SS8050 NPN Power Transistor
= PlasticEncapsulated MediumPower Switching and Amplification Transistor =
The SS8050 is a widely used NPN bipolar junction transistor (BJT) designed for generalpurpose switching and amplification applications . This mediumpower transistor is commonly available in both TO92 and SOT23 packages, making it suitable for throughhole and surfacemount designs .
Medium Power Handling - Supports up to 1.5A collector current for driving moderate loads
High Current Gain hFE range of 85400 for reliable amplification
Collector-Emitter Voltage (VCEO): 25V maximum
Collector-Base Voltage (VCBO): 40V maximum
Emitter-Base Voltage (VEBO): 5V maximum
Complementary PNP pair is the SS8550 transistor for push-pull configurations
Power dissipation varies by package: 300mW for SOT23, 1W for TO92
= Technical Specifications =
| Parameter | Value |
|---|
| Transistor Type | NPN |
| Collector Current (IC) | 1.5A maximum |
| Collector-Emitter Voltage (VCEO) | 25V maximum |
| Collector-Base Voltage (VCBO) | 40V maximum |
| Emitter-Base Voltage (VEBO) | 5V maximum |
| DC Current Gain (hFE) | 85 to 400 (varies by rank) |
| Transition Frequency (fT) | 100MHz minimum |
| Power Dissipation | 300mW (SOT23) / 1W (TO92) |
| Operating Temperature | -55°C to +150°C |
| Package Options | TO92, SOT23, SOT-89 |
= hFE Classification Ranks (TO-92 Package) =
| Rank | hFE Range |
|---|
| B | 85-160 |
| C | 120-200 |
| D | 160-300 |
| D3 | 300-400 |
For SOT23 package, hFE ranks are typically 120200, 200350, and 300400
Check the marking on the component for the specific gain rank
= Pin Configuration (TO-92 Package) =
When viewing the flat side with leads pointing downward, the pinout from left to right is:
| Pin | Function |
|---|
| 1 | Emitter (E) |
| 2 | Base (B) |
| 3 | Collector (C) |
Always verify pinout with the manufacturer's datasheet as variations may exist
= Key Features =
+High Collector Current - 1.5A for driving relays, motors, and LEDs
+Low Saturation Voltage - VCE(sat) of 0.5V at 800mA for efficient switching
+Fast Switching 100MHz transition frequency for highspeed applications
+Complementary PNP Pair Use with SS8550 for pushpull circuits
== Applications ==
- Audio amplifiers and signal amplification circuits
- Switching applications (relay drivers, LED drivers)
- Power management and voltage regulation circuits
- Logic level conversion and switching
- Sensor signal conditioning
Reliable and CostEffective A staple component for hobbyist and professional projects
ThroughHole and SMD Options Versatile package choices for different PCB designs
√ Direct substitutes include S8050, 2N3904, BC547, MPS650
| √ Complementary pair | SS8550 PNP transistor |
√ Widely available and well-documented
= Troubleshooting =
Transistor not switching:
- Verify base-emitter voltage is above 0.7V
- Check base resistor value (typically 1kΩ to 10kΩ)
- Ensure collector current does not exceed 1.5A
Excessive heat:
- Verify load current is below maximum rating
- Check for adequate heat dissipation (especially in SOT-23 package)
- Use higher gain rank for lower base drive requirements
