©2001 Fairchild Semiconductor Corporation

November 2001

Rev. A, November 2001

IRF840B/IRFS840B

500V N-Channel MOSFET

General Description

These N-Channel enhancement mode power field effect

transistors are produced using Fairchild’s proprietary,

planar, DMOS technology.

This advanced technology has been especially tailored to

minimize on-state resistance, provide superior switching

performance, and withstand high energy pulse in the

avalanche and commutation mode. These devices are well

suited for high efficiency switch mode power supplies,

power factor correction and electronic lamp ballasts based

on half bridge.

Features

• Low gate charge ( typical 41 nC)

• Low Crss ( typical 35 pF)

• Fast switching

• 100% avalanche tested

• Improved dv/dt capability

* Drain current limited by maximum junction temperature.

Thermal Characteristics

Symbol

Parameter

IRF840B

IRFS840B

Units

Drain-Source Voltage

500

V

Drain Current

8.0

8.0

A

5.1

5.1

A

Drain Current

- Pulsed

(Note 1)

32

32

A

Gate-Source Voltage

± 30

V

Single Pulsed Avalanche Energy

(Note 2)

320

mJ

Avalanche Current

(Note 1)

8.0

A

Repetitive Avalanche Energy

(Note 1)

13.4

mJ

dv/dt

Peak Diode Recovery dv/dt

(Note 3)

3.5

V/ns

134

44

W

- Derate above 25°C

1.08

0.35

W/°C

Operating and Storage Temperature Range

-55 to +150

°C

Maximum lead temperature for soldering purposes,

1/8" from case for 5 seconds

300

°C

Symbol

Parameter

IRF840B

IRFS840B

Units

Thermal Resistance, Junction-to-Case Max.

0.93

2.86

°C/W

Thermal Resistance, Case-to-Sink Typ.

0.5

--

°C/W

Thermal Resistance, Junction-to-Ambient Max.

62.5

62.5

°C/W

TO-220

IRF Series

G

S

D

S

D

G

TO-220F

IRFS Series

G

S

D