4128D PDF Datasheet – 200V, 5A, NPN Transistor

Part Number: 4128D

Function: 200V, 5A, NPN Transistor

Package: TO-126 Type

Manufacturer: Unisonic Technologies

Images:4128D pdf pinout


The UTC 4128D is a middling voltage NPN power transistor. it uses UTC’s advanced technology to provide customers with high switching speed and high reliability, etc. The UTC 4128D is suitable for commonly power amplifier circuit, electronic ballasts and energy-saving light etc.


1. High switching speed

2.  High reliability


1. Bipolar Junction: NPN transistors are bipolar junction transistors (BJT), meaning they have a structure consisting of three regions of alternating P-type and N-type semiconductors.

2. Current Amplification: NPN transistors are designed to amplify electrical current, and can be used in a wide range of electronic applications such as amplifiers, switches, and oscillators.

3. Forward Biased: In order to operate, the base-emitter junction of an NPN transistor must be forward biased, meaning that the base must be connected to a positive voltage relative to the emitter.

4. High Input Impedance: NPN transistors have a high input impedance, which means that they are less likely to draw current from the input source, and are therefore less likely to cause a drop in voltage across the source.

5. Inverted Output: NPN transistors are known for producing an inverted output relative to their input. That is, if the input signal is high, the output signal will be low, and vice versa. This behavior is due to the way the transistor is designed and is an important characteristic for many electronic applications.

4128D datasheet transistor

Absolute maximum ratings ( Ta=25°C )

1. Collector to Emitter Voltage: Vceo = 200 V

2. Emitter to Base Voltage: Vebo = 7 V

3. Collector Current: Ic = 5 A

4. Collector Dissipation : Pc = 40 W

5. Junction Temperature: Tj = 150°C

6. Storage Temperature: Tsg = -55 ~ +150°C


4128D PDF Datasheet