IRF6645 - International Rectifier

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8/5/05

IRF6645

DirectFET Power MOSFET 

DirectFET ISOMETRIC

PD - 97006

Applicable DirectFET Outline and Substrate Outline (see p.7,8 for details)

Fig 1. Typical On-Resistance vs. Gate Voltage

Typical values (unless otherwise specified)

Description

The IRF6645 combines the latest HEXFET® Power MOSFET Silicon technology with the advanced DirectFETTM packaging to achieve the

lowest on-state resistance in a package that has the footprint of an Micro8 and only 0.7 mm profile. The DirectFET package is compatible with

existing layout geometries used in power applications, PCB assembly equipment and vapor phase, infra-red or convection soldering techniques,

when application note AN-1035 is followed regarding the manufacturing methods and processes. The DirectFET package allows dual sided

cooling to maximize thermal transfer in power systems, improving previous best thermal resistance by 80%.

The IRF6645 is optimized for primary side bridge topologies in isolated DC-DC applications, for wide range universal input Telecom applications

(36V - 75V), and for secondary side synchronous rectification in regulated DC-DC topologies. The reduced total losses in the device coupled

with the high level of thermal performance enables high efficiency and low temperatures, which are key for system reliability improvements,

and makes this device ideal for high performance isolated DC-DC converters.

l RoHs Compliant Containing No Lead and Bromide 

l Low Profile (<0.7 mm)

l Dual Sided Cooling Compatible 

l Ultra Low Package Inductance

l Optimized for High Frequency Switching 

lIdeal for High Performance Isolated Converter

Primary Switch Socket

l Optimized for Synchronous Rectification

l Low Conduction Losses

l Compatible with existing Surface Mount Techniques 

 Click on this section to link to the appropriate technical paper.

 Click on this section to link to the DirectFET Website.

 Surface mounted on 1 in. square Cu board, steady state.

 TC measured with thermocouple mounted to top (Drain) of part.

 Repetitive rating; pulse width limited by max. junction temperature.

 Starting TJ = 25°C, L = 5.0mH, RG = 25Ω, IAS = 3.4A.

Notes:

Fig 2. Typical Total Gate Charge vs. Gate-to-Source Voltage

Absolute Maximum Ratin

Parameter Units

VDS Drain-to-Source Voltage V

VGS Gate-to-Source Voltage

ID @ TA = 25°C Continuous Drain Current, VGS @ 10V

ID @ TA = 70°C Continuous Drain Current, VGS @ 10V

ID @ TC = 25°C Continuous Drain Current, VGS @ 10V

IDM Pulsed Drain Current

EAS Single Pulse Avalanche Energy

IAR Avalanche Current

g

Max.

4.5

±20

100

5.7

3.4

4 6 8 10 12 14 16

VGS, Gate-to-Source Voltage (V)

Typical RDS(on) (

mΩ)

TJ = 25°C

TJ = 125°C

ID = 3.4A

0481216

QG Total Gate Charge (nC)

VGS, Gate-to-Source Voltage (V)

VDS= 80V

VDS= 50V

ID= 3.4A

VDSS VGS RDS(on)

100V max ±20V max 28mΩ@ 10V

Qg tot Qgd Vgs(th)

14nC 4.8nC 4.0V

SH SJ SP MZ MN

IRF6645

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Notes:

 Pulse width ≤ 400µs; duty cycle ≤ 2%.

 Repetitive rating; pulse width limited by max. junction temperature.

Electrical Characteristic @ TJ = 25°C (unless otherwise specified)

Parameter Min. Typ. Max. Units

BVDSS Drain-to-Source Breakdown Voltage 100 ––– ––– V

∆ΒVDSS/∆TJ Breakdown Voltage Temp. Coefficient ––– 0.12 ––– V/°C

RDS(on) Static Drain-to-Source On-Resistance ––– 28 35 mΩ

VGS(th) Gate Threshold Voltage 3.0 ––– 4.9 V

∆VGS(th)/∆TJGate Threshold Voltage Coefficient ––– -12 ––– mV/°C

IDSS Drain-to-Source Leakage Current ––– ––– 20 µA

––– ––– 250

IGSS Gate-to-Source Forward Leakage ––– ––– 100 nA

Gate-to-Source Reverse Leakage ––– ––– -100

gfs Forward Transconductance 7.4 ––– ––– S

QgTotal Gate Charge ––– 14 20

Qgs1 Pre-Vth Gate-to-Source Charge ––– 3.1 –––

Qgs2 Post-Vth Gate-to-Source Charge ––– 0.8 ––– nC

Qgd Gate-to-Drain Charge ––– 4.8 7.2

Qgodr Gate Charge Overdrive ––– 5.3 ––– See Fig. 15

Qsw Switch Charge (Qgs2 + Qgd)––– 5.6 –––

Qoss Output Charge ––– 7.2 ––– nC

RGGate Resistance ––– 1.0 ––– Ω

td(on) Turn-On Delay Time ––– 9.2 –––

trRise Time ––– 5.0 –––

td(off) Turn-Off Delay Time ––– 18 ––– ns

tfFall Time ––– 5.1 –––

Ciss Input Capacitance ––– 890 –––

Coss Output Capacitance ––– 180 ––– pF

Crss Reverse Transfer Capacitance ––– 40 –––

Coss Output Capacitance ––– 870 –––

Coss Output Capacitance ––– 100 –––

Diode Characteristics

Parameter Min. Typ. Max. Units

ISContinuous Source Current ––– ––– 25

(Body Diode) A

ISM Pulsed Source Current ––– ––– 45

(Body Diode)d

VSD Diode Forward Voltage ––– ––– 1.3 V

trr Reverse Recovery Time ––– 31 47 ns

Qrr Reverse Recovery Charge ––– 40 60 nC

ID = 3.4A

VDS = 80V, VGS = 0V, TJ = 125°C

VGS = 20V

VGS = -20V

VGS = 10V

VDS = 10V, ID = 3.4A

VDS = 50V

TJ = 25°C, IF = 3.4A, VDD = 50V

di/dt = 100A/µs c

TJ = 25°C, IS = 3.4A, VGS = 0V c

showing the

integral reverse

p-n junction diode.

VDS = VGS, ID = 50µA

VDS = 100V, VGS = 0V

Conditions

VGS = 0V, ID = 250µA

Reference to 25°C, ID = 1mA

VGS = 10V, ID = 5.7A c

VDS = 16V, VGS = 0V

VDD = 50V, VGS = 10Vc

VGS = 0V

ƒ = 1.0MHz

ID = 3.4A

MOSFET symbol

RG=6.2Ω

VDS = 25V

Conditions

VGS = 0V, VDS = 80V, f=1.0MHz

VGS = 0V, VDS = 1.0V, f=1.0MHz

IRF6645

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1E-006 1E-005 0.0001 0.001 0.01 0.1 110 100

t1 , Rectangular Pulse Duration (sec)

0.01

0.1

100

Thermal Response ( Z

thJA )

0.20

0.10

D = 0.50

0.02

0.01

0.05

SINGLE PULSE

( THERMAL RESPONSE )

Notes:

1. Duty Factor D = t1/t2

2. Peak Tj = Pdm x Zthja + Ta

Fig 3. Maximum Effective Transient Thermal Impedance, Junction-to-Ambient 

 Surface mounted on 1 in. square Cu

board (still air).

 Mounted on minimum

footprint full size board with

metalized back and with small

clip heatsink (still air)

 Mounted to a PCB with

small clip heatsink (still air)

 Surface mounted on 1 in. square Cu, steady state.

 Used double sided cooling , mounting pad.

 Mounted on minimum footprint full size board with metalized

back and with small clip heatsink.

Notes:

 TC measured with thermocouple incontact with top (Drain) of part.

 Rθ is measured at TJ of approximately 90°C.

τJ

τ1

τ2

τ2τ3

τ3

R1R2

R2R3

Ci= τi/Ri

τ4

τC

τ5

Ri (°C/W) τi (sec)

0.6677 0.000066

1.0463 0.000896

1.5612 0.004386

29.2822 0.686180

25.4550 32

Absolute Maximum Ratin

Parameter Units

PD @TA = 25°C Power Dissipation

PD @TA = 70°C Power Dissipation

PD @TC = 25°C Power Dissipation

TP Peak Soldering Temperature °C

TJ Operating Junction and

TSTG Storage Temperature Range

Thermal Resistance

Parameter Typ. Max. Units

RθJA Junction-to-Ambient

––– 58

RθJA Junction-to-Ambient

12.5 –––

RθJA Junction-to-Ambient

20 ––– °C/W

RθJC Junction-to-Case

––– 3.0

RθJ-PCB Junction-to-PCB Mounted 1.0 –––

270

-40 to + 150

Max.

3.0

1.4

IRF6645

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Fig 5. Typical Output Characteristics

Fig 4. Typical Output Characteristics

Fig 6. Typical Transfer Characteristics Fig 7. Normalized On-Resistance vs. Temperature

Fig 8. Typical Capacitance vs.Drain-to-Source Voltage Fig 9. Typical On-Resistance vs. Drain Current

0.1 110 100

VDS, Drain-to-Source Voltage (V)

0.1

100

ID, Drain-to-Source Current (A)

≤60µs PULSE WIDTH

Tj = 25°C

6.0V

VGS

TOP 15V

10V

8.0V

7.0V

BOTTOM 6.0V

0.1 110 100

VDS, Drain-to-Source Voltage (V)

100

ID, Drain-to-Source Current (A)

≤60µs PULSE WIDTH

Tj = 150°C

6.0V

VGS

TOP 15V

10V

8.0V

7.0V

BOTTOM 6.0V

4.0 5.0 6.0 7.0 8.0

VGS, Gate-to-Source Voltage (V)

0.1

100

ID, Drain-to-Source Current

(Α)

TJ = 150°C

TJ = 25°C

TJ = -40°C

VDS = 10V

≤60µs PULSE WIDTH

-60 -40 -20 020 40 60 80 100 120 140 160

TJ , Junction Temperature (°C)

0.5

1.0

1.5

2.0

Typical RDS(on) (Normalized)

ID = 5.7A

VGS = 10V

110 100

VDS, Drain-to-Source Voltage (V)

100

1000

10000

C, Capacitance(pF)

VGS = 0V, f = 1 MHZ

Ciss = Cgs + Cgd, Cds SHORTED

Crss = Cgd

Coss = Cds + Cgd

Coss

Crss

Ciss

010 20 30 40 50

ID, Drain Current (A)

Typical RDS(on) (mΩ)

TA= 25°C

VGS = 7.0V

VGS = 8.0V

VGS = 10V

VGS = 15V

IRF6645

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Fig 13. Typical Threshold Voltage vs.

Junction Temperature

Fig 12. Maximum Drain Current vs. Ambient Temperature

Fig 10. Typical Source-Drain Diode Forward Voltage Fig11. Maximum Safe Operating Area

Fig 14. Maximum Avalanche Energy vs. Drain Current

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1

VSD, Source-to-Drain Voltage (V)

0.1

1.0

10.0

100.0

ISD, Reverse Drain Current (A)

VGS = 0V

TJ = 150°C

TJ = 25°C

TJ = -40°C

25 50 75 100 125 150

Starting TJ, Junction Temperature (°C)

100

120

EAS, Single Pulse Avalanche Energy (mJ)

I D

TOP 1.5A

2.4A

BOTTOM 3.4A

0.1 1.0 10.0 100.0 1000.0

VDS , Drain-toSource Voltage (V)

0.1

100

1000

ID, Drain-to-Source Current (A)

TA = 25°C

Tj = 150°C

Single Pulse

1msec

10msec

OPERATION IN THIS AREA

LIMITED BY RDS(on)

100µsec

25 50 75 100 125 150

TJ , Ambient Temperature (°C)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

ID , Drain Current (A)

-75 -50 -25 025 50 75 100 125 150

TJ , Temperature ( °C )

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

VGS(th) Gate threshold Voltage (V)

ID = 1.0A

ID = 1.0mA

ID = 250µA

ID = 50µA

IRF6645

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D.U.T. VDS

3mA

VGS

.3µF

50KΩ

.2µF

12V

Current Regulator

Same Type as D.U.T.

Current Sampling Resistors

Fig 15a. Gate Charge Test Circuit Fig 15b. Gate Charge Waveform

Vds

Vgs

Vgs(th)

Qgs1 Qgs2 Qgd Qgodr

Fig 16c. Unclamped Inductive Waveforms

(BR)DSS

Fig 16b. Unclamped Inductive Test Circuit

Fig 17b. Switching Time Waveforms

VGS

VDS

90%

10%

td(on) td(off)

trtf

Fig 17a. Switching Time Test Circuit

0.01

Ω

D.U.T

VDS

-V

DRIVER

15V

20V

VDS

Pulse Width ≤ 1 µs

Duty Factor ≤ 0.1 %

VGS

D.U.T.

10V

VDD

VGS

IRF6645

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DirectFET Substrate and PCB Layout, SJ Outline

(Small Size Can, J-Designation).

Please see DirectFET application note AN-1035 for all details regarding the assembly of DirectFET.

This includes all recommendations for stencil and substrate designs.

Fig 18. Diode Reverse Recovery Test Circuit for N-Channel

HEXFET® Power MOSFETs

P.W. Period

di/dt

Diode Recovery

dv/dt

Ripple ≤5%

Body Diode Forward Drop

Re-Applied

Voltage

Reverse

Recovery

Current

Body Diode Forward

Current

VGS=10V

VDD

ISD

Driver Gate Drive

D.U.T. ISD Waveform

D.U.T. VDS Waveform

Inductor Curent

D = P. W .

Period

* VGS = 5V for Logic Level Devices

Inductor Current

Circuit Layout Considerations

• Low Stray Inductance

• Ground Plane

• Low Leakage Inductance

Current Transformer

• di/dt controlled by RG

• Driver same type as D.U.T.

• ISD controlled by Duty Factor "D"

• D.U.T. - Device Under Test







RGVDD

D.U.T



G = GATE

D = DRAIN

S = SOURCE

IRF6645

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DirectFET Outline Dimension, SJ Outline

(Small Size Can, J-Designation).

Please see DirectFET application note AN-1035 for all details regarding the assembly of DirectFET.

This includes all recommendations for stencil and substrate designs.

DirectFET Part Marking

MIN

0.187

0.146

0.108

0.014

0.023

0.027

0.039

0.090

0.019

0.001

0.003

MAX

4.85

3.95

2.85

0.45

0.62

0.72

1.02

2.32

0.58

0.08

0.17

MIN

4.75

3.70

2.75

0.35

0.58

0.68

0.98

2.28

0.48

0.03

0.08

CODE



MAX

0.191

0.156

0.112

0.018

0.024

0.028

0.040

0.091

0.023

0.003

0.007

DIMENSIONS

METRIC IMPERIAL

IRF6645

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DirectFET Tape & Reel Dimension (Showing component orientation).

Data and specifications subject to change without notice.

This product has been designed and qualified for the Consumer market.

Qualification Standards can be found on IR’s Web site.

IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105

TAC Fax: (310) 252-7903

Visit us at www.irf.com for sales contact information.08/05

REEL DIMENSIONS

NOTE: Controlling dimensions in mm

Std reel quantity is 4800 parts. (ordered as IRF6645). For 1000 parts on 7" reel,

order IRF6645TR1

STANDARD OPTION (QTY 4800)

MIN

330.0

20.2

12.8

1.5

100.0

N.C

12.4

11.9

CODE

MAX

N.C

13.2

N.C

18.4

14.4

15.4

MIN

12.992

0.795

0.504

0.059

3.937

N.C

0.488

0.469

MAX

N.C

0.520

N.C

0.724

0.567

0.606

METRIC IMPERIAL

TR1 OPTION (QTY 1000)

IMPERIAL

MIN

6.9

0.75

0.53

0.059

2.31

N.C

0.47

MAX

N.C

12.8

N.C

13.50

12.01

MIN

177.77

19.06

13.5

1.5

58.72

N.C

11.9

METRIC

MAX

N.C

0.50

N.C

0.53

N.C

MIN

7.90

3.90

11.90

5.45

4.00

5.00

1.50

NOTE: CONTROLLING

DIMENSIONS IN MM MAX

8.10

4.10

12.30

5.55

4.20

5.20

N.C

1.60

MAX

0.319

0.161

0.484

0.219

0.165

0.205

N.C

0.063

DIMENSIONS

METRIC IMPERIAL

Note: For the most current drawings please refer to the IR website at:

http://www.irf.com/package/