This post explains for the transistor.

Part Number: 2N2222A

Function: Silicon Planar Epitaxial NPN Transistor

Package: TO-18

Manufacturer: STMicroelectronics

Image

Description

This is 40V, 800mA, NPN Transistor.

The 2N2219A and 2N2222A are silicon Planar Epitaxial NPN transistors in Jedec TO-39 (for 2N2219A) and in Jedec TO-18 (for 2N2222A) metal case. They are designed for high speed switching application at collector current up to 500mA, and feature useful current gain over a wide range of collector current, low leakage currents and low saturation voltage.

2N2222A Pinout

 

ABSOLUTE MAXIMUM RATINGS

1. Collector-Base Voltage (IE= 0) : VCBO = 75 V

2. Collector-Emitter Voltage (IB= 0) : VCEO = 40 V

3. Emitter-Base Voltage (IC= 0) : VEBO = 6 V

4. Collector Current : IC = 0.6 A

5. Collector Peak Current (tp< 5 ms) : ICM = 0.8 A

 

Reference Site

1. https://en.wikipedia.org/wiki/2N2222

2. https://www.onsemi.com/products/discrete-power-modules/general-purpose-and-low-vcesat-transistors

 

2N2222A Datasheet

 

Other data sheets are available within the file:  2N2219A, 2N2222

Related articles across the web

• Blog Post: What to consider when designing an automotive power supply
• Applying MOSFETs to Today’s Power-Switching Designs