C550 Bipolar Transistors – NPN
The BC550 is a low-noise, general-purpose NPN epitaxial silicon transistor in a TO-92 package. It is optimized for amplifier and switching applications where low noise and moderate voltage handling (up to 45 V collector–emitter) are required
Features
- Switching and Amplifier functionality
- High‑Voltage capability (VCEO up to 45 V)
- Low‑Noise performance (noise figure down to 1.4 dB)
- Complementary to BC556, BC557, BC558, BC559, and BC560 series
- Pb‑Free Device, RoHS‑compliant
Specifications
Absolute Maximum Ratings (TJ = 25 °C)
| Parameter |
Symbol |
Value |
Unit |
| Collector–Base Voltage |
VCBO
|
50 |
V |
| Collector–Emitter Voltage |
VCEO
|
45 |
V |
| Emitter–Base Voltage |
VEBO
|
5 |
V |
| Collector Current (DC) |
IC
|
100 |
mA |
| Collector Power Dissipation |
PC
|
500 |
mW |
| Junction Temperature |
TJ
|
150 |
°C |
| Storage Temperature Range |
TSTG
|
–65 to +150 |
°C |
Electrical Characteristics (TC = 25 °C)
| Parameter |
Symbol |
Test Conditions |
Min |
Typ |
Max |
Unit |
| Collector Cut‑off Current |
ICBO
|
VCB = 30 V, IE = 0 |
— |
— |
15 |
nA |
| DC Current Gain |
hFE
|
VCE = 5 V, IC = 2 mA |
110 |
— |
800 |
— |
| VCE(sat) (low‑current) |
— |
IC = 10 mA, IB = 0.5 mA |
— |
90 |
250 |
mV |
| VCE(sat) (high‑current) |
— |
IC = 100 mA, IB = 5 mA |
— |
250 |
600 |
mV |
| VBE(on)
|
— |
VCE = 5 V, IC = 2 mA |
580 |
660 |
700 |
mV |
| VBE(on) (at 10 mA) |
— |
VCE = 5 V, IC = 10 mA |
— |
720 |
— |
mV |
| VBE(sat)
|
— |
IC = 10 mA, IB = 0.5 mA |
— |
700 |
— |
mV |
| VBE(sat) (high‑current) |
— |
IC = 100 mA, IB = 5 mA |
— |
900 |
— |
mV |
| Current Gain Bandwidth |
fT
|
VCE = 5 V, IC = 10 mA, f = 100 MHz |
— |
300 |
— |
MHz |
| Output Capacitance |
Cob
|
VCB = 10 V, IE = 0, f = 1 MHz |
— |
3.5 |
6.0 |
pF |
| Input Capacitance |
Cib
|
VEB = 0.5 V, IC = 0, f = 1 MHz |
— |
9 |
— |
pF |
| Noise Figure (BC550) |
N.F. |
VCE = 5 V, IC = 200 µA, f = 1 kHz, RG = 2 kΩ |
1.4 |
— |
3.0 |
dB |
|
Applications
-
Audio Amplifiers and Preamplifiers: Provides clean, low-noise signal amplification.
-
Signal Amplification: Ideal for sensors, detectors, and other sensitive devices.
-
Switching Circuits: Used in digital logic and control systems.
-
Oscillator Circuits: Suitable for generating signals in various frequency ranges.
