Fairchild FDMS8670S service manual

May 2009

FDMS8670S N-Channel PowerTrench

FDMS8670S
N-Channel PowerTrench

30V, 42A, 3.5m:

Features

 Max r

 Max r

 Advanced Package and Silicon combination for low r

and high efficiency

 SyncFET Schottky Body Diode

 MSL1 robust package design

 RoHS Compliant

= 3.5m: at VGS = 10V, ID = 20A

DS(on)

= 5.0m: at VGS = 4.5V, ID = 17A

DS(on)

Top

Bottom

®

SyncFET

General Description

The FDMS8670S has been designed to minimize losses in
power conversion application. Advancements in both silicon and
package technologies have been combined to offer the lowest
r

DS(on)

DS(on)

device has the added benefit of an efficient monolithic Schottky
body diode.

Application

 Synchronous Rectifier for DC/DC Converters

 Notebook Vcore/ GPU low side switch

 Networking Point of Load low side switch

 Telecom secondary side rectification

Pin 1

S

S

S

G

TM

tm

while maintaining excellent switching performance. This

G

5

D

6

D

4

S

3

®

SyncFET

TM

D

D

D

D

D

7

8

D

2

1

Power 56

MOSFET Maximum Ratings T

Symbol Parameter Ratings Units

V

DS

V

GS

I

D

P

D

, T

T

J

STG

Drain to Source Voltage 30 V

Gate to Source Voltage ±20 V

Drain Current -Continuous (Package limited) TC= 25°C 42

-Continuous (Silicon limited) T

 -Continuous (Silicon limited) T

-Continuous T

-Pulsed 200

Power Dissipation TC = 25°C 78

Power Dissipation T

Operating and Storage Junction Temperature Range -55 to +150 °C

= 25°C unless otherwise noted

A

= 25°C 116

C

= 100°C 74

C

= 25°C 20

A

= 25°C (Note 1a) 2.5

A

= 85°C (Note 1a) 1.3

A

Thermal Characteristics

R

TJC

R

TJA

Thermal Resistance, Junction to Case 1.6

Thermal Resistance, Junction to Ambient (Note 1a) 50

Package Marking and Ordering Information

S

S

A

WPower Dissipation T

°C/W

Device Marking Device Package Reel Size Tape Width Quantity

FDMS8670S FDMS8670S Power 56 13’’ 12mm 3000 units

©2009 Fairchild Semiconductor Corporation
FDMS8670S Rev.C5

1

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FDMS8670S 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 = 1mA, VGS = 0V 30 V

Breakdown Voltage Temperature
Coefficient

= 10mA, referenced to 25°C 17 mV/°C

I

D

Zero Gate Voltage Drain Current VDS = 24V, VGS= 0V 500 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 = 1mA 1 1.5 3 V

Gate to Source Threshold Voltage
Temperature Coefficient

Drain to Source On Resistance

= 50mA, referenced to 25°C -2.8 mV/°C

I

D

V

= 10V, ID = 20A 2.8 3.5

GS

= 4.5V, ID = 17A 3.6 5.0

GS

= 10V, ID = 20A ,TJ = 125°C 3.9 6.0

V

GS

Forward Transconductance VDS = 10V, ID = 20A 98 S

Dynamic Characteristics

C

iss

C

oss

C

rss

R

g

Input Capacitance

Output Capacitance 865 1150 pF

Reverse Transfer Capacitance 320 480 pF

= 15V, VGS = 0V

V

DS

f = 1MHz

Gate Resistance f = 1MHz 1.4 5.0 :

3005 4000 pF

Switching Characteristics

t

d(on)

t

r

t

d(off)

t

f

Q

g(TOT)

Q

g(4.5V)

Q

gs

Q

gd

Turn-On Delay Time

Rise Time 19 35 ns

Turn-Off Delay Time 37 60 ns

VDD = 15V, ID = 20A
V

= 10V, R

GS

GEN

= 5:

14 26 ns

Fall Time 10 20 ns

Total Gate Charge at 10V VGS= 0V to 10V

Total Gate Charge at 4.5V VGS= 0V to 4.5V 24 34 nC

Gate to Source Gate Charge 8 nC

V

DS

= 20A

I

D

= 15V

52 73 nC

Gate to Drain “Miller” Charge 10 nC

m:V

®

SyncFET

TM

Drain-Source Diode Characteristics

V

SD

t

rr

Q

rr

Notes:

1: R

TJA

the user's board design.

2: Pulse time < 300Ps, Duty cycle < 2%.

FDMS8670S Rev.C5

Source to Drain Diode Forward Voltage VGS= 0V, IS= 2A 0.4 0.7 V

Reverse Recovery Time

Reverse Recovery Charge 24 39 nC

is determined with the device mounted on a 1in2 pad 2 oz copper pad on a 1.5 x 1.5 in. board of FR-4 material. R

I

F

a. 50°C/W when mounted on
a 1 in2pad of 2 oz copper

= 20A, di/dt = 300A/Ps

2

26 42 ns

is guaranteed by design while R

TJC

b. 125°C/W when mounted on a
minimum pad of 2 oz copper

is determined by

TCA

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FDMS8670S N-Channel PowerTrench

Typical Characteristics T

180

150

120

90

60

, DRAIN CURRENT (A)

D

I

30

0

01234

Figure 1.

1.8

ID = 20A
V

1.6

1.4

1.2

1.0

NORMALIZED

0.8

0.6

DRAIN TO SOURCE ON-RESISTANCE

-75 -50 -25 0 25 50 75 100 125 150

VGS = 10V

VGS = 4.5V

VGS = 4V

VDS, DRAIN TO SOURCE VOLTAGE (V)

On Region Characteristics Figure 2.

= 10V

GS

TJ, JUNCTION TEMPERATURE (oC)

PULSE DURATION = 80Ps
DUTY CYCLE = 0.5%MAX

= 25°C unless otherwise noted

J

VGS = 3.5V

VGS = 3V

4.0

3.5

3.0

2.5

2.0

NORMALIZED

1.5

1.0

0.5

DRAIN TO SOURCE ON-RESISTANCE

0 30 60 90 120 150 180

VGS = 3V

ID, DRAIN CURRENT(A)

PULSE DURATION = 80Ps
DUTY CYCLE = 0.5%MAX

VGS = 3.5V

VGS = 4.5V

VGS = 10V

N o r m a l i z e d O n - R e s i s t a n c e

vs Drain Current and Gate Voltage

10

ID= 20A

(m:)

8

6

, DRAIN TO

4

DS(on)

r

TJ= 25oC

SOURCE ON-RESISTANCE

2

345678910

VGS, GATE TO SOURCE VOLTAGE (V)

PULSE DURATION = 80Ps
DUTY CYCLE = 0.5%MAX

TJ= 125oC

VGS = 4V

®

SyncFET

TM

F i g u r e 3 . N o r m a l i z e d O n R e s i s t a n c e

150

120

90

60

30

, DRAIN CURRENT (A)

D

I

0

Figure 5. Transfer Characteristics

FDMS8670S Rev.C5

vs Junction Temperature

PULSE DURATION = 80Ps
DUTY CYCLE = 0.5%MAX

TJ= 125oC

1234

VGS, GATE TO SOURCE VOLTAGE (V)

TJ = 25oC

TJ = -55oC

, REVERSE DRAIN CURRENT (A)
I

3

Figure 4.

O n - R es i s t a n c e vs G a t e t o

Source Voltage

20

10

VGS= 0V

1

TJ= 125oC

TJ = 25oC

0.1

0.01

S

1E-3

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

VSD, BODY DIODE FORWARD VOLTAGE (V)

Figure 6.

S o u r ce t o D r a i n Di o d e

TJ = -55oC

Forward Voltage vs Source Current

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