The 2N3906 PNP Transistor is a widely used PNP bipolar junction transistor (BJT) designed for low-power switching and amplification.
 
Key Features
Type: PNP transistor
Package: TO-92 (small plastic package)
Low power consumption
Fast switching capability
Commonly used in signal processing circuits
 
Electrical Specifications
Collector-Emitter Voltage (Vce): −40V
Collector-Base Voltage (Vcb): −40V
Emitter-Base Voltage (Veb): −5V
Collector Current (Ic): −200mA (max)
Power Dissipation: 625mW
Gain (hFE): 100 – 300 (typical)
 
Pin Configuration (TO-92)
When the flat side faces you:
Emitter (E)
Base (B)
Collector (C)
 
Working Principle
Being a PNP transistor:
It turns ON when the base is LOW relative to the emitter.
Current flows from Emitter → Collector.
Used where negative switching is required.
 
Common Applications
Signal amplification
Switching circuits
Audio circuits
Complementary pair with 2N3904 NPN Transistor
Small load control (LEDs, relays)
 
Simple Example
If you want to control an LED:
Connect Emitter → VCC
Connect Collector → LED → Resistor → GND
Apply LOW signal to base → transistor turns ON → LED lights