Home > Integrated Circuits ICs > Analog Linear ICs > SS8050

SS8050

NPN BJT, 25V 1.5A, TO-92, audio/driver transistor

44000

Effective Inventory

Go to Inquiry

Image for reference only

Manufacturer Part：

SS8050

Package：

TO-92-3 (4.83 x 4.76 x 4.19mm, 2.54mm pitch, through-hole)

Brand：

Product Categories：

Analog Linear ICs, Integrated Circuits ICs

Other recommendations you may be interested in.

SII9396SCNUC-BAR

IS43TR16256BL-125KBLI

Description

Product Overview

The SS8050 from onsemi is a medium-power NPN transistor with 25V collector-emitter voltage, 1.5A collector current, and 1W power dissipation in a TO-92 package — widely used in consumer electronics for driver and output stages.

Key Specifications

Type	NPN Bipolar Junction Transistor
Collector-Emitter Voltage (VCEO)	25V
Collector-Base Voltage (VCBO)	40V
Emitter-Base Voltage (VEBO)	6V
Collector Current (IC)	1.5A continuous
DC Current Gain (hFE)	85-300 @ IC=100mA, VCE=1V (Grade B/C/D)
VCE(sat)	0.5V max @ IC=800mA, IB=80mA
VBE(sat)	1.2V max @ IC=800mA, IB=80mA
Transition Frequency (fT)	100MHz minimum
Output Capacitance (Cob)	9pF typical
Power Dissipation	1W @ TA=25°C (TO-92)
Operating Temperature	-65°C to +150°C
Package	TO-92-3 (4.83 x 4.76mm)

Features

1.5A collector current in compact TO-92
Complementary PNP: SS8550
Class B push-pull amplifier capable
Three hFE grades: B (85-160), C (120-200), D (160-300)
Low saturation voltage: 0.5V @ 800mA

Applications

Audio output stage (class B push-pull)
LED driver
Low-voltage switching
Motor driver (small DC motors)
Signal amplification

Product Introduction:SS8050 Product Introduction

The SS8050 from onsemi (formerly Fairchild) is a medium-power NPN transistor in a TO-92 package, offering 1.5A collector current — significantly higher than typical small-signal transistors like BC547 (100mA) or 2N3904 (200mA). The 25V VCEO limits it to low-voltage applications (3.3V to 12V systems), but within that range, the 1.5A capability makes it suitable for driving LEDs, small motors, and audio output stages. The complementary PNP device is the SS8550, enabling push-pull amplifier configurations. The three hFE grades (B, C, D) allow designers to select the gain range appropriate for their application: Grade B for switching (lower gain, faster), Grade D for amplification (higher gain, more consistent). The 100MHz fT is lower than the 2N2222A’s 300MHz but sufficient for audio and moderate-frequency switching. The 1W power dissipation in TO-92 requires careful thermal management; at IC=500mA and VCE=1V, dissipation is 500mW, which is manageable. At IC=1A and VCE=2V, dissipation is 2W, exceeding the TO-92 rating.

Working Principle:SS8050 Working Principle

The SS8050 is a standard NPN bipolar junction transistor. When base current IB flows into the base terminal, collector current IC = hFE × IB flows from collector to emitter. For switching, the transistor is driven into saturation by providing IB ≥ IC/hFE(min). For a 500mA load with Grade C (hFE min = 120): IB ≥ 500mA/120 = 4.2mA; with 2× overdrive, IB = 8.4mA. Base resistor: RB = (Vdrive − VBE) / IB = (3.3V − 0.7V) / 8.4mA ≈ 310Ω. In saturation, VCE(sat) ≤ 0.5V at IC=800mA. For audio amplification in Class B push-pull, two SS8050 (NPN) and SS8550 (PNP) transistors are connected in complementary push-pull: each conducts on alternate half-cycles, driving the speaker through a coupling capacitor. The 1.5A rating and low VCE(sat) make the SS8050 well-suited for this application at supply voltages up to 12V.

Pin Description:SS8050 Pin Definition and Functions

Pin	Name	Type	Description
1	Emitter	Output	Emitter terminal. In common-emitter configuration, this pin connects to ground (for NPN). Maximum continuous emitter current is 1.5A. The emitter is the reference terminal for both base-emitter voltage (VBE ≈ 0.7V) and collector-emitter voltage ratings.
2	Base	Input	Base terminal controls collector current flow. Base current IB drives the transistor into active or saturation region. DC current gain hFE ranges from 85 to 300 depending on grade. Drive IB > IC/hFE(min) to ensure saturation. Maximum base current is 500mA (pulsed).
3	Collector	Power Output	Collector terminal connects to the load through the power supply. Rated for 25V VCEO and 1.5A continuous collector current. Power dissipation 1W at TA=25°C or 2.5W at TC=25°C. Minimum VCE(sat) is 0.5V at IC=800mA, IB=80mA for efficient switching.

SS8050 pin assignment (TO-92-3, flat face toward you, pins down): Pin 1 (left) = Emitter, Pin 2 (center) = Base, Pin 3 (right) = Collector. WARNING: TO-92 pinout varies by manufacturer. Some SS8050 variants use ECB (Emitter-Collector-Base) order. Always verify pinout with the specific manufacturer’s datasheet. Complementary PNP: SS8550 (25V/-1.5A). SMD equivalent: S8050 (SOT-23) for compact PCB layouts.

Application Scenarios:In which products and applications isSS8050 used

LED Driver: MCU GPIO → 470Ω → base; collector to LED array (up to 1A); emitter GND; switches 12V LED strips
Push-Pull Audio: SS8050 (NPN) + SS8550 (PNP) in complementary push-pull; 9V supply; 8Ω speaker via 470µF coupling cap; ~500mW output
Motor Driver: 6V DC motor (500mA); base from MCU PWM through 330Ω; collector to motor; emitter GND; flyback diode
Relay Driver: 5V relay coil (100mA); base from MCU through 1kΩ; collector to relay; emitter GND; flyback diode

Alternative Models:What chips are recommended as replacements for SS8050

Model	Manufacturer	Key Difference	Package	Specs
SS8550	onsemi	PNP complementary, same specs, TO-92	–	–
S8050 (SOT-23)	Various	SMD version, 350mW dissipation, SOT-23	–	–
2N2222A	onsemi	40V/600mA, higher voltage, TO-92	–	–
BC547B	Various	45V/100mA, lower current, low noise, TO-92	–	–
S9013	Various	30V/500mA, similar range, TO-92	–	–

SS8050 is an NPN 25V/1.5A general-purpose transistor in TO-92 from multiple manufacturers. The complementary PNP is SS8550 (-25V/-1.5A). The S8050 is the SMD equivalent in SOT-23 with lower 500mA rating. The 2N5551 provides higher 160V VCEO at 600mA for high-voltage switching. The BC547B offers lower current (100mA) with higher gain (200-450 hFE) for small-signal amplification. The MPS2222A from onsemi provides 75V/600mA in SOT-23 for surface-mount. For Darlington gain, TIP122 offers 1000x hFE at 5A in TO-220.