1. Overview & Mechanical Data

️· Type: NPN Transistors
️· Case: TO-39
️· Pinout:
- Pin 1: Emitter
- Pin 2: Base
- Case: Collector
️· Mechanical Dimensions: (in mm)
- A: 6.25
- B: 13.59
- C: 9.24
- D: 8.24
- E: 0.78
- F: 1.05
- G: 0.42
- H: 45° (angle)
- L: 4.1

2. Electrical Characteristics (Absolute Maximum Ratings - NOT typically used for design, but represent limits)

*The datasheet does not include absolute maximum ratings directly.*

3. Electrical Characteristics (Typical/Minimum/Maximum Values - For design and operation)

I'm going to organize this into sections based on what the characteristics measure. Note: values often differ between the 2N2218A and the 2N2219A.

a) DC Characteristics

️· hFE (DC Current Gain): This is a large range and varies significantly with collector current (Ic). A simplified summary is below, but *refer to the datasheet tables for specific conditions and the ranges*.
- 2N2218A:
■ Ic = 1mA, Vce = 10V: hFE = 30 - 75
■ Ic = 20mA, Vce = 20V: hFE = 25 - 35
■ Ic = 100mA, Vce = 20V: hFE = 20 - 25
■ Ic = 150mA, Vce = 20V: hFE = 30 - 200 (wide range!)
- 2N2219A:
■ Ic = 1mA, Vce = 10V: hFE = 30-50
■ Ic = 20mA, Vce = 20V: hFE = 30-40
■ Ic = 150mA, Vce = 20V: hFE = 50 - 200 (wide range!)
️· VCE(sat) (Collector-Emitter Saturation Voltage): This is the voltage between the collector and emitter when the transistor is fully on.
- 2N2218A: Ic = 150mA, Ib = 15mA: Vce(sat) = 0.3V
- 2N2219A: Ic = 150mA, Ib = 15mA: Vce(sat) = 0.3V
️· VBE(sat) (Base-Emitter Saturation Voltage): This is the voltage between the base and emitter when the transistor is fully on.
- 2N2218A: Ic = 150mA, Ib = 15mA: Vbe(sat) = 1.2V
- 2N2219A: Ic = 150mA, Ib = 15mA: Vbe(sat) = 1.2V
️· rb,CC (Feedback Time Constant):
- 2N2218A: Ic = 20mA, Vce = 20V: rb,CC = 150ps
- 2N2219A: data not provided.

b) Switching Characteristics (Speed - Important for high-frequency applications)

️· td (Delay Time): The time delay from when the base current starts to flow to when the collector current begins to change.
- 2N2218A: Ic = 150mA, Ib = 15mA, VCC = 30V: td = 10ns
- 2N2219A: data not provided.
️· tr (Rise Time): The time it takes for the collector current to rise from 10% to 90% of its final value.
- 2N2218A: Ic = 150mA, Ib = 15mA, VCC = 30V: tr = 25ns
- 2N2219A: data not provided.
️· ts (Storage Time): The time the base current must be present for the transistor to switch on.
- 2N2218A: Ic = 150mA, Ib1 = -Ib2 = 15mA, VCC = 30V: ts = 225ns
- 2N2219A: data not provided.
️· tf (Fall Time): The time it takes for the collector current to fall from 90% to 10% of its initial value.
- 2N2218A: Ic = 150mA, Ib1 = -Ib2 = 15mA, VCC = 30V: tf = 60ns
- 2N2219A: data not provided.
️· fT (Transition Frequency): Frequency at which the current gain drops to 1.
- 2N2218A: Ic = 20mA, Vce = 20V: fT = 250MHz
- 2N2219A: Ic = 20mA, Vce = 20V: fT = 300MHz
️· hfe (Small Signal Current Gain): Similar to DC hFE, but measured with a small signal.
* 2N2218A: Ic = 1mA, Vce = 10V: hfe = 50
* 2N2219A: Ic = 1mA, Vce = 10V: hfe = 30

Important Considerations:

️· Pulse Conditions: The switching characteristics are measured under pulse conditions: tp < 300 µs, δ = 2%. This means they are measured with very short pulses and a small duty cycle (only a small percentage of time). These parameters may differ under continuous operation.