International Rectifier 233 Kansas Street
,
El Se
g
undo
,
CA 90245 USA
R
R
E
EF
FE
ER
RE
EN
NC
CE
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D
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SI
IG
GN
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IRDCiP2021C-1
IRDCiP2021C-1: 500kHz, 40A, Single Output,
Dual Phase Synchronous Buck Converter
Featuring iP2021C and IR3623M
Overview
This reference design is capable of delivering a continuous current of 40A,
single output without heatsink at an ambient temperature of 45ºC and airflow of
200LFM. Fig. 4 – Fig. 16 provide performance graphs, thermal images, and
waveforms. Fig. 1 – Fig. 3 are provided to engineers as design references for
implementing an IR3623+iP2021C solution.
The components installed on this demoboard were selected based on operation
at an input voltage of 12V (+/-10%), a switching frequency of 500kHz (+/-
15%), and an output voltage of 1.2V. Major changes from these set points may
require optimizing the control loop and/or adjusting the values of input/output
filters in order to meet the user’s specific application requirements. Refer to iP2021C and IR3623 datasheets for more
information.
IRDCiP2021C-1 Recommended Operating Conditions
(refer to the iP2021C datasheet for maximum operating conditions)
Input voltage: 8.5V – 14.5V
Output voltage: 0.8 – 5V
Switching Freq: 500kHz
Output current: This reference design is capable of delivering a continuous current of 40A without heatsink at an
ambient temperature of 45ºC and airflow of 200LFM.
Demoboard Quic k Star t Guide
Initial Settings:
VOUT is set to 1.2V, but can be adjusted from 0.8V to 5V by changing the values of R11 and R15 according to the following
formula: R11 = R15 = (10k * 0.8) / (VOUT - 0.8)
The switching frequency is set to 500kHz, but can be adjusted by changing the value of R26. See Fig. 4 for the relationship
between R26 and the switching frequency.
8/13/2009
IRDCiP2021C-1
Power Up Procedure:
1. Apply input voltage across VIN and PGND.
2. Apply load across VOUT pads and PGND pads.
3. Toggle the SEQ (SW1) and EN (SW2) switches to the ON position.
4. Adjust load to desired level. See recommendations above.
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IRDCiP2021C-1
3 www.irf.com
Demoboard Schematic
Fig. 1 Schematic
123456
A
B
C
D
6
54321
D
C
B
A
1
Internatio nal Rectifier
233 Kan s as S t.
iPOWIR Group
El S egundo
CA 902451
B
22-Jul-2009 12:38:39
iP 202 1 & IR 3 623 M Eval - Single Ou tput
Title
Size: Number:
Date: Revision:
Sheet of
:
Time:
Tabloid
C15
100uF C17
10uF
L1
0.22uH
L2
0.22uH
R17
3.65K
R18
3.65K
C1
10uF 16V C2
10uF 16V C5
10u F 16V C6
10u F 16V
C3
10u F 16V C7
10u F 16V
T5
PGND
T3
VOUT1
T1
VIN
TP3
+VOUTS1
TP4
-VOUTS1
C4
10uF 16V C8
10u F 16V
R22
open
C16
100uF C18
10uF
C14
680uF T2
PGND
TP1
+VINS1
TP2 VIN
C19
100uF
C20
100uF
C21
10uF
B1
BOARD
C54
1uF
T6
PGND
T4
VOUT2
TP5
+VOUTS2
TP6
-VOUTS2
C24
open
R12 open
R10 open
R16
0
R6
open
R26
78. 7K (5 00 k Hz )
R14 open
C36
open
C42
open
C34
open
C33
0.1uF
TP23
SYNC
C31
1uF
C32
100pF
R8 open
C38
open
C40
open
R11 20K
R9 10K
R15
20K
R5
11K
R13 10K
C35
5.6pF
C41
100pF
R7 200
C37
2700pF
C39
390pF
C23
open C25
open
C26
open
C22
10uF
1.2V
1.2V
R4
0
R21
open
R19
0
R20
open
PGOOD1
1
VREF
27
COMP1 18
Ph_En1 15
RT
30
SYNC
23
SS1
17
SS2
8
PWM1 14
VP1
25
TRACK1
22
VSEN1 21
SEQ
24
OCSET1 16
ENABLE
31
VCC
12
5V_SNS 32
FB1 19
VOUT3 13
TRACK2
3
PGND
29
GND
28
PGOOD2
2
VP2
26
COMP2 7
Ph_En2 10
PWM2 11
VSEN2 4
OCSET2 9
FB2 6
OCGnd
20
FAULT
5
PGND
0
U3
IRU3623M
TP18
TRACK2
TP17
TRACK1
TP24
FAULT
C28
open C30
open
R1
10K
R2
10K
R3
0
R25
30.1K
R23
10K R24
10K
TP15
PGOOD1
TP16
PGOOD2
C27
open C29
open
TRK2
TRK1
SEQ
SYNC
PGD1
PGD2
VREF
EN
SS1
SS2
RT
FLT
FB1
FB2
VSEN1
CC1
CC2
OC1
OC2
EN1
EN2
PWM1
PWM2
VSW1
VSW2
VSEN2
VIN
VOUT3
VOUT3
VOUT1
VOUT1
VOUT2
VIN
VOUT3
VOUT3
C13
0.1uF C43
1uF
R28 0
R33
10K
VOUT3
R35
0
R27 0
R34
10K
PH_EN1
PH_EN2
C51
100pF
C52
100pF
R36
open
VP2
R45
open
R29
1.62K C49
0.47uF
R39
0VP2
R30
1.62K C50
0.47uF
R40
0FB2
R46
9.31K C57
1000pF
R47
open
R44
0
R43
0
R42
0
R41
0
VOUT1
VOUT2
C45
1uF
C53
1uF
R31 0
R32 0
PWM1_IC
VCC
VDD
VDD
PWM2_IC
TP10
EN2
TP12
PWM2
TP9
EN1
TP11
PWM1
TP21
VSW1
TP22
VSW2
TP13
SS1
TP14
SS2
TP7
VDD
TP8
PGND
TP19
CC1
TP20
CC2
TP25
FB1
TP26
FB2
TP27
+VINS2
TP28
PGND
C55
open
C56
open
SW1
EN SW2
SEQ
TP29
VO1A
TP30
VO1B
TP31
VO2A
TP32
VO2B
TP35
VOUT1
TP33
PGND
TP36
VOUT2
TP34
PGND
TP37
PGND TP38
PGND
VOS1-
VOS2-
-VOUTS1 -VOUTS2
T7
PGND
T9
PGND
VIN 12
ENA1
11
PWM1
5
CVCC 4
VIN1 1
VIN2 9
PGND
7
VSW1 2
ENA2
10
PWM2
6
PGND
3
VSW2 8
U1
iP2021
OC1
VIN
C9
10u F 16V C10
10uF 16V C11
10uF 16V C12
10uF 16V
12
C44
open
12
C46
220uF
12
C47
open
12
C48
open
VOUT1
12
C58
open
12
C59
220uF
12
C60
open
12
C61
open
VOUT2
R37
open
R38
0
R48
open
R49
0
VOS1+
VOS1D+
VOS1D-
VOS1S+
VOS1S-
C62
1uF
59. 0K (6 00 k Hz )
16. 2K (1 MHz)
IRDCiP2021C-1
Bill of Material
g
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alu e 2 T o lerance Packa
V
alue 1
y
pe 2
y
pe 1 Tnator T
g
DesiQuantit
y
e Manu fac 1 Manu fac 1No
16 C1, C2, C3, C4, C5, C6 , C7, C8, C9, C10 ,
C11, C12, C17 , C18 , C21, C22 capacitor X7R 10.0uF 16V 10% 1206 TDK C3216X7R1C106KT
2 C13, C33 capacitor X7R 0.100uF 50V 10% 0603 TDK C1608X7R1H104K
1 C14 capacitor electrolytic 680uF 16V 20% SMD Panasonic EEV-FK1C681GP
4 C15, C16, C19 , C20 capacitor X5R 100uF 6.3V 20% 1210 TDK C3225X5R0J 107M
6 C31, C43, C45 , C53 , C54, C62 capaci tor X7R 1.00uF 16V 10% 0603 TDK C1608X7R1C105KT
4 C32, C41, C51 , C52 capacitor NPO 100pF 50V 5% 0603 Phycomp 0603CG101J9B20
1 C35 capacitor NPO 5.60pF 50V +/-0.50pF 0603 KOA NPO0603HTTD5R6D
1 C37 capacitor X7R 2700pF 50V 10% 0603 KOA X7R0603HTTD272K
1 C39 capacitor NPO 390pF 50V 5% 0603 KOA NPO0603HTTD391J
2 C46, C59 capacitor tantalum polymer 220uF 2.5V 20% 7343 Sanyo 2R5TPC220M
2 C49, C50 capacitor X7R 0.470uF 16V 10% 0603 TDK C1608X7R1C474KT
1 C57 capacitor X7R 1000pF 50V 10% 0603 BC Component 0603B102K500NT
2 L1, L2 inductor f errit e 0.22uH 47 A 10% SMT Vi t ec 59PR9873N
8 R1 , R2, R9, R13, R2 3, R24 , R33, R34 resistor thick film 10.0K 1/10W 1% 0603 KO A RK 73H1 J 1002F
2 R11, R15 resistor thick fil m 20.0K 1/10W 1% 0603 KO A RK 73H1 J20 02F
11 R3, R4, R16, R27, R28, R31, R32, R38,
R39, R40, R49 resistor thick film 0 1/10W 1% 0603 KOA RK73Z1 JLTD
2 R17, R18 resistor thick fil m 3.65K 1/10W 1% 0603 KO A RK73H1JLTD3651F
1 R19 resistor thick film 0 1/8W <50m 0805 ROHM MCR10EZHJ000
1 R25 resistor thick film 30.1K 1/10W 1% 0603 KOA RK73H1J3012F
1 R26 resistor thick film 78.7K 1/10W 1% 0603 KOA R K 73H1JLTD7872F
2 R29, R30 resistor thick fil m 1.62K 1/10W 1% 0603 KO A RK73H1JLTD1621F
1 R35 resistor thick film 0 1/8W <50m 1206 Panasonic ERJ- 8GEY0R00
4 R41, R42, R43 , R44 resistor m anganin-foil 0 2W n/a 2817 Isotek Corp SMT - R000
1 R46 resistor thick film 9.31K 1/10W 1% 0603 KOA R K73H1JLTD9 311F
1 R5 resistor thick film 11.0K 1/10W 1% 0603 KOA R K73H1JLTD1 102F
1 R7 resistor thick film 200 1/10W 1% 0603 KOA RK73H1J2000F
2 SW1, SW2 switch sli d e SPDT 30VDC 0.2A pcb mo unt E-Switch E G1218
18 TP1, TP2, TP3, TP4, TP5, TP6, TP7, TP8,
TP27, TP28, TP29, TP30, TP31, TP32,
TP33, TP34, TP35, TP36 hardware test point 90 mil s 112 x 150 mils - 5016 Ke y st one 5016
20
TP9, TP10, TP11, TP12, TP13, TP14,
TP15, TP16, TP17, TP18, TP19, TP20,
TP21, TP22, TP23, TP24, TP25, TP26,
TP37, TP38
hardware test poi nt 60 mils 40 x 105 mils - 5015 Keystone 5015
1 U1 iP 2021 LGA uni t rev a - - 7. 6 5mm x 11m m IRF rev a
1 U3 IC analog PWM c ont r oller -0.5 - 16V -0.5 - 16V -40 - 120° C MLPQ-32L IR F IR3623M
www.irf.com 4
IRDCiP2021C-1
Demoboard Component Placement
Fig. 2
Top Layer (Face View)
Fig. 3
Bottom Layer (Through View)
5 www.irf.com
IRDCiP2021C-1
Description of Test Points and Connectors
1.
Jumpers
Jumper Pin Name Description
SW1 EN Board Enable ( switch Up = On ) - Vin pin on top Off, Down =
SW2 SEQ Sequence ( switch Up = Off, Down = On ) - Vin pin on top
2. Points ctors
Test /Conne
Test Point Pin Name Description
T1 / T2 VIN / P Vin supply voltage GND
T ense P2 / TP28 VIN / PGND Vin supply voltage s
T3 / T5 / T7 VOUT1 / PGND / PGND to DC load Channel 1 Output, connect
TP35 / TP33 VOUT1 / PGND Channel 1 Output sense
TP21 / TP37 VSW1 / PGND Channel 1 switch node / PGND test points
TP9 EN1 Channel 1 Enable test po int
TP11 PWM1 Channel 1 PWM test point
TP19 CC1 Channel 1 error amplifier output
TP25 FB1 Channel 1 error amplifier non-inverting input
T4 T2 / PGND / PGND / T6 / T9 VOU Channel 2 Output, connect to DC load
TP36 / TP34 VOUT2 / PGND Channel 2 Output sense
TP22 / TP38 VSW2 / PGND Channel 2 switch node / PGND test points
TP10 EN2 Channel 2 Enable test point
TP12 PWM2 Channel 2 PWM test point
TP20 CC2 Channel 2 error amplifier output
TP26 FB2 Channel 2 error amplifier non-inverting input
TP7 / TP8 / PGND le VDD Supply voltage for IRU3623 and iPOWIR modu
TP23 SYNC External frequenc y synchronization input
TP17 TRACK1 if not used Channel 1 tracking input, pull-up to Vout3
TP18 TRACK2 Track2 test point
TP15 PGOOD1 Channel 1 Power good test point
TP16 PGOOD2 Channel 2 Power good test point
TP13 SS1 Channel 1 Soft start test point
TP14 SS2 Channel 2 Soft start test point
TP24 FAULT Fault monitor test point
3. points ement
Test for Efficiency Measur
Test Point Pin Name Description
TP1 / TP4 +VINS 1 Channel 1 Vin sense for eff rement 1 / -VOUTS iciency measu
TP3 / TP4 +VOUTS1 / -VOUTS1 nt Channel 1 Output sense for efficiency measureme
TP27 / TP6 +VINS2 / -VOUTS2 Channel 2 Vin sense for efficiency measurement
TP5 / TP6 +VOUTS2 / -VOUTS2 nt Channel 2 Output sense for efficiency measureme
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IRDCiP2021C-1
Test Results
Fig. 4 Relationship Between Switching Frequency and R2
6
Fig. 5 Power Up Sequence (C3: EN, C1: SS1, C4: VOUT)
Fig. 6 Power Down Sequence (C3: EN, C1: SS1, C4: VOUT)
VIN = 12V, VOUT = 1.2V, Iout = 40A, fsw = 500 kHz
VIN = 12V, VOUT = 1.2V, Iout = 40A, fsw = 500 kHz
7 www.irf.com
IRDCiP2021C-1
g. 7 Hiccup Mode Over Current Protection (C1: SS1, C4: Iout, C3: VOUT)
VIN = 12V, VOUT = 1.2V, fsw = 500 kHz
Fi
Fi
g. 8 Hiccup Mode Over Current Protection (C1: SS1, C4: Iout, C3: VOUT)
VIN = 12V, VOUT = 1.2V, fsw = 500 kHz
Fig. 9 Deadtime and Ri n gin g on Switch Node
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IRDCiP2021C-1
Fig. 2)
Fig. 10 Output Vol t age DC Ripple
Vp-p = 20 mV
out sw
Fig. 11 Output Vol t age DC Ripple
12 Load Transient Response (C1: VOUT – AC, C2: Iout divided by
VIN = 12V, VOUT = 1.2V, I = 20A, f = 500 kHz
VIN = 12V, VOUT = 1.2V, Iout = 20A, fsw = 500 kHz
VIN = 12V, VOUT = 1.2V, Iout = 0-40A, 0 . 5A/µs,
Hfsw = 500 k z
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IRDCiP2021C-1
Fig. 13 Bode Plot (VIN = 12V, VOUT = 1.2V, Iout = 20A)
Current Sharing Accuracy
The accuracy of current sharing is tested by measuring the DC voltage across the two inductors at the following
operating condition s : VIN = 12V; VOUT = 1.2V; Iout = 10 – 40A. The test re sults are shown below:
Table 1 Inductor DC V olt a ge s at Dif fere nt C ur rents for Single Output Con fi g urat i o n
Iout (A) VL1 (mV) VL2 (mV)
fc = 65 kHz
PM = 49
10 1.5 1.9
20 3.4 3.8
30 5.5 5.8
40 7.5 7.9
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IRDCiP2021C-1
VIN = 12V, V OUT = 1.2V, 200LFM, fsw = 500kHz, No Heatsi nk
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
0 5 10 15 20 25 30 35 40
Load Current (A)
Power Loss (W)
45C
Room Tem perat ure
Fig. 14 Power Loss
VIN = 12V, V OUT = 1.2V, 200LFM, fsw = 500kHz, No Heatsi nk
72%
74%
76%
78%
80%
82%
84%
86%
88%
90%
92%
0 5 10 15 20 25 30 35 40
Load Current (A)
Efficiency
45C
Room Tem perat ure
Fig. 15 Efficiency
11 www.irf.com
IRDCiP2021C-1
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IRDCiP2021C-1
www.irf.com 12
Fig. 16 Thermal Image: Iout = 40A, VIN = 12V, VOUT = 1.2V, TA = 45oC, fsw = 500kHz, 200LFM, No Heatsink,
Maximum IC Temperature = 94.2 oC
Refer to the following application notes for detailed guidelines and suggestions when
implementing iPOWIR Technology products:
AN-1043: Stabilize the Buck Converter with Transconductance Amplifier
This paper explains how to design the voltage compensation network for Buck Converters with
Transconductance Amplifier. The design methods and equations for Type II and Type III compensation
are given.
AN-1028: Recommended Design, Integration and Rework Guidelines for International Rectifier’s
iPowIR Technology BGA and LGA and Packages
This paper discusses optimization of the layout design for mounting iPowIR BGA and LGA packages on
printed circuit boards, accounting for thermal and electrical performance and assembly considerations.
Topics discussed include PCB layout placement, and via interconnect suggestions, as well as soldering,
pick and place, reflow, inspection, cleaning and re working recommendations.
AN-1030: Applyi ng iPOWIR Products in Your Thermal Environment
This paper explains how to use the Power Loss and SOA curves in the data sheet to validate if the
operating conditions and thermal environment are within the Safe Operating Area of the iPOWIR product.
AN-1047: Graphical solution for two b ranch heatsinking Safe Operating Area
Detailed explanation of the dual axis SOA graph and how it is derived.
Use of this design for any application should be fully verified by the customer. Internation l Rectifier
cannot guarantee suitability for your applications, and is not liable for any result of usage for such
applications including, without limitation, erty damage or violation of third party
intellectual property rights.
IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, Calif ornia 90245, USA Tel: (310) 252-7105
TAC Fax: (310) 252-7903
a
personal or prop
