Fairchild FDD8451 service manual

May 2009

FDD8451 N-Channel PowerTrench

FDD8451
N-Channel PowerTrench

40V, 28A, 24m:

Features

 Max r

 Max r

 Low gate charge

 Fast Switching

 High performance trench technology for extremely low

r

DS(on)

 RoHS compliant

24m: at VGS= 10V, ID = 9A

DS(on)

30m: at VGS= 4.5V, ID = 7A

DS(on)

F

D

A

E

L

®

E

E

R

I

M

P

L

E

M

E

N

T

A

T

I

O

N

MOSFET

General Description

This N-Channel MOSFET has been designed specifically
to improve the overall efficiency of DC/DC converters using
either synchronous or conventional switching PWM
controllers. It has been optimized for low gate charge, fast
switching speed and extremely low r

Application

 DC/DC converter

 Backlight inverter

D

G

DS(on)

.

tm

®

MOSFET

S

MOSFET Maximum Ratings T

Symbol Parameter Ratings Units

V

DS

V

GS

I

D

E

AS

P

D

, T

T

J

STG

Drain to Source Voltage 40 V

Gate to Source Voltage ±20 V

Drain Current -Continuous@TC=25°C 28

-Pulsed

Single Pulse Avalanche Energy (Note 3)20 mJ

Power Dissipation 30 W

Operating and Storage Temperature -55 to 150 °C

= 25°C unless otherwise noted

C

=25°C 9

A

(Note 1a)

78

Thermal Characteristics

R

TJC

R

TJA

R

TJA

Thermal Resistance, Junction to Case 4.1 °C/W

Thermal Resistance, Junction to Ambient (Note 1a) 40 °C/W

Thermal Resistance, Junction to Ambient (Note 1b) 96 °C/W

Package Marking and Ordering Information

Device Marking Device Package Reel Size Tape Width Quantity

FDD8451 FDD8451 D-PAK(TO-252) 13’’ 12mm 2500 units

©2009 Fairchild Semiconductor Corporation
FDD8451 Rev. B2

www.fairchildsemi.com1

A -Continuous @T

FDD8451 N-Channel PowerTrench

Electrical Characteristics T

= 25°C unless otherwise noted

J

Symbol Parameter Test Conditions Min Typ Max Units

Off Characteristics

BV

'BV
'T

I

DSS

I

GSS

DSS

DSS

J

Drain to Source Breakdown Voltage ID = 250PA, VGS = 0V 40 V

Breakdown Voltage Temperature
Coefficient

ID = 250PA, referenced to
25

°C

33.5 mV/°C

Zero Gate Voltage Drain Current VDS = 32V, VGS = 0V 1 PA

Gate to Source Leakage Current VGS = ±20V, VDS = 0V ±100 nA

On Characteristics

V

GS(th)

'V
'T

r

DS(on)

g

FS

GS(th)

J

Gate to Source Threshold Voltage VGS = VDS, ID = 250PA 1 2.1 3 V

Gate to Source Threshold Voltage
Temperature Coefficient

Drain to Source On Resistance

ID = 250PA, referenced to

°C

25

= 10V, ID = 9A 19 24

V

GS

V

= 4.5V, ID = 7A 23 30

GS

= 10V, ID = 9A

V

GS

T

= 150°C

J

-5.7 mV/°C

32 41

Forward Transcondductance VDS = 5V, ID = 9A 29 S

Dynamic Characteristics

C

iss

C

oss

C

rss

R

g

Input Capacitance

Output Capacitance 112 150 pF

Reverse Transfer Capacitance 72 110 pF

= 20V, VGS = 0V,

V

DS

f = 1MHz

Gate Resistance f = 1MHz 1.1 :

780 990 pF

m:

®

MOSFET

Switching Characteristics

t

d(on)

t

r

t

d(off)

t

f

Q

Q

Q

Q

g

g

gs

gd

Turn-On Delay Time

Rise Time 310ns

Turn-Off Delay Time 19 34 ns

VDD = 20V, ID = A
V

= 10V, R

GS

GEN

= 6:

714ns

Fall Time 210ns

Total Gate Charge at 10V

Total Gate Charge at 5V 8.6 11 nC

Gate to Source Gate Charge 2.5 nC

= 20V, ID = 9A

V

DS

V

= 10V

GS

16 20 nC

Gate to Drain “Miller”Charge 3.7 nC

Drain-Source Diode Characteristics

V

SD

t

rr

Q

rr

Notes:
1: R

TJA

the drain pins. R

Source to Drain Diode Forward Voltage VGS= 0V, IS= 9A 0.87 1.2 V

Reverse Recovery Time IF = 9A, di/dt = 100A/Ps2538ns

Reverse Recovery Charge IF = 9A, di/dt = 100A/Ps1929nC

is the sum of the junction-to-case and case-to-ambient thermal resistance where the case thermal reference is defined as the solder mounting surface of

is guaranteed by design while R

TJC

is determined by the user’s board design.

TJA

a)

40 °C/W when mounted on a

2

pad of 2 oz copper

1 in

b)

96 °C/W when mounted on
a minimum pad

2: Pulse Test: Pulse Width < 300 Ps, Duty cycle < 2.0%.
3: Starting TJ=25°C, L= 0.1mH, IAS= 20 A, VDD=36 V, VGS= 10 V.

FDD8451 Rev. B2 www.fairchildsemi.com2