The 2TY is the marking of S8550 PNP SMD transistor. It is a BJT SOT 23 package tiny electronic component. In this article I’m sharing the information’s of 2TY SMD transistor Pinout, Equivalent replacement and its specification for quick reference.
What is the 2TY (S8550) SMD Transistor?
The 2TY is also known as S8550 PNP transistor and It is comes in SOT 23 packaging. This transistors are using for switching and low power handling applications like audio stage, LED circuits and low power switching circuits.
Its collector emitter voltage is about -25V and maximum collector current it can handle is about 500MA in SMD version. This transistor has high gain value so it can amplify small signal efficiently.
2TY (S8550) SMD Transistor Pinout Configuration
Pin Configuration
| Pin Number | Pin Name |
|---|---|
| 1 | Base (B) |
| 2 | Emitter (E) |
| 3 | Collector (C) |
2TY (S8550) Pin Identification and Package Details
Hold the transistor as flat and its numbering is facing you. count the pins from bottom left to right and top. The Left pin is Pin 1 next pion is 2 and the top pin is 3. To identify the pinout of this tiny component is Pin 1 is Base pin 2 is emitter and pin 3 is collector.
Key Specifications of the Transistor
- Type is PNP
- SOT023 Packaging.
- Collector-Emitter voltage is -25V
- Collector Base voltage is -40V
- Collector current is 500MA
- Maximum Power dissipation is 300mW
- DC current gain is 200 to 350 hfe
Complementary Pair
The SMD transistor marked with J3Y (S8050)is the NPN complementary transistor for 2TY.
How the Transistor Works
This is a BJT transistor so, it Turn ON if the base of the transistor get lower voltage than the emitter voltage. When it ON the current flow from Emitter to collector. The transistor turns OFF when the Emitter voltage and Base voltage is equal. This is only applicable for PNP type transistor Not for NPN Transistor.
Recommended Equivalent and Replacement Transistors
| Transistor | Marking Code | Type | Vce | Ic | Package |
|---|---|---|---|---|---|
| S8550 | 2TY / Y2 | PNP | -25V | -500mA to -700mA | SOT-23 |
| S9012 | 2T1 variants | PNP | -25V | -500mA | SOT-23 |
| BC807 | 5A / 5B variants | PNP | -45V | -500mA | SOT-23 |
| BC857 | 3F variants | PNP | -45V | -100mA | SOT-23 |
| MMBT3906 | 2A variants | PNP | -40V | -200mA | SOT-23 |
| 2N3906 | No SMD marking | PNP | -40V | -200mA | TO-92 |
| 2SA733 (A733) | A733 | PNP | -50V | -150mA | TO-92 |
Testing the 2TY (S8550) Transistor Using a Multimeter
- Set the multimeter to diode mode.
- Place the black probe of multimeter in base and Red on Emitter, the transistor is OK it shows value between 0.5 to 0.8V. Reverse the probe shows open loop.
- Place probes in one Emitter and one in collector if it shows open loop the transistor is good other wise it shorted.
Common Applications
- Used in LED strip lights to control LED’s.
- In battery powered circuits controlling the battery charging and relay control.
- Amplifying the weak signal so it is suitable for signal amplification.
- In sensor circuit it act like a switching control.
