PD - 95440B
IRLR7843PbF
IRLU7843PbF
Applications
l High Frequency Synchronous Buck
Converters for Computer Processor Power
l High Frequency Isolated DC-DC
Converters with Synchronous Rectification
for Telecom and Industrial Use
l Lead-Free
HEXFET® Power MOSFET
VDSS
30V
Benefits
l Very Low RDS(on) at 4.5V VGS
l Ultra-Low Gate Impedance
l Fully Characterized Avalanche Voltage
and Current
RDS(on) max
3.3m:
D-Pak
IRLR7843PbF
Qg
34nC
I-Pak
IRLU7843PbF
Absolute Maximum Ratings
Parameter
Max.
Units
30
V
VDS
Drain-to-Source Voltage
VGS
Gate-to-Source Voltage
Continuous Drain Current, VGS @ 10V
± 20
161
Continuous Drain Current, VGS @ 10V
Pulsed Drain Current
113
ID @ TC = 25°C
ID @ TC = 100°C
IDM
c
PD @TC = 25°C
Maximum Power Dissipation
PD @TC = 100°C
Maximum Power Dissipation
TJ
Linear Derating Factor
Operating Junction and
TSTG
Storage Temperature Range
f
f
A
620
g
g
140
W
71
0.95
-55 to + 175
Soldering Temperature, for 10 seconds
W/°C
°C
300 (1.6mm from case)
Thermal Resistance
Parameter
RθJC
RθJA
Junction-to-Case
Junction-to-Ambient (PCB Mount)
RθJA
Junction-to-Ambient
Notes through
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g
Typ.
Max.
–––
1.05
–––
50
–––
110
Units
°C/W
are on page 11
1
04/30/08
IRLR/U7843PbF
Static @ TJ = 25°C (unless otherwise specified)
Parameter
BVDSS
∆ΒVDSS/∆TJ
RDS(on)
Min. Typ. Max. Units
30
–––
–––
Breakdown Voltage Temp. Coefficient
Static Drain-to-Source On-Resistance
–––
–––
19
2.6
–––
3.3
mV/°C Reference to 25°C, ID = 1mA
mΩ VGS = 10V, ID = 15A
VGS(th)
∆VGS(th)/∆TJ
IDSS
Gate Threshold Voltage
–––
1.4
3.2
–––
4.0
2.3
VGS = 4.5V, ID = 12A
VDS = VGS, ID = 250µA
Gate Threshold Voltage Coefficient
Drain-to-Source Leakage Current
–––
–––
-5.4
–––
–––
1.0
IGSS
Gate-to-Source Forward Leakage
–––
–––
–––
–––
150
100
nA
VDS = 24V, VGS = 0V, TJ = 125°C
VGS = 20V
Gate-to-Source Reverse Leakage
Forward Transconductance
–––
37
–––
–––
-100
–––
S
VGS = -20V
VDS = 15V, ID = 12A
Total Gate Charge
Pre-Vth Gate-to-Source Charge
–––
–––
34
9.1
50
–––
Post-Vth Gate-to-Source Charge
Gate-to-Drain Charge
–––
–––
2.5
12
–––
–––
Qgodr
Qsw
Gate Charge Overdrive
Switch Charge (Qgs2 + Qgd)
–––
–––
10
15
–––
–––
Qoss
td(on)
Output Charge
Turn-On Delay Time
–––
–––
21
25
–––
–––
tr
td(off)
Rise Time
Turn-Off Delay Time
–––
–––
42
34
–––
–––
tf
Ciss
Fall Time
Input Capacitance
–––
–––
19
4380
–––
–––
Coss
Crss
Output Capacitance
Reverse Transfer Capacitance
–––
–––
940
430
–––
–––
gfs
Qg
Qgs1
Qgs2
Qgd
V
Conditions
Drain-to-Source Breakdown Voltage
V
VGS = 0V, ID = 250µA
e
e
mV/°C
µA VDS = 24V, VGS = 0V
VDS = 15V
nC
VGS = 4.5V
ID = 12A
See Fig. 16
nC
ns
VDS = 15V, VGS = 0V
VDD = 15V, VGS = 4.5V
e
ID = 12A
Clamped Inductive Load
VGS = 0V
pF
VDS = 15V
ƒ = 1.0MHz
Avalanche Characteristics
EAS
IAR
Parameter
Single Pulse Avalanche Energy
Avalanche Current
EAR
Repetitive Avalanche Energy
c
d
c
Typ.
–––
–––
Max.
1440
12
Units
mJ
A
–––
14
mJ
Diode Characteristics
Parameter
Min. Typ. Max. Units
161
f
Conditions
IS
Continuous Source Current
–––
–––
ISM
(Body Diode)
Pulsed Source Current
–––
–––
620
VSD
(Body Diode)
Diode Forward Voltage
–––
–––
1.0
V
p-n junction diode.
TJ = 25°C, IS = 12A, VGS = 0V
trr
Qrr
Reverse Recovery Time
Reverse Recovery Charge
–––
–––
39
36
59
54
ns
nC
TJ = 25°C, IF = 12A, VDD = 15V
di/dt = 100A/µs
ton
Forward Turn-On Time
2
c
MOSFET symbol
A
showing the
integral reverse
e
e
Intrinsic turn-on time is negligible (turn-on is dominated by LS+LD)
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IRLR/U7843PbF
1000
VGS
10V
4.5V
3.7V
3.5V
3.3V
3.0V
2.7V
BOTTOM 2.5V
1000
VGS
10V
4.5V
3.7V
3.5V
3.3V
3.0V
2.7V
BOTTOM 2.5V
TOP
100
10
2.5V
1
ID, Drain-to-Source Current (A)
ID, Drain-to-Source Current (A)
TOP
20µs PULSE WIDTH
Tj = 25°C
0.1
0.1
1
10
100
2.5V
10
1
0.1
100
Fig 1. Typical Output Characteristics
2.0
T J = 25°C
VDS = 15V
20µs PULSE WIDTH
2.0
3.0
4.0
VGS , Gate-to-Source Voltage (V)
Fig 3. Typical Transfer Characteristics
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100
ID = 30A
VGS = 10V
1.5
(Normalized)
RDS(on) , Drain-to-Source On Resistance
ID, Drain-to-Source Current (Α)
T J = 175°C
1
10
Fig 2. Typical Output Characteristics
1000
10
1
VDS, Drain-to-Source Voltage (V)
VDS, Drain-to-Source Voltage (V)
100
20µs PULSE WIDTH
Tj = 175°C
1.0
0.5
5.0
-60 -40 -20 0
20 40 60 80 100 120 140 160 180
T J , Junction Temperature (°C)
Fig 4. Normalized On-Resistance
vs. Temperature
3
IRLR/U7843PbF
VGS = 0V,
f = 1 MHZ
Ciss = C gs + Cgd, C ds
Crss = C gd
12
ID= 12A
SHORTED
VGS, Gate-to-Source Voltage (V)
100000
C, Capacitance (pF)
Coss = Cds + Cgd
10000
Ciss
Coss
1000
Crss
8
6
4
2
0
100
1
10
0
100
20
60
80
Fig 6. Typical Gate Charge vs.
Gate-to-Source Voltage
Fig 5. Typical Capacitance vs.
Drain-to-Source Voltage
1000.0
10000
ID, Drain-to-Source Current (A)
ISD, Reverse Drain Current (A)
40
Q G Total Gate Charge (nC)
VDS, Drain-to-Source Voltage (V)
100.0
OPERATION IN THIS AREA
LIMITED BY R DS(on)
1000
T J = 175°C
10.0
1.0
T J = 25°C
100
100µsec
10
VGS = 0V
1
0.1
0.0
0.5
1.0
VSD, Source-toDrain Voltage (V)
Fig 7. Typical Source-Drain Diode
Forward Voltage
4
VDS= 24V
VDS= 15V
10
1.5
1msec
Tc = 25°C
Tj = 175°C
Single Pulse
0.1
1.0
10msec
10.0
100.0
1000.0
VDS , Drain-toSource Voltage (V)
Fig 8. Maximum Safe Operating Area
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IRLR/U7843PbF
160
2.5
VGS(th) Gate threshold Voltage (V)
ID , Drain Current (A)
LIMITED BY PACKAGE
120
80
40
2.0
ID = 250µA
1.5
1.0
0.5
0
25
50
75
100
125
150
0.0
175
-75 -50 -25
T C , Case Temperature (°C)
0
25
50
75
100 125 150 175
T J , Temperature ( °C )
Fig 9. Maximum Drain Current vs.
Case Temperature
Fig 10. Threshold Voltage vs. Temperature
Thermal Response ( Z thJC )
10
1
D = 0.50
0.20
0.10
0.1
τJ
0.05
0.02
0.01
0.01
R1
R1
τJ
τ1
R2
R2
τC
τ2
τ1
τ2
τ
Ri (°C/W)
0.5084
τi (sec)
0.000392
0.5423
0.011108
Ci= τi/Ri
Ci i/Ri
Notes:
1. Duty Factor D = t1/t2
2. Peak Tj = P dm x Zthjc + Tc
SINGLE PULSE
( THERMAL RESPONSE )
0.001
1E-006
1E-005
0.0001
0.001
0.01
0.1
t1 , Rectangular Pulse Duration (sec)
Fig 11. Maximum Effective Transient Thermal Impedance, Junction-to-Case
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5
IRLR/U7843PbF
15V
+
V
- DD
IAS
A
0.01Ω
tp
Fig 12a. Unclamped Inductive Test Circuit
V(BR)DSS
tp
EAS, Single Pulse Avalanche Energy (mJ)
D.U.T
RG
20V
VGS
DRIVER
L
VDS
6000
ID
8.6A
9.6A
BOTTOM 12A
TOP
5000
4000
3000
2000
1000
0
25
50
75
100
125
150
175
Starting T J, Junction Temperature (°C)
Fig 12c. Maximum Avalanche Energy
Vs. Drain Current
I AS
LD
VDS
Fig 12b. Unclamped Inductive Waveforms
+
VDD D.U.T
Current Regulator
Same Type as D.U.T.
VGS
Pulse Width < 1µs
Duty Factor < 0.1%
50KΩ
12V
.2µF
.3µF
D.U.T.
+
V
- DS
Fig 14a. Switching Time Test Circuit
VDS
90%
VGS
3mA
IG
ID
Current Sampling Resistors
Fig 13. Gate Charge Test Circuit
10%
VGS
td(on)
tr
td(off)
tf
Fig 14b. Switching Time Waveforms
6
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IRLR/U7843PbF
D.U.T
Driver Gate Drive
P.W.
+
+
-
-
*
D.U.T. ISD Waveform
Reverse
Recovery
Current
+
RG
•
•
•
•
dv/dt controlled by RG
Driver same type as D.U.T.
I SD controlled by Duty Factor "D"
D.U.T. - Device Under Test
P.W.
Period
VGS=10V
Circuit Layout Considerations
• Low Stray Inductance
• Ground Plane
• Low Leakage Inductance
Current Transformer
D=
Period
V DD
+
-
Body Diode Forward
Current
di/dt
D.U.T. VDS Waveform
Diode Recovery
dv/dt
Re-Applied
Voltage
Body Diode
VDD
Forward Drop
Inductor Curent
ISD
Ripple ≤ 5%
* VGS = 5V for Logic Level Devices
Fig 15. Peak Diode Recovery dv/dt Test Circuit for N-Channel
HEXFET® Power MOSFETs
Id
Vds
Vgs
Vgs(th)
Qgs1 Qgs2
Qgd
Qgodr
Fig 16. Gate Charge Waveform
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7
IRLR/U7843PbF
Power MOSFET Selection for Non-Isolated DC/DC Converters
Control FET
Synchronous FET
Special attention has been given to the power losses
in the switching elements of the circuit - Q1 and Q2.
Power losses in the high side switch Q1, also called
the Control FET, are impacted by the Rds(on) of the
MOSFET, but these conduction losses are only about
one half of the total losses.
The power loss equation for Q2 is approximated
by;
*
Ploss = Pconduction + Pdrive + Poutput
(
2
Ploss = Irms × Rds(on)
)
Power losses in the control switch Q1 are given
by;
+ (Qg × Vg × f )
Ploss = Pconduction+ Pswitching+ Pdrive+ Poutput
⎛Q
⎞
+ ⎜ oss × Vin × f + (Qrr × Vin × f )
⎝ 2
⎠
This can be expanded and approximated by;
*dissipated primarily in Q1.
Ploss = (Irms 2 × Rds(on ) )
⎛
Qgd
+⎜I ×
× Vin ×
ig
⎝
⎞ ⎛
Qgs 2
⎞
f⎟ + ⎜ I ×
× Vin × f ⎟
ig
⎠ ⎝
⎠
+ (Qg × Vg × f )
+
⎛ Qoss
× Vin × f ⎞
⎝ 2
⎠
This simplified loss equation includes the terms Qgs2
and Qoss which are new to Power MOSFET data sheets.
Qgs2 is a sub element of traditional gate-source
charge that is included in all MOSFET data sheets.
The importance of splitting this gate-source charge
into two sub elements, Qgs1 and Qgs2, can be seen from
Fig 16.
Qgs2 indicates the charge that must be supplied by
the gate driver between the time that the threshold
voltage has been reached and the time the drain current rises to Idmax at which time the drain voltage begins to change. Minimizing Q gs2 is a critical factor in
reducing switching losses in Q1.
Qoss is the charge that must be supplied to the output capacitance of the MOSFET during every switching cycle. Figure A shows how Qoss is formed by the
parallel combination of the voltage dependant (nonlinear) capacitances Cds and Cdg when multiplied by
the power supply input buss voltage.
For the synchronous MOSFET Q2, Rds(on) is an important characteristic; however, once again the importance of gate charge must not be overlooked since
it impacts three critical areas. Under light load the
MOSFET must still be turned on and off by the control IC so the gate drive losses become much more
significant. Secondly, the output charge Qoss and reverse recovery charge Qrr both generate losses that
are transfered to Q1 and increase the dissipation in
that device. Thirdly, gate charge will impact the
MOSFETs’ susceptibility to Cdv/dt turn on.
The drain of Q2 is connected to the switching node
of the converter and therefore sees transitions between ground and Vin. As Q1 turns on and off there is
a rate of change of drain voltage dV/dt which is capacitively coupled to the gate of Q2 and can induce
a voltage spike on the gate that is sufficient to turn
the MOSFET on, resulting in shoot-through current .
The ratio of Qgd/Qgs1 must be minimized to reduce the
potential for Cdv/dt turn on.
Figure A: Qoss Characteristic
8
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IRLR/U7843PbF
D-Pak (TO-252AA) Package Outline
D-Pak (TO-252AA) Part Marking Information
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Note: For the most current drawing please refer to IR website at http://www.irf.com/package/
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9
IRLR/U7843PbF
I-Pak (TO-251AA) Package Outline
Dimensions are shown in millimeters (inches)
I-Pak (TO-251AA) Part Marking Information
(;$03/( 7+,6,6$1,5)8
:,7+$66(0%/<
/27&2'(
$66(0%/('21::
,17+($66(0%/</,1($
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5(&7,),(5
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$ $66(0%/<6,7(&2'(
Note: For the most current drawing please refer to IR website at http://www.irf.com/package/
10
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IRLR/U7843PbF
D-Pak (TO-252AA) Tape & Reel Information
Dimensions are shown in millimeters (inches)
TR
TRR
16.3 ( .641 )
15.7 ( .619 )
12.1 ( .476 )
11.9 ( .469 )
FEED DIRECTION
TRL
16.3 ( .641 )
15.7 ( .619 )
8.1 ( .318 )
7.9 ( .312 )
FEED DIRECTION
NOTES :
1. CONTROLLING DIMENSION : MILLIMETER.
2. ALL DIMENSIONS ARE SHOWN IN MILLIMETERS ( INCHES ).
3. OUTLINE CONFORMS TO EIA-481 & EIA-541.
13 INCH
16 mm
NOTES :
1. OUTLINE CONFORMS TO EIA-481.
Notes:
Repetitive rating; pulse width limited by
max. junction temperature.
Starting TJ = 25°C, L = 20mH, RG = 25Ω,
IAS = 12A.
Pulse width ≤ 400µs; duty cycle ≤ 2%.
Calculated continuous current based on maximum allowable
junction temperature. Package limitation current is 30A.
When mounted on 1" square PCB (FR-4 or G-10 Material).
For recommended footprint and soldering techniques refer to
application note #AN-994.
Note: For the most current drawing please refer to IR website at http://www.irf.com/package/
Data and specifications subject to change without notice.
This product has been designed and qualified for the Industrial 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.04/2008
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11