PD-93839C
IRLR8503
IRLR8503
•
•
•
•
N-Channel Application-Specific MOSFET
Ideal for CPU Core DC-DC Converters
Low Conduction Losses
Minimizes Parallel MOSFETs for high current
applications
HEXFET® MOSFET for DC-DC Converters
D
• 100% RG Tested
Description
This new device employs advanced HEXFET Power
MOSFET technology to achieve very low on-resistance.
The reduced conduction losses makes it ideal for high
efficiency DC-DC converters that power the latest
generation of microprocessors.
G
S
D-Pak
DEVICE RATINGS (MAX. Values)
The IRLR8503 has been optimized and is 100% tested for
all parameters that are critical in synchronous buck
converters including RDS(on), gate charge and Cdv/dtinduced turn-on immunity. The IRLR8503 offers an
extremely low combination of Qsw & RDS(on) for reduced
losses in control FET applications.
IRLR8503
The package is designed for vapor phase, infra-red,
convection, or wave soldering techniques. Power
dissipation of greater than 2W is possible in a typical PCB
mount application.
VDS
RDS(on)
QG
QSW
30V
18 mΩ
QOSS
29.5 nC
20 nC
8 nC
Absolute Maximum Ratings
Symbol
IRLR8503
Drain-Source Voltage
Parameter
VDS
30
Gate-Source Voltage
VGS
±20
Continuous Drain or Source Current
TC = 25°C
TC = 90°C
c
T
Power Dissipation g
T
C
= 25°C
C
= 90°C
62
PD
TJ , TSTG
Continuous Source Current (Body Diode)
IS
15
Pulsed Source Current
ISM
196
c
A
32
196
30
-55 to 150
Junction & Storage Temperature Range
V
44
ID
IDM
Pulsed Drain Current
Units
W
°C
A
Thermal Resistance
Parameter
Maximum Junction-to-Ambient
Maximum Junction-to-Lead
www.irf.com
h
eh
Symbol
Typ
Max
RθJA
–––
50
RθJL
–––
2.0
Units
°C/W
1
5/26/05
IRLR8503
Electrical Characteristics
Parameter
Symbol
Drain-to-Source Breadown Voltage*
V(BR)DSS
Static Drain-Source On-Resistance*
RDS(on)
Gate Threshold Voltage*
VGS(th)
Drain-Source Leakage Current
IDSS
Gate-Source Leakage Current*
Total Gate Charge, Control FET*
Conditions
Min Typ Max Units
30
–––
–––
–––
11
16
–––
1.0
13
–––
18
3.0
–––
–––
1.0
–––
–––
150
IGSS
–––
––– ±100
Qg
–––
15
Total Gate Charge, Synch FET*
Qg
–––
Pre-Vth Gate-to-Source Charge
Qgs1
–––
Post-Vth Gate-to-Source Charge
Qgs2
–––
1.3
–––
Gate-to-Drain Charge
Qgd
–––
4.1
–––
Switch Charge* (Qgs2 + Qgd)
QSW
–––
5.4
8
Output Charge*
QOSS
–––
23
29.5
Gate Resistance
RG
0.4
–––
1.1
Turn-On Delay Time
td(on)
–––
10
–––
Drain Voltage Rise Time
trV
–––
18
–––
Turn-Off Delay Time
td(off)
–––
11
–––
Drain Voltage Fall Time
tfV
–––
3
–––
Input Capacitance
Ciss
––– 1650 –––
Output Capacitance
Coss
–––
650
–––
Reverse Transfer Capacitance
Crss
–––
58
–––
V
VGS = 0V, ID = 250µA
mΩ
VGS = 10V, ID = 15A
VGS = 4.5V, 1D = 15A
V
VDS = VGS, ID = 250µA
µA
nA
d
VDS = 30V, VGS = 0
VDS = 24V, VGS = 0, TJ = 100°C
VGS = ± 20V
20
VGS = 5V, ID = 15A, VDS = 16V
13
17
VGS = 5V, VDS < 100mV
3.7
–––
nC
VDS = 16V, ID = 15A
VDS = 16V, VGS = 0
Ω
VDD = 16V, ID = 15A
ns
VGS = 5.0V
Clamped Inductive Load
See Test Diagram Fig. 14
VDS = 25V
pF
VGS = 0
Source-Drain Rating & Characteristics
Parameter
Diode Forward Voltage*
Reverse Recovery Charge
Reverse Recovery Charge
(with Parallel Schottsky)
f
f
Symbol
Min Typ Max Units
VSD
–––
–––
1.0
Qrr
–––
76
–––
Qrr(s)
–––
67
–––
V
d
Conditions
IS = 15A , VGS = 0V
di/dt = 700A/µs
VDD = 16V, VGS = 0V, IS = 15A
nC
di/dt = 700A/µs
(with 10BQ040)
VDD = 16V, VGS = 0V, IS = 15A
Notes:
Repetitive rating; pulse width limited by max. junction temperature.
Calculated continuous current based on maximum allowable
Pulse width ≤ 300 µs; duty cycle ≤ 2%.
Junction temperature; switching and other losses will
When mounted on 1 inch square copper board, t < 10 sec.
decrease RMS current capability; package limitation
current = 20A.
Typ = measured - Q
oss
Rθ is measured at TJ approximately at 90°C
*Devices are 100% tested to these parameters.
2
www.irf.com
IRLR8503
Power MOSFET Optimization for DC-DC Converters
While the IRLR8103V and IRLR8503 can and are being used in a variety of applications, they were designed
and optimized for low voltage DC-DC conversion in a
synchronous buck converter topology, specifically, microprocessor power applications. The IRLR8503 (Figure 1) was optimized for the control FET socket, while
the IRLR8103V was optimized for the synchronous
FET function.
IRLR8503
(Cont FET)
Table 2 – New Charge Parameters
New Charge
Parameter
Description
QGS1
Pre-Threshold Gate Charge
Waveform
QGS2
Post-Threshold Gate Charge
Q GCONT
Control FET Total QG
Figure 3
QSWITCH
Charge during control FET switching
Combines QGS2 and QGD
Q OSS
Output charge
Charge supplied to COSS during the QGD
period of control FET switching
Figure 5
Figure 6
QGSYNC
Synchronous FET Total QG (VDS ≤ 0)
Figure 4
Drain Voltage
CGD
Drain Voltage
CGS
IRLR8103V
(Sync FET)
QSwitch
QGD
Figure 2 – Inter-electrode
Capacitance
Because of the inter-electrode capacitance (Figure 2)
of the Power MOSFET, specifying the RDSON of the device is not enough to ensure good performance. An
optimization between RDSON and charge must be performed to insure the best performing MOSFET for a
given application. Both die size and device architecture must be varied to achieve the minimum possible
in-circuit losses. This is independently true for both
control FET and synchronous FET. Unfortunately, the
capacitances of a FET are non-linear and voltage dependent. Therefore, it is inconvenient to specify and
use them effectively in switching power supply power
loss estimations. This was well understood years ago
and resulted in changing the emphasis from capacitance to gate charge on Power MOSFET data sheets.
Table 1 – Traditional Charge Parameters
Device Capacitance
Corresponding Charge Parameter
C GS
QGS
CGS + CGD
QG
CGD
QGD
International Rectifier has recently taken the industry
a step further by specifying new charge parameters
that are even more specific to DC-DC converter design (Table 2). In order to understand these parameters,
it is best to start with the in-circuit waveforms in Figure 3 & Figure 4.
0V
Gate Voltage
QGS1
QGS2
VGTH
Figure 1 – Application
Topology
www.irf.com
QG
(Control FET)
CDS
Dead
Time
Gate Voltage
VGTH
QG (Sync FET)
0A
Drain Current
Figure 3 – Control FET
Waveform
Body
Diode
Current
Drain Current
Figure 4 – Sync FET
Waveform
The waveforms are broken into segments corresponding to charge parameters. These, in turn, correspond
to discrete time segments of the switching waveform.
VIN
g1
N1
Cont FET
Coss1
2n
SN
g2
N2
Sync FET
Coss2
2n
Figure 5 – QOSS
Equivalent Circuit
Switch node voltage
(VSN)
N1 Gate
Voltage
N1 Current
N1 Coss Discharge
+
N2 Coss Charge
Figure 6 – QOSS
Waveforms
Losses may be broken into four categories: conduction loss, gate drive loss, switching loss, and output
loss. The following simplified power loss equation is
true for both MOSFETs in a synchronous buck converter:
PLOSS = PCONDUCTION + PGATE DRIVE + PSWITCH + POUTPUT
For the synchronous FET, the PSWITCH term becomes
virtually zero and is ignored.
3
IRLR8503
Table 3 and Table 4 describes the event during the various charge segments and shows an approximation of losses during that
period.
Table 3 – Control FET Losses
Description
Segment Losses
2
Conduction Losses associated with MOSFET on time. IRMS is a function of load
P COND = I RMS × R DS (on )
current and duty cycle.
Loss
Gate Drive Losses associated with charging and discharging the gate of the
PIN = VG × QG × ƒ
MOSFET every cycle. Use the control FET QG.
Loss
Switching Losses during the drain voltage and drain current transitions for every full cycle.
Q GS 2
׃
Losses occur during the QGS2 and QGD time period and can be simplified by using PQGS 2 ≈ VIN × IL ×
Loss
IG
Qswitch.
Q
PQGD ≈ VIN × IL × GD × ƒ
IG
PSWITCH ≈ VIN × IL
Output
Loss
Q SW
׃
IG
Losses associated with the QOSS of the device every cycle when the control
Q
FET turns on. Losses are caused by both FETs, but are dissipated by the control POUTPUT = OSS × VIN × F
2
FET.
Table 4 – Synchronous FET Losses
Conduction
Loss
Gate Drive
Loss
Switching
Loss
Output
Loss
Description
Losses associated with MOSFET on time. IRMS is a function of load current and
duty cycle.
Losses associated with charging and discharging the gate of the MOSFET every
cycle. Use the Sync FET QG.
Generally small enough to ignore except at light loads when the current reverses
in the output inductor. Under these conditions various light load power saving
techniques are employed by the control IC to maintain switching losses to a
negligible level.
Segment Losses
2
PCOND = IRMS × RDSon
PIN = VG × QG × ƒ
PSWITCH ≈ 0
Losses associated with the QOSS of the device every cycle when the control FET
Q
turns on. They are caused by the synchronous FET, but are dissipated in the control POUTPUT = OSS × VIN × ƒ
2
FET.
Typical PC Application
The IRLR8103V and the IRLR8503 are suitable for
Synchronous Buck DC-DC Converters, and are optimized
for use in next generation CPU applications. The
IRLR8103V is primarily optimized for use as the low side
synchronous FET (Q2) with low RDS(on) and high CdV/dt
immunity.The IRLR8503 is primarily optimized for use as
the high side control FET (Q2) with low cobmined Qsw and
RDS(on) , but can also be used as a synchronous FET. The
IRLR8503 is also tested for Cdv/dt immunity, critical for
the low side socket. The typical configuration in which
these devices may be used in shown in Figure 7.
IRLR8503
Control FET (Q1)
1 x IRLR8103Vor
or 2 x IRLR8503
Synchronous
FET (Q2)
Figure 7. 2 & 3-FET solution for
Synchronous Buck Topology.
4
www.irf.com
IRLR8503
Typical Characteristics
IRLR8503
6.0
ID = 15A
ID = 15A
VGS, Gate-to-Source Voltage (V)
VGS = 4.5V
2.0
(Normalized)
RDS(on) , Drain-to-Source On Resistance
2.5
1.5
1.0
VDS = 20V
4.0
2.0
0.0
0.5
-60 -40 -20
0
20
40
60
0
80 100 120 140 160
4
12
16
Figure 9. Gate-to-Source Voltage vs. Typical Gate
Charge
Figure 8. Normalized On-Resistance vs. Temperature
0.015
2500
0.014
VGS
Ciss
Crss
Coss
2000
C, Capacitance (pF)
RDS(on) , Drain-to -Source On Resistance (Ω)
8
QG, Total Gate Charge (nC)
T J , Junction Temperature ( °C )
0.013
0.012
ID = 15A
=
=
=
=
0V,
f = 1MHz
Cgs + Cgd , Cds SHORTED
Cgd
Cds + Cgd
Ciss
1500
1000
0.011
Coss
500
0.010
0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0 11.0 12.0
Crss
1
VGS, Gate -to -Source Voltage (V)
100
Figure 11. Typical Capacitance vs. Drain-to-Source Voltage
Figure 10. Typical Rds(on) vs. Gate-to-Source Voltage
1000.0
ID, Drain-to-Source Current (Α)
100
10
V DS , Drain-to-Source Voltage (V)
100.0
T J = 150°C
10.0
T J = 25°C
VDS = 15V
20µs PULSE WIDTH
1.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
VGS, Gate-to-Source Voltage (V)
Figure 12. Typical Transfer Characteristics
www.irf.com
5
IRLR8503
Thermal Response (Z thJC )
10
1 D = 0.50
0.20
0.10
PDM
0.05
0.1
0.02
0.01
0.01
0.00001
t1
SINGLE PULSE
(THERMAL RESPONSE)
t2
Notes:
1. Duty factor D = t 1 / t 2
2. Peak TJ = P DM x ZthJC + TC
0.0001
0.001
0.01
0.1
1
t1 , Rectangular Pulse Duration (sec)
Figure 13. Maximum Effective Transient Thermal Impedance, Junction-to-Ambient
Inductive Load Circuit
Figure 15. Switching waveform
Figure 14. Clamped Inductive Load test diagram
6
www.irf.com
IRLR8503
D-Pak (TO-252AA) Package Outline
Dimensions are shown in millimeters (inches)
2.38 (.094)
2.19 (.086)
6.73 (.265)
6.35 (.250)
1.14 (.045)
0.89 (.035)
-A1.27 (.050)
0.88 (.035)
5.46 (.215)
5.21 (.205)
0.58 (.023)
0.46 (.018)
4
6.45 (.245)
5.68 (.224)
6.22 (.245)
5.97 (.235)
1.02 (.040)
1.64 (.025)
1
2
10.42 (.410)
9.40 (.370)
3
LEAD ASSIGNMENTS
1 - GATE
0.51 (.020)
MIN.
-B1.52 (.060)
1.15 (.045)
3X
2X
1.14 (.045)
0.76 (.030)
0.89 (.035)
0.64 (.025)
0.25 (.010)
2 - DRAIN
3 - SOURCE
4 - DRAIN
0.58 (.023)
0.46 (.018)
M A M B
NOTES:
1 DIMENSIONING & TOLERANCING PER ANSI Y14.5M, 1982.
2.28 (.090)
2 CONTROLLING DIMENSION : INCH.
3 CONFORMS TO JEDEC OUTLINE TO-252AA.
4.57 (.180)
4 DIMENSIONS SHOWN ARE BEFORE SOLDER DIP,
SOLDER DIP MAX. +0.16 (.006).
D-Pak (TO-252AA) Part Marking Information
EXAMPLE: T HIS IS AN IRFR120
WIT H AS S EMBLY
LOT CODE 1234
AS S EMBLED ON WW 16, 1999
IN T HE AS S EMBLY LINE "A"
N ote: "P" in as sembly line
pos ition indicates "Lead-Free"
OR
INT ERNAT IONAL
RECT IFIER
LOGO
PART NUMBER
IRFR120
12
AS S EMBLY
LOT CODE
INT ERNAT IONAL
RECT IFIER
LOGO
AS S EMBLY
LOT CODE
DAT E CODE
YEAR 9 = 1999
WEEK 16
LINE A
PART NUMBER
IRFR120
12
www.irf.com
916A
34
P916A
34
DAT E CODE
P = DES IGNAT ES LEAD-FREE
PRODUCT (OPT IONAL)
YEAR 9 = 1999
WEEK 16
A = AS S EMBLY S IT E CODE
7
IRLR8503
Tape & Reel Information
TO-252AA
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.
Data and specifications subject to change without notice.
This product has been designed and qualified for the commercial 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. 5/05
8
www.irf.com
Note: For the most current drawings please refer to the IR website at:
http://www.irf.com/package/