KSP2222A — 40V 600mA High-Current NPN BJT (Modern TO-92 2N2222A)

Overview

The KSP2222A is a high-current, high-speed general-purpose NPN bipolar junction transistor manufactured by onsemi (originally Fairchild Semiconductor). Housed in an industry-standard TO-92 through-hole plastic package with Emitter - Base - Collector (E-B-C) pinout, it represents the modern commercial manufacturing designation for the world-famous 2N2222A / PN2222A.

Delivering a collector-emitter breakdown voltage ( $V_{CEO}$ ) of $40\text{V}$ , a maximum continuous collector current of $600\text{ mA}$ ( $1.0\text{A}$ pulsed), and a rapid transition frequency ( $f_T$ ) of $300\text{ MHz}$ , the KSP2222A provides high current-gain bandwidth and low saturation resistance. It is standard equipment for driving $5\text{V}$ and $12\text{V}$ relays, DC motors, solenoids, high-current LED strings, audio output stages, and RF oscillator circuits.

Quick reference


Transistor Type	High-Current General-Purpose NPN BJT
Package	TO-92 (3-pin through-hole)
Collector-Emitter Voltage ( $V_{CEO}$ )	$40\text{ V}$ max
Collector-Base Voltage ( $V_{CBO}$ )	$75\text{ V}$ max
Continuous Collector Current ( $I_C$ )	$600\text{ mA}$ max ( $1.0\text{ A}$ pulsed)
DC Current Gain ( $h_{FE}$ )	$100$ to $300$ ( $I_C = 150\text{mA}, V_{CE} = 10\text{V}$ ) / $> 40$ at $500\text{mA}$
Transition Frequency ( $f_T$ )	$300\text{ MHz}$ min
Total Power Dissipation ( $P_D$ )	$625\text{ mW}$ ( $T_A = 25^\circ\text{C}$ )
Complementary PNP Pair	KSP2907A (40V PNP)
Pinout Standard	`E - B - C` (Pin 1: Emitter, Pin 2: Base, Pin 3: Collector)

Pinout (TO-92 Package - E-B-C Standard)

Looking at the flat front face with leads pointing downward:

text

        ┌──────────┐
        │  TO-92   │
        │ KSP2222A │
        └─┬───┬───┬┘
          1   2   3
          E   B   C

Pin	Name	Type	Description
1	`EMITTER`	Emitter Terminal	Emitter (Connect to ground or common return / $0\text{ V}$ )
2	`BASE`	Base Terminal	Base control input (Driven with current via series resistor)
3	`COLLECTOR`	Collector Terminal	Collector output (Connected to switched DC load or supply rail)

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Collector-Emitter Breakdown	$V_{(BR)CEO}$	40	—	—	V	$I_C = 10\text{mA}, I_B = 0$
Collector-Base Breakdown	$V_{(BR)CBO}$	75	—	—	V	$I_C = 10\ \mu\text{A}, I_E = 0$
Emitter-Base Breakdown	$V_{(BR)EBO}$	6.0	—	—	V	$I_E = 10\ \mu\text{A}, I_C = 0$
DC Current Gain ( $h_{FE}$ )	$h_{FE}$	35	—	—	—	$I_C = 0.1\text{mA}, V_{CE} = 10\text{V}$
DC Current Gain ( $h_{FE}$ )	$h_{FE}$	100	—	300	—	$I_C = 150\text{mA}, V_{CE} = 10\text{V}$
DC Current Gain ( $h_{FE}$ )	$h_{FE}$	40	—	—	—	$I_C = 500\text{mA}, V_{CE} = 10\text{V}$
Collector Saturation Voltage	$V_{CE(sat)}$	—	—	0.30	V	$I_C = 150\text{mA}, I_B = 15\text{mA}$
Collector Saturation Voltage	$V_{CE(sat)}$	—	—	1.00	V	$I_C = 500\text{mA}, I_B = 50\text{mA}$
Output Capacitance	$C_{obo}$	—	—	8.0	pF	$V_{CB} = 10\text{V}, f = 1.0\text{MHz}$

Part Number Equivalencies

Part Number	Package	Notes
2N2222A	TO-18 (Metal Can)	Historic JEDEC metal hermetic package
PN2222A	TO-92 (Plastic)	Traditional plastic through-hole package
KSP2222A	TO-92 (Plastic)	Fairchild / onsemi automated high-volume production part number
MMBT2222A	SOT-23 (SMD)	Surface-mount equivalent

Common mistakes

Treating as a logic-level MOSFET: The KSP2222A is a bipolar junction transistor requiring a continuous base current ( $I_B = I_C / 10$ ) to remain in full saturation. Omitting the base current-limiting resistor or providing insufficient drive current will prevent the transistor from fully turning on.

Notes

Suffix Guide: BU indicates bulk packaging; TA indicates ammo tape packaging; TFR indicates tape and reel.