International Rectifier • 233 Kansas Street
,
El Se
g
undo
,
CA 90245 USA
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IRDCiP1206-A
IRDCiP1206-A: 300 kHz, 30A, Synchronous
Buck Converter using iP1206
Overview
This reference design is capable of delivering a continuous
current of 30A (at an ambient temperature of 25ºC and no
airflow. Figures 1–16 provide performance graphs, thermal
images, and waveforms. Figures 17–27, and Table 1 are
provided to engineers as design references for implementing
an iP1206 solution. The components installed on this
demoboard were selected based on operation at an input
voltage of 12V and at a switching frequency of 300 kHz.
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 the iP1206 datasheet User Design Guidelines section
for more information.
Note: The 16-pin connector (CON1) is used only for
production test purposes and should not be used for
evaluation of this demoboard.
Demoboard Quick Start Guide
Initial Settings:
VOUT is set to 1.2V, but can be adjusted from 0.8V to 5.5V by changing the values of R5 and R6 according to the following
formula: R5 = R6 = (10.0k * 0.8) / (VOUT - 0.8)
The switching frequency is set to 300kHz, but can be adjusted by changing the value of R
T
. The graph in Figure 18 shows the
relationship between R
T
and the switching frequency.
Power Up Procedure:
1. Apply input voltage across VIN and PGND.
2. Apply load across VOUT pads and PGND pads.
3. Adjust load to de sired level. See recommendations below.
IRDCiP1206-A Recommended Operating Conditions
(Refer to the iP1206 datasheet for maximum operating conditions)
Input voltage: 7.5V – 14.5V
Output voltage: 0.8 – 5.5V
Switching Freq: 300kHz
Output current: This reference design is capable of delivering a continuous current of 30A (without heatsink) at an
ambient temperature of 45ºC with 200LFM of airflow.
IRDCiP1206-A_______ _____
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0
1
2
3
4
5
6
7
8
9
10
0A 5A 10A 15A 20A 25A 30A
Output Current (A)
Power Loss (W)
1.2V 1.5V 1.8V 2.5V 3.3V
Fig. 1: Power Loss vs.
Output Current
Fig. 2: Efficiency vs.
Output Current
Conditions:
Vin = 12V
Vout = 1.2V to 3.3V
Fsw= 300KHz
Ta = 25O C
No heat sink
No Airflow
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
90.00%
100.00%
0A 5A 10A 15A 20A 25A 30A
Output Current (A)
Efficien cy (%)
1.2V 1.5V 1.8V 2.5V 3.3V
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Fig. 3: Output Voltage Regulation vs. Current
Fig. 4: Bode Plot
The Voltage Regulation is better than 0.35%
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300KHz
No Airflow
Fc = 50 KHz
PM =70 o
GM = 13dB
IRDCiP1206-A_______ _____
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Fig. 5: Thermograph (No Heatsink)
Fig. 6: Power Up Sequence
Conditions:
Vin = 12V
Vout = 1.2V
Iout = 30A
Fsw = 300kHz
Ambient Temp. = 45ºC
Airflow = 200LFM
Stabilizing Time = 15
min
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
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Fig. 7: Power Down Sequence (Turning off a 30A Load)
Fig. 8: Close-up of Power Down when Enable is pulled low
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
IRDCiP1206-A_______ _____
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Fig. 9: Current Share Mode (Switch Node Waveforms)
Fig. 10: Output Voltage Ripple
Peak to Peak Output
Ripple = 13mV
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
_____________ __IRDCiP1206-A
7 www.irf.com
Fig. 11: Short Circuit Protection
Fig. 12: Over-voltage Protection
Short Circuit Current = 62A
Tested at Room Tem perature
ROCSET = 10KΩ
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
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Fig. 13: Iout Transient Step-Up 50% - 75% Fig. 14: Iout Transient Step-Down 75% - 50%
Fig. 15: Iout Transient Step-Up 50% - 100% Fig. 16: Iout Transient Step-Down 100% - 50%
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
Vin = 12V
Vo = 1.2V
Iout = 30A
Fsw = 300kHz
No Airflow
110 mV
105 mV
60 mV
60 mV
_____________ __IRDCiP1206-A
9 www.irf.com
Adjusting the Over-Current Limit
ROCx is the resistor used to adjust the over-current trip point. The trip point corresponds to the peak inductor current indicated o n
the x-axis of Fig. 21. (Note: The trip point will be higher than expected if the reference board is cool and is being used for short
circuit testing.)
Fig. 17: ROCSET vs. Over-Current Trip Point
Fig. 18: RT vs. Frequency
Switching Frequency Vs. Rt
0
100
200
300
400
500
600
700
0 10203040506070
Rt (Kohm )
Fsw (kHz)
1
2
3
4
5
6
7
8
9
10
11
12
13
56789101112131415161718192021222324252627282930
Peak Indu ctor Cur r e nt ( A)
Current Lim it Resistor (kO hm s)
IRDCiP1206-A_______ _____
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Fig. 19: Component Placement Top Lay er Fig. 20: Component Placement Bo ttom Layer
Fig. 21: Top Copper Layer Fig. 22: 1st Mid Copper Lay er
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Fig. 23: 2nd Mid Copper Layer Fig. 24: 3rd Mid Copper Layer
Fig. 25: 4th Mid Copper Layer Fig. 26: Bottom Copper Layer
IRDCiP1206-A_______ _____
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C22
0.1uF
C19
1uF
C5
10uF 16V
C25
100pF
C26
5600pF
R7
4.22K
R13
4.22K
R12
750
R5
20K
R14
30.9k(300kHz)
TP5
SYNC
R8
10K
C24
1500pF
ROC2
5.76K
PGD1
SS1
VREF
VIN
RT
FB1
CC1
FB1S
L2
1.0uH
C9
100uF
C10
100uF
C11
100uF
VOUT
TP1
+12V
C21
0.1uF
SEQ
C6
10u F 16V
C1
10uF 16V
C2
10uF 16V
C3
10u F 16V
C4
10uF 16V
VIN1 16
VIN2 3
VSW1 14
VSW2 5
AGND
36
PGND
4
PGND
6
PGND
13
PGND
15
SS1
17
CC1 18
FB1 19
FB1S 20
SEQ
21
SYNC
22
PGD2
23
VP1
24
VP2
25
VREF
26
PGD1
27
VCC
28
VO3
29
TRK
30
ENABLE
31
DH_ON 32
RT
33 FB2S 34
FB2 35
CC2 1
SS2
2
VCB1 12
OC1 11
VCL 10
VCH 9
OC2 8
VCB2 7
U1
iP1206
C27
100pF
R11
402
C15
8200pF
R9
10K
C29
1.0uF
L1
1.0uH
ROC1
5.76K
R10
402
C23
1.0uF
R6
20K
C20
100pF
FB2
OC1
OC2
SS2
PGD2
R4
100K
VO3
EN
CC2
VP2
SYNC
VCB1
C28
0.1uF
VCB2
VSW1
VSW2
VP2
C16
1uF
C17
1uF
C18
0.1uF
FB1S
C12
100uF
1.2V
C13
10uF
C14
10uF
TP6
1.2V_EN
R3
100K
R1
100K
TP3
+1.2V
R17
0
R15
0
R16
0
C30
680uF
J1
VIN
J2
PGND
VIN
J3
VOUT
J4
PGND
1
3
5
7
9
11
13
15
2
4
6
8
10
12
14
16
CON1
SMT16_CONNECTOR
VINS
PGNDS
VSW1
VSW2
VOUT SS1
C7
10uF 16V
C8
10uF 16V
R18
0
VCC
R2
0
VCC_VIN
R20
1.43K
R19
10K
TP7
SS1
TP8
PGD1
TP2
PGND
TP4
PGND
R22
open
R21
0
VCH
C31
330uF
C32
330uF
C33
330uF
C34
330uF
(no stuff) (no stuff)(no stuff)(no stuff) (no stuff)
Fig. 27. Reference Design Circuit Schematic
_____________ __IRDCiP1206-A
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Quantit
y
Desi
g
nator T
y
pe 1 T
y
pe 2
V
alue 1
V
alue 2 Tolerance Packa
g
e Manufac 1 Manufac 1No
10 C1, C2, C3, C4, C5, C6, C7, C8, C13, C14 capacitor X7R 10.0uF 16V 10% 1206 TDK C3216X7R1C106KT
2C9, C10 capacitor X5R 100uF 6.3V 20% 1210 TDK C3225X5R0J107M
1C15 capacitor X7R 8200pF 50V 10% 0603 KOA X7R0603HTTD822K
3C16, C17, C19 capacitor X7R 1.00uF 16V 10% 0805 MuRata GRM40X7R105K016
4C18, C21, C22, C28 capacitor X7R 0.100uF 16V 10% 0603 MuRata GRM188R71C104KA01D
3C20, C25, C27 capacitor NPO 100pF 50V 5% 0603 Phycomp 0603CG101J9B20
2C23, C29 capacitor X7R 1.00uF 16V 10% 0603 TDK C1608X7R1C105KT
1C24 capacitor X7R 1500pF 50V 10% 0603 KOA X7R0603HTTD152K
1C26 capacitor X7R 5600pF 50V 10% 0603 KOA X7R0603HTTD562K
1C30 capacitor electrolytic 680uF 16V 20% SMD Panasonic EEV-FK1C681GP
1C32 capacitor tantalum polymer 330uF 2.5V 20% 7343 Sanyo 2R5TPE330M9
2L1, L2 inductor ferrite 1.00uH 25A 20% SMT Delta Electronics MP L105-1R0IR
3R1, R3, R4 resistor thick film 100K 1/10W 1% 0603 KOA RK73H1J1003F
2R10, R11 resistor thick film 402 1/10W 1% 0603 KOA RK73H1JLTD4020F
1R12 resistor thick film 750 1/10W 1% 0603 KOA RK73H1JLTD7500F
2R7, R13 resistor thick film 4.22K 1/10W 1% 0603 KOA RK73H1JLTD4221F
1R14 resistor thick film 30.9K 1/10W 1% 0603 KOA RK73H1J3092F
3R15, R16, R17 resistor thick film 0 1/10W 1% 0603 KOA RK73Z1JLTD
3R2, R18, R21 resistor thick film 0 1/8W <50m 0805 ROHM MCR10EZHJ000
3R8, R9, R19 resistor thick film 10.0K 1/10W 1% 0603 KOA RK73H1J1002F
1R20 resistor thick film 1.43K 1/10W 1% 0603 KOA RK73H1JLTD1431F
2R5, R 6 resistor thick film 20.0K 1/10W 1% 0603 KOA RK73H1J2002F
2ROC1, ROC2 resistor thick film 5.76K 1/10W 1% 0603 KOA RK73H1JLTD5761F
81.2V_EN, PGD1, PGNDS, PGNDS, SS1,
SYNC, VINS, VOUTS hardware test point 90 mils 112 x 150 mils - SMT Keystone 5016
1U1 iP1206 LGA unit rev- b - - 9.25 x 15.5mm IRF rev- b
*Red - Top Side Components
*Blue - Bottom Side Components
Table 1: Bill of Materials for the Reference design
IRDCiP1206-A_______ _____
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Refer to the following application notes for detailed guidelines and suggestions when
implementing iPOWIR Technology products:
AN-1028: Recommended Design, Inte gration 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 a ssembly considerations.
Topics discussed includes 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 Po wer 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 branch 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. International Rectifier
cannot guarantee suitability for your a pplications, and is not liable for any result of usage for such
applications including, without limitation, personal or property d amage 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) 252-7 903
