solderic.com TO-220 resistors offer compact size and sufficient power dissipation for moderate applications, while TO-247 resistors provide higher power handling capability and better thermal performance ideal for heavy-duty circuits. Explore the full article to determine which resistor suits your electronic needs best.
Comparison Table
| Feature | TO-220 Resistor | TO-247 Resistor |
|---|---|---|
| Package Size | Smaller, compact | Larger, bulkier |
| Power Dissipation | Up to 50W (with heatsink) | Up to 75W or higher (with heatsink) |
| Thermal Resistance | Lower thermal resistance due to smaller size | Better thermal performance; handles higher heat |
| Mounting | Single-hole mount design | Single-hole mount; larger tab area for heat sink |
| Typical Applications | Medium power regulators, general-purpose resistors | High power resistors, industrial power electronics |
| Current Handling | Moderate current load | Higher current capability |
| Cost | Lower cost | Higher cost |
Introduction to TO-220 and TO-247 Resistors
TO-220 and TO-247 resistors differ primarily in their thermal dissipation capabilities and physical dimensions, with TO-247 providing higher power handling due to its larger size and improved heat sinking options. The TO-220 package is commonly used for moderate power resistors in applications requiring compact form factors, while TO-247 suits high-power scenarios demanding enhanced cooling. Your choice between these resistor types should consider the power rating and thermal management requirements of your electronic circuit.
Physical Dimensions and Package Design
The TO-220 resistor package features compact physical dimensions typically around 10 mm width and 15 mm length, designed for efficient heat dissipation with a single mounting hole. In contrast, the TO-247 resistor package is larger, measuring approximately 20 mm by 25 mm, enabling handling of higher power ratings due to its increased surface area and improved thermal management. The TO-247 design incorporates a more robust mold and a larger copper base plate, enhancing current capacity and facilitating better mechanical stability in high-power applications.
Power Dissipation Capabilities
TO-247 resistors offer significantly higher power dissipation capabilities compared to TO-220 resistors, typically handling up to 50 watts or more versus the TO-220's 15 to 25 watts range. The larger surface area and improved thermal characteristics of TO-247 packages enable more efficient heat dissipation, making them suitable for high-power applications. When selecting a resistor for your circuit, consider the TO-247's superior power capacity to ensure reliable performance under heavy load conditions.
Thermal Management and Heat Sinks
TO-247 resistors provide superior thermal management compared to TO-220 resistors due to their larger surface area and enhanced heat dissipation capabilities. The TO-247 package supports larger, more efficient heat sinks, enabling better temperature regulation under high power conditions. Optimizing your circuit's thermal performance often involves selecting TO-247 resistors when managing significant heat loads to ensure reliability and longevity.
Electrical Performance Differences
TO-247 resistors offer superior electrical performance compared to TO-220 resistors due to their larger package size, which allows for better heat dissipation and higher power ratings reaching up to 200W, while TO-220 variants typically handle around 50W to 75W. The improved thermal management in TO-247 resistors helps maintain lower resistance drift and greater stability under heavy loads, enhancing overall reliability in high-current applications. Choosing your resistor based on these performance parameters ensures optimal efficiency and longevity in power electronics.
Applications and Typical Use Cases
TO-220 resistors are commonly used in moderate power applications such as voltage regulation, power supplies, and small motor controllers where efficient heat dissipation is required but space is limited. TO-247 resistors handle higher power ratings and thermal dissipation, making them ideal for heavy-duty industrial equipment, high-current power amplifiers, and large-scale power conversion systems. Selecting the right package impacts Your device's reliability by matching the resistor's thermal management capabilities to the operational demands.
Mounting Techniques and Compatibility
TO-220 resistors feature a compact package with a single mounting hole, enabling easy attachment to heat sinks or PCBs using screws or clips, making them suitable for moderate power dissipation applications. TO-247 resistors offer a larger, more robust design with improved thermal management and dual mounting holes, allowing for more secure fixation and compatibility with high-power heat sinks. Your choice depends on the power requirements and mechanical stability needed, as TO-247 provides enhanced mounting flexibility for demanding applications compared to the simpler TO-220 format.
Cost Comparison and Availability
TO-220 resistors generally have lower costs due to simpler packaging and widespread availability in standard electronic component suppliers, making them ideal for budget-sensitive projects. TO-247 resistors typically cost more because of their larger size, higher power handling capacity, and less common use, which can limit availability and increase lead times. You should consider your power requirements and budget constraints when choosing between these resistor packages to ensure optimal cost-effectiveness.
Reliability and Durability Factors
TO-247 resistors generally offer higher reliability and durability compared to TO-220 resistors due to their larger package size, which enables better heat dissipation and allows for higher power ratings. The robust construction of TO-247 resistors reduces thermal stress and minimizes the risk of failure in high-temperature or high-current applications. Enhanced mechanical strength and improved electrical insulation in TO-247 packages contribute to their superior long-term performance in demanding electronic circuits.
Choosing Between TO-220 and TO-247 Resistors
TO-220 resistors offer compact size with moderate power dissipation, typically up to 2-3 watts, ideal for space-constrained circuits and moderate thermal requirements. TO-247 resistors provide higher power handling capabilities, up to 30-40 watts, thanks to their larger surface area and improved heat dissipation, making them suitable for high-power applications or environments with demanding thermal management. Selecting between TO-220 and TO-247 resistors depends primarily on the required power rating, thermal resistance specifications, and available PCB space for efficient heat sinking.
TO-220 resistor vs TO-247 resistor Infographic
