Description
- Switching Circuits: To turn loads like LEDs, buzzers, or relays ON/OFF.
- Signal Amplification: To strengthen weak electronic signals.
- Voltage Regulators: In circuits that control and stabilize voltage.
- Automotive Electronics: In vehicle electronic control units (as it is AEC-Q101 qualified).
A Short Example: High-Side Switch
Suppose you want to turn a 12V LED strip ON or OFF using a microcontroller (like an Arduino). Since this is a PNP transistor, it is used as a “High-Side” switch (meaning it sits between the positive power supply and the load).
How to connect it:
- Emitter (Pin 2): Connect this directly to the +12V power supply.
- Collector (Pin 3): Connect this to the positive terminal of the LED strip. (The negative end of the LED goes to Ground).
- Base (Pin 1): Connect this through a 1k\Omega resistor to your control signal or switch.
How it works:
- When the Base is LOW (0V): The transistor turns ON, allowing current to flow to the LED.
- When the Base is HIGH (Voltage): The transistor stays OFF, and the LED remains dark
