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Shipping Methods TO220 - TO3P Transistor
TO-220 & TO-3P Package Overview
TO-220 Package
TO-220 (Transistor Outline 220) is a through-hole power semiconductor package widely used for power transistors, thyristors, and three-terminal voltage regulators. It is available in bothisolated types (TO-220F, TO-220I) andnon-isolated types. The TO-220F offers full plastic encapsulation with 2500 VAC isolation withstand voltage, while the TO-220I features an internal isolation barrier with superior thermal performance.
Key Variants
- TO-220AB: Standard non-isolated, 3-pin, metal tab connected to leads.
- TO-220AC: 2-pin, single-chip device for unidirectional conduction.
- TO-220F: Fully isolated, plastic-encapsulated tab, 2500 VAC isolation.
- TO-220I: Internal isolation barrier, better thermal performance than TO-220F.
Thermal & Power Characteristics
- θJA: ~60 °C/W; θJC: ~3 °C/W
- Power dissipation: ~65 W under ideal heatsinking (TC = 25 °C)
- Typical body size: 9.2 mm × 9.9 mm (excluding tab); 2.54 mm pin pitch
TO-3P Package
TO-3P (Transistor Outline 3-Pin Plastic) is a robust industry-standard power semiconductor package known for its excellent thermal and power-handling capabilities, succeeding the older metal-cased TO-3. It features a sturdy rectangular plastic body with a large integral metal tab for heatsinking, typically with three leads on a 5.08 mm pitch.
Thermal & Power Characteristics
- θJC: as low as 0.42–0.67 °C/W
- Power dissipation: up to 300 W+ under proper heatsinking
- Typical dimensions: 15.5 mm × 20.0 mm × 4.5 mm
- Weight: ~5.5 g
Applications
- AC/DC motor drives, robotics, and servo controls
- Switched-mode and resonant-mode power supplies
- DC-DC converters, battery chargers, UPS systems
- Welding equipment, induction heating, power tools
- High-fidelity audio amplifiers and solar PV inverters
Comparison
| Parameter | TO-220 | TO-3P |
|---|---|---|
| Body Size | ~9.2 × 9.9 mm | ~15.5 × 20.0 mm |
| Pin Pitch | 2.54 mm | 5.08 mm |
| Typical θJC | ~3 °C/W | 0.42–0.67 °C/W |
| Max Power Dissipation | ~65 W | 300 W+ |
| Current Range | Up to 120 A (medium voltage) | 10 A+ (medium/high voltage) |
| Tab Type | Thin metal / plastic-encapsulated | Large integral metal tab |
| Typical Applications | Regulators, small power switches, fast chargers | Motor drives, power supplies, audio amplifiers |
For medium-power applications below 50 A, TO-220 is the more economical choice. For currents above 50 A, TO-3P is preferred due to its larger footprint and superior thermal performance. The TO-3P and TO-247 are functionally equivalent with interchangeable bare chips; the TO-3P has a slightly larger footprint and marginally better thermal performance.
