solderic.com TO-220 packages are ideal for medium-power applications offering a compact form factor and easy heat dissipation, whereas TO-247 packages handle higher power loads with greater thermal performance and enhanced reliability in demanding environments. Explore the rest of the article to discover which package best suits your specific application needs.
Comparison Table
| Feature | TO-220 | TO-247 |
|---|---|---|
| Package Type | Through-hole, three-pin | Through-hole, three or more pins |
| Size | Approx. 10mm x 15mm | Approx. 15mm x 20mm |
| Power Dissipation | Up to 50W (with heatsink) | Up to 150W (with heatsink) |
| Thermal Resistance | ~1.5 degC/W junction-to-case | ~0.5 degC/W junction-to-case |
| Application | Low to medium power devices | Medium to high power devices |
| Mounting | PCB or heatsink mount | PCB or larger heatsink mount |
| Cost | Lower | Higher |
Introduction to Power Transistor Packages
TO-220 and TO-247 are widely used power transistor packages designed for efficient heat dissipation in high-power applications. TO-220 features a smaller, compact design with a typical power dissipation rating around 50-70 watts, making it suitable for moderate power devices. TO-247 offers a larger surface area with higher power dissipation capacity, often exceeding 100 watts, ideal for high-current and high-voltage transistors in industrial and automotive power electronics.
Overview of TO-220 and TO-247
TO-220 and TO-247 are popular semiconductor package types designed for power devices such as transistors and MOSFETs. TO-220 features a compact size with three leads and a metal tab for heat dissipation, suitable for medium power applications up to around 50W. TO-247 offers a larger form factor with three or more leads, enhanced thermal performance, and higher current handling capacity, making it ideal for high-power applications exceeding 100W.
Physical Dimensions and Design Differences
The TO-220 package features a compact design with dimensions typically around 10mm x 15mm, making it suitable for medium power applications and easier integration into standard printed circuit boards. TO-247, by contrast, boasts larger physical dimensions, approximately 15mm x 20mm, allowing for higher power dissipation due to its increased surface area and thermal management capabilities. Your choice between TO-220 and TO-247 hinges on the required power handling and available board space, with TO-247 offering superior heat dissipation through its beefier design.
Thermal Performance Comparison
TO-247 packages exhibit superior thermal performance compared to TO-220, largely due to their larger surface area and thicker copper lead frames that enhance heat dissipation. The TO-247's higher power handling capability is often favored in high-current applications where efficient thermal management is critical. Thermal resistance from junction to case (RthJC) for TO-247 typically ranges from 0.3 to 0.6 degC/W, whereas TO-220 values are usually around 1.0 to 3.0 degC/W, indicating better heat conduction in TO-247 components.
Maximum Power Dissipation Capabilities
The TO-247 package offers significantly higher maximum power dissipation capabilities compared to the TO-220, often exceeding 100 watts under proper cooling conditions, whereas TO-220 typically handles up to 40-50 watts. Enhanced thermal performance in TO-247 is attributed to its larger die size and improved heat spreader design, making it suitable for high-power applications like power transistors and IGBTs. Efficient heat sinking and airflow further optimize the power dissipation capacity of TO-247 in demanding industrial and automotive electronics.
Electrical Characteristics and Ratings
TO-247 packages typically support higher current ratings and power dissipation compared to TO-220, making them ideal for applications requiring robust thermal management and higher loads. Electrical characteristics such as maximum voltage and current are generally superior in TO-247 due to its larger size and enhanced heat sinking capabilities. TO-220 is preferred for moderate power scenarios with lower current ratings and easier mounting, providing a balance between compactness and thermal performance.
Applications and Use Cases
TO-220 packages are commonly used in low to medium power applications such as voltage regulators, audio amplifiers, and power transistors due to their compact size and efficient heat dissipation. TO-247 packages are preferred in high-power applications like industrial motor drives, high-current power supplies, and RF amplifiers because of their superior thermal management and higher current handling capability. Engineers select TO-220 for cost-sensitive designs requiring moderate performance, while TO-247 suits demanding environments requiring robust thermal and electrical performance.
Mounting and Heat Sink Considerations
TO-220 and TO-247 packages differ significantly in mounting and heat sink capabilities, with TO-247 offering a larger surface area that enhances heat dissipation for high-power applications. Proper mounting techniques for TO-247 often involve using insulated or direct contact heat sinks with thermal interface materials to optimize thermal transfer and prevent electrical shorts. Your choice between TO-220 and TO-247 should consider not only the power rating but also the thermal management requirements to ensure reliable device operation under load.
Cost and Availability Analysis
TO-220 packages generally offer lower costs and higher availability due to widespread usage in consumer electronics and power management applications, making them highly accessible for large-scale production. In contrast, TO-247 packages, designed for higher power handling and thermal performance, tend to be more expensive and less commonly stocked, often reserved for specialized industrial or high-performance circuits. Market trends indicate TO-220 components have a broader vendor base and faster procurement times, while TO-247 parts may face longer lead times and premium pricing associated with their enhanced specifications.
Choosing Between TO-220 and TO-247
Choosing between TO-220 and TO-247 packages depends on your device's power dissipation and current handling requirements. The TO-220 package is suitable for medium power applications with moderate thermal dissipation, while the TO-247 package offers superior thermal performance and is ideal for high-power devices due to its larger size and better heat sinking capabilities. Ensure your design accommodates the physical dimensions and mounting options to optimize your circuit's reliability and efficiency.
TO-220 vs TO-247 Infographic
