V DC bus filter.
C5, C7 Electrolytic Capacitor 100uF - 50V IC power supply (bootstrap).
C6 Ceramic Capacitor 470pF Sets the oscillation frequency.
C8 Polyester Capacitor 2.2uF - 400V Transformer primary coupling.
C9, C10 Electrolytic Capacitor 2200uF - 65V Output filter. Use low ESR.
C11, C12 MKP Ceramic 1nF - 1000V RC Snubber
P1 Potentiometer 100kΩ Fine frequency adjustment (optional).
NTC1 Thermistor Inrush current protection.
L1, L2, L3, L4 Inductors *See details in text EMI and output filters.
TR1 Transformer *See details in text EE or EI core from ATX power supply.
F1 Fuse 3A (solderable) Main overcurrent protection.

🖨️ Printed Circuit Board (PCB) - Optimized Design

To facilitate your assembly and ensure maximum performance and safety, we have prepared a professionally designed printed circuit board (PCB). The layout was optimized to:

  • Wide Traces: To support high currents without overheating.
  • Adequate Separation: Safe distance between high voltage and low voltage parts.
  • Thermal Planning: Strategic positioning of heat-dissipating components.
  • Compatibility: Standard drilling for the listed components.

We are making available for Download all the necessary materials for those who want to assemble with the suggested board: files in webp, PDF for home printing and Gerber files for those who want to send for professional manufacturing.

PCB Symmetrical SMPS 2×50V 350W Using IR2153 and IRF840
Fig. 3 - PCB Symmetrical SMPS 2×50V 350W Using IR2153 and IRF840

📥 Download the Project Files Now!

To download the necessary files for assembling the electronic circuit, simply click on the direct link provided below:

Download Link: PCB Layout, PDF, GERBER, JPG

🤔 Frequently Asked Questions (FAQ) - IR2153 IRF840 Symmetrical SMPS Power Supply

To ensure your project is a success, we've compiled some of the most common questions about the IR2153 and IRF840 Symmetrical Switch-Mode Power Supply.

❓ Can I use this power supply for an audio amplifier? 🔽

Yes, this power supply is excellent for audio amplifiers that require a symmetrical supply, such as class AB or D amplifiers. The low ripple and high current capacity ensure superior sound quality.

❓ What should I do if the power supply doesn't turn on? 🔽

First, check the F1 fuse. Then, with the power supply disconnected from the mains, measure the continuity of the main components. A common mistake is a faulty transformer winding or cold solder joints on the MOSFETs and the IC. Use a lamp in series with the input for a safe test.

❓ Is it necessary to add a fan for cooling? 🔽

For operations at powers close to 350W or for long periods, it is highly recommended. A small 12V fan can be powered by the supply itself (with a 7812 regulator, for example) to keep the MOSFETs and transformer at a safe temperature.

🎉 Conclusion and Next Steps

We've reached the end of this complete guide for building your 350W Symmetrical SMPS Switched Power Supply. With this project, you not only build a powerful tool for your applications but also deepen your knowledge in power electronics, a fundamental and rewarding area.

Always remember to prioritize safety, working carefully and using appropriate protective equipment. The assembly of switched power supplies involves high voltages and can be dangerous if handled incorrectly.

✨ Our Gratitude and Next Steps

We sincerely hope this guide has been useful and enriching for your projects! Thank you for dedicating your time to this content.

Your Feedback is Invaluable:

Have any questions, suggestions, or corrections? Feel free to share them in the comments below! Your contribution helps us refine this content for the entire ElCircuits community.

If you found this guide helpful, spread the knowledge!

🔗 Share This Guide

Best regards,

The ElCircuits Team ⚡

No comments:

Post a Comment