1. General Description

️· Type: NPN Silicon Transistor
️· Application: Designed for matched characteristics (DC Current Gain, Collector-Emitter Saturation Voltage, and Base-Emitter Saturation Voltage). This suggests it's intended for applications where consistent performance between transistors is important (e.g., differential amplifiers, matched pairs in switching circuits).
️· Package: Not explicitly stated in the provided excerpts.

2. Electrical Characteristics (Absolute Maximum Ratings & DC/AC Characteristics)

*Note: Absolute maximum ratings are stress levels and operation beyond them may cause permanent damage.*

️· Collector-Base Voltage (Vcb): 60V
️· Collector-Emitter Voltage (Vce): 30V
️· Emitter-Base Voltage (Veb): 5V
️· Collector Current (Ic): 100mA
️· Power Dissipation (Pd): 200mW
️· Operating Temperature Range: -25°C to +125°C
️· DC Current Gain (hFE): Matched at Ic = 10mA, Vce = 1.0V. Typical matched tolerances of 1% with a maximum of 2%. This is a critical specification.
️· Collector-Emitter Saturation Voltage (Vce(sat)): Not explicitly listed, but it's a key parameter being matched.
️· Base-Emitter Saturation Voltage (Vbe(sat)): Similar to Vce(sat), it's a matched parameter but not specifically stated.
️· Input Impedance (hie): 1.0 to 10 kΩ
️· Voltage Feedback Ratio (hre): 0.5 x 10^-4
️· Current Gain-Bandwidth Product (fT): 300 MHz
️· Noise Figure (NF): Up to 5.0 dB (at specified conditions).
️· Switching Characteristics: td (Delay Time) up to 35ns; tr (Rise Time) up to 35ns, ts (Storage Time) up to 200ns, tf (Fall Time) up to 50ns.
️· Output Capacitance (Cobo): Up to 4.0pF
️· Input Capacitance (Cibo): Up to 8.0pF

3. Marking and Packaging

️· Marking Code:
- `K4A`: Denotes product type.
- `YM`: Date code.
️· Date Code Breakdown:
- `N` (Year): 2002
- `P`: 2003
- `R`: 2004
- `S`: 2005
- `T`: 2006
- `U`: 2007
- `V`: 2008
- Example: `N` followed by a code for the Month (Jan = 1, Feb = 2, etc.)

4. Key Figures/Graphs (Descriptions - I can't *show* them, but I'm describing what they illustrate):

️· Figure 1 (Max Power Dissipation vs. Ambient Temperature): Shows how the maximum power that can be dissipated by the transistor decreases as the ambient temperature increases.
️· Figure 3 (Typical DC Current Gain vs. Collector Current): Shows the relationship between the DC current gain (hFE) and the collector current (Ic). It provides a typical curve showing that hFE generally increases with Ic.
️· Figure 4 (Typical Collector-Emitter Saturation Voltage vs. Collector Current): Illustrates how the collector-emitter saturation voltage (Vce(sat)) changes with the collector current (Ic). Shows a decrease in Vce(sat) as Ic increases, eventually leveling off.
️· Figure 5 (Typical Base-Emitter Saturation Voltage vs. Collector Current): Illustrates the relationship between base-emitter saturation voltage (Vbe(sat)) and collector current.
️· Figure 2 (Input and Output Capacitance vs. Collector-Base Voltage): Provides information on the input (Cibo) and output (Cobo) capacitances as a function of the collector-base voltage.
️· Figure (Switching Characteristics): Demonstrates the transistor's switching speed through various timing parameters (td, tr, ts, tf) under specific test conditions.

Important Notes

️· Matched Characteristics: The primary selling point of this transistor is its matched DC characteristics (hFE, Vce(sat), Vbe(sat)). This means that transistors selected for use in critical applications can be matched to have similar gains and saturation voltages.
️· Datasheet Limitations: The provided information is only a subset of a complete datasheet. A full datasheet would contain more detailed specifications, graphs, and test conditions.
️· Conditions: All electrical characteristics are specified at particular test conditions (e.g., temperature, voltage levels). It's vital to consider these conditions when interpreting the data.