an1521

Application Note 1521
ISL6445 Evaluation Board User Guide
Hardware Description
VIN
The ISL6445EVAL3Z evaluation board is designed to
demonstrate the performance of the ISL6445.
LOAD
LOAD
The ISL6445 is a high-performance, dual-output PWM
controller optimized for converting wall adapter, battery
or network intermediate bus DC input supplies into the
system supply voltages required for a wide variety of
applications. Each output is adjustable down to 0.8V. The
two PWMs are synchronized 180° out-of-phase reducing
the RMS input current and ripple voltage.
5.6V TO 24V
ISL6445 Reference Design
The ISL6445 evaluation board illustrates the operation of
the IC. The design criteria is listed in Table 1.
FIGURE 1. POWER AND LOAD CONNECTIONS FOR
5.6V TO 24V INPUT VOLTAGE
TABLE 1. DESIGN CRITERIA
3.3V
Output current (IOUT1)
3A
Output voltage (VOUT2)
2.5V
Output current (IOUT2)
3A
Power and Load Connections
If using an input supply ranging from 5.6V to 24V,
connect the supply to VIN (P1) and GND (P2) posts as
shown in Figure 1. ISL6445 has an internal +5V linear
regulator which can be used to bias the IC.
When using a 5V ±10% input supply, connect the
negative polarity to GND (P2) post and connect the
positive polarity of the power supply to both VIN (P1)
post and the VCC5 (TP1) post. This will disable the
internal LDO and the chip will be powered by the input
power supply (see Figure 2).
CAUTION: Ensure that the +5V terminal is not
connected to when applying voltages >7V. This
can damage the IC.
1
LOAD
Output voltage (VOUT1)
January 15, 2010
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VIN
5V±10%
PACKAGE
LOAD
PARAMETERS
FIGURE 2. POWER AND LOAD CONNECTIONS FOR
5V±10% INPUT VOLTAGE
Test-point and Terminals Descriptions
TABLE 2. ISL6445EVAL3Z TEST POINT DESCRIPTION
TEST POINTS
AND TERMINALS
SIGNALS
TP1
PGOOD
TP2
VCC5
TP3
GND
P1
VIN
P2
GND
P3
VOUT2
P4
GND
P5
VOUT1
P6
GND
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2010. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
Application Note 1521
Typical Performance Curves
95
95
VIN = 12V
90
90
VIN = 12V
85
80
VIN = 18V
75
VIN = 24V
70
65
60
55
50
EFFICIENCY (%)
EFFICIENCY (%)
85
80
75
VIN = 18V
70
65
60
55
50
45
45
40
40 0.3
0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0
OUTPUT CURRENT (A)
1.2
1.5
1.8
2.1
2.4
2.7
3.0
2.505
3.300
VIN = 12V
VIN = 18V
VIN = 24V
OUTPU VOTLAGE (V)
3.305
3.290
0.9
FIGURE 4. EFFICIENCY FOR VOUT2 (VOUT1 IS
DISABLED)
3.310
3.295
0.6
OUTPUT CURRENT (A)
FIGURE 3. EFFICIENCY FOR VOUT1 (VOUT2 IS
DISABLED)
OUTPU VOTLAGE (V)
VIN = 24V
2.500
2.495
2.490
VIN = 18V
2.485
0.0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0
OUTPUT CURRENT (A)
FIGURE 5. VOUT1 (3.3V) REGULATION
VIN = 12V
VIN = 24V
0.0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0
OUTPUT CURRENT (A)
FIGURE 6. VOUT2 (2.5V) REGULATION
VOUT1
VOUT1
VOUT2
VOUT2
PGOOD
FIGURE 7. OUTPUT RIPPLEs AT FULL LOAD (20BW);
INPUT VOLTAGE = 12V
2
FIGURE 8. SOFT-START WAVEFORMS
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Application Note 1521
VOUT1
VOUT1
VOUT2
VOUT2
IOUT1
IOUT2
FIGURE 9. LOAD TRANSIENT:
INPUT VOLTAGE = 12V,
IOUT1 = 0A <-> 3A, IOUT2 = 3A
FIGURE 10. LOAD TRANSIENT:
INPUT VOLTAGE = 12V,
IOUT1 = 3A, IOUT2 =0A <->3A
VOUT1
VOUT1
VOUT2
VOUT2
IOUT1
IOUT2
FIGURE 11. LOAD TRANSIENT:
INPUT VOLTAGE = 18V,
IOUT1 = 0A <-> 3A, IOUT2 = 3A
FIGURE 12. LOAD TRANSIENT:
INPUT VOLTAGE = 18V, IOUT1 = 3A,
IOUT2 =0A <->3A
VOUT1
VOUT1
VOUT2
VOUT2
IOUT1
IOUT2
FIGURE 13. LOAD TRANSIENT:
INPUT VOLTAGE = 24V,
IOUT1 = 0A <-> 3A, IOUT2 = 3
3
FIGURE 14. LOAD TRANSIENT:
INPUT VOLTAGE = 24V,
IOUT1 = 3A, IOUT2 =0A <->3A
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January 15, 2010
ISL6445EVAL3Z Schematic
P1
1
VIN
1
VIN
C20
10uF
2
TP3
P2
1
GND
1
Q1
1
1
JP2
C27
DNP
1
SS2 9
0.1uF
OCSET2 10
R13 60.4k
11
2
C25
2
R18
12
ISEN2
PGOOD
VCC5
SD2
SS2
OCSET2
PGND
SD1
SS1
SGND
OCSET1
FB2
FB1
VIN
BIAS
TP1
1 PGOOD
R2
R3
806
18
17 SS1
1
0.1uF
15 OCSET1
R4
14
60.4k
1k
R14
JP1
R16
0
13
PGOOD
11.5k
C28
1uF
2
C15
2.2uF
C2
270pF
R15
10k
1
C23
1uF
1
GND
35.7k
C26
DNP
C5
10uF
P6
R17
2
C10
16
C1
330pF
VOUT1
C6
1uF
2
0
0
20 ISEN1
19
1
2
R11
2
0.1uF
1
C7
PHASE1 R8
C16
220uF
2.2
2
21
1
1
ISEN1
22 UGATE1
R12
2
PHASE1
0
2
2
R20
PHASE2
VIN
0
11.5k
2
C14
330pF
UGATE1
R7
1
8
2
24.3k
C4
270pF
DNP
C13
7
BOOT1
UGATE2
LGATE1
23 BOOT1 1
P5
VOUT1 1
2
VCC5
1
R19
2
R21
1k
1
2
1
4.7uF
PGOOD 6
Vout=3.3V @3A
2
1
2
C21
806
BOOT2
24
1
2.2
1 2
GND
C24
1uF
PHASE2 4
ISEN2 5
R1
2
1
2
P4
0
LGATE1
1
1
2
R5
C17
220uF
C8
10uF
C22 0.1uF
UGATE2 3
R10
ISL6445IAZ
2
1
1
2
1
C9
1uF
0
U1
LGATE2
L1
1.5uH
C3
DNP
Application Note 1521
VOUT2
L2
1.5uH
1BOOT2 2
1
R9
IRF7902PBF
P3
LGATE2 1
1
Vout=2.5V @3A
0
2
1
2
R6
BAT54HT
D1
2
2
2
IRF7902PBF
BAT54HT
D2
C11
1uF
Q2
1
C12
1uF
1
1
2
4
C18
10uF
1VOUT2
2
C19
10uF
VCC5
VIN
1
VIN
TP2
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January 15, 2010
Application Note 1521
ISL6445EVAL3Z Rev. A Bill of Materials
ID REFERENCE QTY PART NUMBER
PART TYPE
DESCRIPTION
PACKAGE
VENDOR
1
U1
1
ISL6445IAZ
Dual PWM Controller
IC, Dual PWM Controller
24 Ld QSOP Intersil
2
Q1, Q2
2
IRF7902PBF
MOSFET, Dual
Dual 30V N-channel MOSFET SO-8
International
Rectifier
3
D1, D2
2
BAT54HT1G-T
Diode, Schottky
30V, 200mA
SOD-323
On Semi
4
L1, L2
2
FP3-1R5-R
Inductor
1.5µH, 20%, 6.2A
SMD
Coiltronics
CAPACITORS
5
C1, C14
2
Capacitor, Ceramic, X7R
330pF, 10%, 50V
SM_0603
Various
6
C2, C4
2
Capacitor, Ceramic, X7R
270pF, 10%, 50V
SM_0603
Various
7
C5, C8
2
Capacitor, Ceramic, X5R
10µF, 10%, 16V
SM_1206
Various
8
C6, C9, C11,
C12, C23,
C24, C28
7
Capacitor, Ceramic, X5R
1µF, 10%, 25V
SM_0603
Various
9
C7, C10,
C22, C25
4
Capacitor, Ceramic, X7R
0.1µF, 10%, 50V
SM_0603
Various
10
C15
1
Capacitor, Ceramic, X5R
2.2µF, 20%, 25V
SM_805
Various
11
C16, C17
2
Capacitor, POSCAP
220µF, 20%, 6.3V, 0.018Ω
Case D2E
SANYO
12
C18, C19,
C20
3
Capacitor, Ceramic, X7R
10µF, 10%, 25V
SM_1210
Various
13
C21
1
Capacitor, Ceramic, X5R
4.7µF, 10%, 16V
SM_0805
Various
14
C3, C13,
C26, C27
6TPE220MI
Do not populate
RESISTORS
15
R1,R3
2
Resistor, Film
806Ω, 1%, 1/10W
SM_0603
Panasonic/Generic
16
R2
1
Resistor, Film
10kΩ, 1%, 1/10W
SM_0603
Panasonic/Generic
17
R4, R13
2
Resistor, Film
60.4kΩ, 1%, 1/16W
SM_0603
Panasonic/Generic
18
R5, R12
2
Resistor, Film
2.2Ω, 1%, 1/10W
SM_0603
Panasonic/Generic
19
R6, R7, R8,
R9, R10, R11,
R16, R18
8
Resistor, Film
0Ω, 1/10W
SM_0603
Panasonic/Generic
20
R14
1
Resistor, Film
35.7kΩ, 1%, 1/10W
SM_0603
Panasonic/Generic
21
R15, R20
2
Resistor, Film
11.5kΩ,1%,1/10W
SM_0603
Panasonic/Generic
22
R17, R21
2
Resistor, Film
1kΩ, 1%, 1/10W
SM_0603
Panasonic/Generic
23
R19
1
Resistor, Film
24.3kΩ, 1%, 1/10W
SM_0603
Panasonic/Generic
Terminal post, through hole, PTH
1/4 inch
OTHERS
23
P1 - P6
6
1514-2
Turrett Post
24
TP1, TP2,
TP3
3
5002
TEST POINT vertical, white PC test jack
25
JP1, JP2
2
68000-236-1X2 Header
5
PTH
Keystone
Keystone
1X2 Break Strip GOLD
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January 15, 2010
Application Note 1521
ISL6445EVAL3Z Printed Circuit Board Layers
FIGURE 15. ISL6445EVAL3Z - TOP LAYER
(SILKSCREEN)
FIGURE 17. ISL6445EVAL3Z - LAYER 2
FIGURE 19. ISL6445EVAL3Z - BOTTOM LAYER
(SOLDER SIDE)
FIGURE 16. ISL6445EVAL3Z - TOP LAYER
(COMPONENT SIDE)
FIGURE 18. ISL6445EVAL3Z - LAYER 3
FIGURE 20. ISL6445EVAL3Z - BOTTOM LAYER
(SILKSCREEN)
Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the
reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding.
For information regarding Intersil Corporation and its products, see www.intersil.com
6
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