What is K3878? – 900V, 9A, N-channel MOSFET

This post explains for the semiconductor 2SK3878.

What is K3878?

It is a specific electronic component, which is a N-channel MOSFET transistor commonly used in electronic circuits. It has a maximum voltage rating of 900 volts and a maximum current rating of 9 amperes.

This is one of the types of MOSFETs and is a kind of transistor.

The Part Number is K3878.

The function of this semiconductor is 900V, 9A, N-Channel MOS Field Effect Transistor.

Manufacturer: Toshiba

Images :

K3878 Datasheet

Pinout: 1. Gate  2. Dreain ( Heatsink )  3. Source

Absolute Maximum Ratings (Ta = 25°C)

1. Drain to source voltage: VDSS = 900 V
2. Gate to source voltage: VGSS = 900 V
3. Drain current: ID = 9 A
4. Drain power dissipation : PD = 150 W
5. Single pulse avalanche energy : Eas = 778 mJ
6. Avalanche curren : Iar = 9 A
7. Repetitive avalanche energy : Ear = 15 mJ
8. Channel temperature: Tch = 150 °C
9. Storage temperature: Tstg = -55 to +150 °C

1 page
K3878 image


K3878 is 900V, 9A, Silicon N-Channel MOS Type Field Effect Transistor. It is commonly used in power supply circuits, audio amplifiers, and other electronic applications that require switching or amplification of high voltages and currents.

Advantages Vs Disadvantages


1. High Voltage Rating: High maximum voltage rating of 900 volts, which makes it suitable for use in circuits that require high voltage handling.

2. Low On-Resistance: Low on-resistance, which means that it can handle high currents with minimal power loss.

3. Fast Switching Speed: Fast switching speed, which makes it suitable for use in circuits that require fast switching times.


1. Sensitivity to Static Electricity: Sensitive to static electricity, and improper handling can damage the device.

2. Limited Current Rating: The K3878 has a maximum current rating of 9 amperes, which limits its use in high-current applications.

3. Limited Availability: It is not as widely available as other MOSFET transistors, which can make it difficult to source for some applications.


1. Low drain-source ON-resistance: RDS (ON) = 1.0 Ω (typ.)

2. High forward transfer admittance: ⎪Yfs⎪ = 7.0 S (typ.)

3. Low leakage current: IDSS = 100 μA (max) (VDS = 720 V)

4. Enhancement model: Vth = 2.0 to 4.0 V (VDS = 10 V, ID = 1 mA)


2 page


: Switching Regulator

K3878 Datasheet