an1332

ISL8510EVAL1Z
1A Buck Regulator with Integrated MOSFETs
®
Application Note
The ISL8510 is a high-performance, triple output controller
that provides a single, high frequency power solution for a
variety of point of load applications. The ISL8510 integrates
a 1A standard buck PWM controller and switching MOSFET
with one 500mA LDO.
The PWM controller in the ISL8510 drives an internal
switching N-Channel power MOSFET and requires an
external Schottky diode to generate an output voltage from
0.6V to 20V. The integrated power switch is optimized for
excellent thermal performance up to 1A of output current.
The standard buck input voltage range supports a fixed 5V
or variable 6V to 25V range. The PWM regulator switches at
a fixed frequency of 500kHz and utilizes simple voltage
mode control with input voltage feed forward to provide
flexibility in component selection and minimize solution size.
Protection features include overcurrent, undervoltage, and
thermal overload protection integrated into the IC. The
ISL8510 power good signal output indicates loss of
regulation on the PWM output.
The ISL8510 features adjustable LDO regulator using
internal PMOS transistors as pass devices. Enable pin
(EN_LDO) control LDO output. A single power good signal
output indicates loss of regulation on the LDO output.
Independent overcurrent and thermal fault shutdown monitor
are integrated into the LDO section.
July 10 , 2007
AN1332.0
Features
• Standard Buck Controller with Integrated Switching Power
MOSFET + 1 LDO
• Integrated Boot Diode
• Input Voltage Range
- Fixed 5V ±10%
- Variable 6V to 25V
• PWM Output Voltage Adjustable from 0.6V to 20V with
Continuous Output Current up to 1A
• Voltage Mode Control with Voltage Feed Forward
• Fixed 500kHz Switching Frequency
• Externally Adjustable Soft-Start Time
• Output Undervoltage Protection
• LDO Adjustable Options
- LDO1, 0.6V to 4.2V . . . . . . . . . . . . . . . . . . . . . . 500mA
• Individual Enable Inputs
• Two PGOOD Outputs (PWM and LDO)
• Overcurrent Protection
• Thermal Overload Protection
• Internal 5V LDO regulator
• Pb-Free Plus Anneal Available (RoHS Compliant)
ISL8510 is available in a small 4mmx4mm thin Quad Flat
No-Lead (QFN) package.
Applications
Ordering Information
• WLAN Cards-PCMCIA, Cardbus32, MiniPCI CardsCompact Flash Cards
Pinout
24 23
EN
20 19
18 VIN
VOUT1 2
17 VIN
VIN_LDO1 3
16 PHASE
25
GND
VIN_LDO2 4
15 PHASE
14 BOOT
FB_LDO2 6
13 PVCC
CC2
8
9
10 11
EN_LDO2
VOUT2 5
7
1
22 21
FB_LDO1 1
12
VCC
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which are RoHS compliant and
compatible with both SnPb and Pb-free soldering operations. Intersil
Pb-free products are MSL classified at Pb-free peak reflow
temperatures that meet or exceed the Pb-free requirements of
IPC/JEDEC J STD-020.
CC1
*Add “-T” suffix for tape and reel
SS
ISL8510
(24 LD QFN)
TOP VIEW
GND
-40 to +85 24 Ld QFN 4x4 L24.4x4D
(2.7 Sq. mm Pad)
• Hand-Held Instruments
COMP
PKG.
DWG. #
FB_PWM
PACKAGE
PG_PWM
ISL8510IRZ* 85 10IRZ
TEMP.
RANGE
(°C)
PG_LDO
PART
MARKING
EN_LDO1
PART
NUMBER
• General Purpose
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. 2007. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
Application Note 1332
What’s Inside
Evaluating the Other Output Voltage
The Evaluation Board Kit contains the following materials:
The ISL8510EVAL1Z kit outputs are preset to 3.3V, 1.2V,
1.8V; however, all of them can be programmed using resistor
dividers using Equation 1:
• The ISL8510 EVAL REV D board
R 1 ⋅ 0.6V
R 2 = ---------------------------------V OUT – 0.6V
• The ISL8510 datasheet
• This EVAL KIT document
Recommended Equipment
The following materials are recommended to perform
testing:
• 0V to 25V power supply with at least 5A source current
capability, battery, notebook AC adapter
(EQ. 1)
The output voltage programming resistor R2 will depend on
the feedback resistor R1, as referred to in Figure 1. The
value of R1 is typically between 1kΩ and 10kΩ. If the output
voltage desired is 0.6V, then R2 is left opened.
VOUT
• Two electronic loads capable of sinking current up to 5A
R1
• Digital Multimeters (DMMs)
+
EA
• 100MHz quad-trace oscilloscope
• Signal generator
R2
0.6V
REFERENCE
Quick Setup Guide
1. Ensure that the circuit is correctly connected to the supply
and loads prior to applying any power.
FIGURE 1. EXTERNAL RESISTOR DIVIDER
2. Connect the bias supply to VIN, the plus terminal to TP1
(VCC) and the negative return to TP6 (GND).
3. Verify that SW1 is on ENABLE.
TABLE 1. SWITCH 1 SETTINGS
SW1
ENABLE
OPERATING MODE
4. Turn on the power supply.
1
SW1
Enable or disable the buck controller
5. Verify the PG_PWM LED is on and that the output voltage
is 3.3V for VOUT1 (TP3).
2
SW2
Enable or disable LDO1
6. Turn on SW2 to ENABLE. If VLDO1 is connected to a
separate power supply, remove R25 from the bottom first,
then turn on SW2.
7. Verify the PG_LDO LED is on and LDO output voltage is
1.2V for VOUT2 (TP7).
2
AN1332.0
July 10 , 2007
iSL8510EVAL1Z Schematic
VCC
R29
R4
2.21K
0
20K
10K
1
0.01UF
C2
2
R3
1
3
2N7002
R15
1
10K
1
1UF
C7
2
EN_LDO1
EN_LDO2
R27
OPEN
EN_LDO2
Q3
ROHS COMPLIANT
C14
1
C21
SP1
3
4
5
1
C12
2
100UF
C13 1
2
10UF
2
TP12
VCC
10UF
2
TP11
C8
1
VIN
OPEN
1
1
1
2
12
GND 11
10
9
8
7
C6 CC2
R9
R30
TP3
2
COMBINE INDUCTOR FOOTPRINTS
10
2
2
C19
1SW3
1000PF
3
0.1UF
R5
1
TP15
R16
2
Q2
100K
1
PG_LDO
1
EN_LDO1
2N7002
C18
10K
C9
BOOT
13
VOUT1
1
10UH
POPULATE R30 IF VIN <6V ONLY
1000PF
1SW2
14
VCC
R13
2
0.1UF
C16
2
GND
3
3
22UF
3
1
Q1
2
1000PF
10K
C17
1
EP
1
25
1
R12
1
2N7002
R11
CC2
PG_LDO
EN_LDO1
EN_LDO2
GND
VCC
PVCC
TP13
BOOT
0
100K
R10
0
4
100UH
L2
15
PHASE
R26
1
OPEN
R25
D1
VCC
PHASE
1
16
D2
L1
17
VIN
PHASE
2
OPEN
2
1
VOUT1
3
2
C11
2
18
1
VLDO
3
100UH
R28
OPEN
1UF
FB_LDO1
VCC
10UF
1
1
SS
C4
19
FB
COMP
21
24
L1
1
TP7
1
TP6
TP2
1
VOUT2
TP17
VLDO
1
GND
GND
1
CC1
5.11K
2
2
PG_LDO
1
VLDO
TP5
TP1
TP4
Application Note 1332
0
R6
1
+1.2V
C15
1
22UF
R18
22
2
TP8
3
2N7002
23 0.1UF
1
CC1 C5
R7
GND
0
5.11K
PG_PWM
R17
C10
3
D4
1
1
TP16
1
Q4
1SW1
1
D3
1
2
R24
3
2N7002
3
C3
1000PF
VIN
PG_PWM
1
Q5
2
301
2
R21
10K
R20
2.43K
C1
2
10PF
10K
R23
2.43K
R2
R1
AN1332.0
July 10 , 2007
Application Note 1332
TABLE 2. COMPONENT LIST
REF DES
QTY
VALUE
TOL
C5, C6, C9
3
0.10µF
10%
50V
SM 0603
C1608X7R1H104K-T
TDK
CAPACITOR, SMD, 0603,
0.10µF, 50V, 10%, X7R
C11
1
10µF
20%
25V
SM 1210
C3225X7R1E106M-T
TDK
CAP, SMD,1210,10µF,
25V, 20%, X7R, ROHS
C2
1
10pF
5%
50V
SM 0402
H1044-00100-50V5-T
VENKEL
CAP, SMD, 0402, 10pF, 50V,
5%, NPO, ROHS
C3,
C17-C19
4
1000pF
10%
50V
SM 0402
H1044-00102-50V10-T
VENKEL,
PANASONIC,
MURATA
CAP, SMD, 0402, 1000pF,
50V, 10%, X7R, ROHS
C1
1
0.01µF
10%
16V
SM 0402
H1044-00103-16V10-T
NIC COMP CORP, CAP, SMD, 0402, 0.01µF,
PHILLIPS, VENKEL, 16V, 10%, X7R, ROHS
KEMET
C4
1
33000pF
20%
16V
SM 0402
H1044-00333-16V8020-T
PANASONIC
CAP, SMD, 0402, 33000pf,
16V, +80-20%, Y5V, ROHS
C14
1
10µF
10%
6.3V
SM 0805
H1046-00106-6R3V10-T
VENKEL, AVX,
MURATA
CAP, SMD, 0805, 10µF, 6.3V,
10%, X5R, ROHS
C7
1
1µF
10%
50V
SM 1206
H1065-00105-50V10-T
VENKEL
CAP, SMD, 1206, 1µF, 50V,
10%, X7R, ROHS
C8
1
DNP
10%
50V
SM 1206
H1065-00105-50V10-T
VENKEL
CAP, SMD, 1206, 1µF, 50V,
10%, X7R, ROHS
C13
1
10µF
10%
25V
SM 1206
H1065-00106-25V10-T
VENKEL
CAP, SMD, 1206, 10µF, 25V,
10%, X5R, ROHS
C15
1
22µF
10%
6.3V
SM 1206
H1065-00226-6R3V10-T
MURATA, KEMET,
AVX
CAP, SMD, 1206, 22µF, 6.3V,
10%, X5R, ROHS
C16
1
DNP
10%
6.3V
SM 1206
H1065-00226-6R3V10-T
MURATA, KEMET,
AVX
CAP, SMD, 1206, DNP, DNP,
DNP, X5R, ROHS
C10
1
4.7pF
5.40%
50V
SM 1206
H1065-004R7-50VR25-T
VENKEL
CAP, SMD, 1206, 4.7pF, 50V,
0.25pF, NPO, ROHS
C12
1
100µF
20%
6.3V
SM 1210
H1082-00107-6R3V20-T
GENERIC
CAP, SMD, 1210, 100µF,
6.3V, 20%, X5R, ROHS
L2
1
10µH
20%
102mΩ
6.9x6.5
DNP (SP1)
0
DNP
-
-
-
131-5031-00
TEKTRONIX
CONN-SCOPE PROBE
TEST PT, COMPACT, PCB
MNT
TP1-TP8
8
-
-
-
-
1514-2
KEYSTONE
CONN-TURRET, TERMINAL
POST, TH, ROHS
TP9-TP10
2
DNP
-
-
-
1514-2
KEYSTONE
CONN-TURRET, TERMINAL
POST, TH, ROHS
TP11-TP14,
TP16-TP17
6
-
-
-
-
5002
KEYSTONE
CONN-MINI TEST POINT,
VERTICAL, WHITE, ROHS
TP15
1
DNP
-
-
-
5002
KEYSTONE
CONN-MINI TEST POINT,
VERTICAL, WHITE, ROHS
D1
1
-
-
-
-
B340LB-13-F-T
DIODES INC
DIODE-SCHOTTKY, SMD,
SMB, 2P, 40V, 3A LOW VF,
Pb-free
D3, D4
2
-
-
-
-
LTST-C170CKT
LITEON, VISHAY,
ROHM, STANLEY
ELECTRIC
LED-GaAs RED, SMD,
2mmx1.25mm, 100mW,
40mA, 10mcd, ROHS
4
VOLTAGE PACKAGE
PART NUMBER
MANUFACTURER
IHLP-2525CZ-ER-10R-M01 VISHAY
DESCRIPTION
COIL-PWR INDUCTOR, SMD,
6.9mmx6.5mm, 10µH, 20%,
3A, ROHS
AN1332.0
July 10 , 2007
Application Note 1332
TABLE 2. COMPONENT LIST (Continued)
REF DES
QTY
VALUE
TOL
U1
1
-
-
-
QFN
ISL8510IRZ
Q1-Q5
5
-
-
60V
SOT-23
2N7002-7-F-T
R17, R18
2
0Ω
5%
50V
SM 0402
H2510-00R00-1/16W-T
VENKEL,
PANASONIC
RES, SMD, 0402, 0Ω, 1/16W,
5%, TF, ROHS
R2, R11,
R13, R15
4
10k
1%
50V
SM 0402
H2510-01002-1/16W1-T
PANASONIC,
VENKEL
RES, SMD, 0402, 10k, 1/16W,
1%, TF, ROHS
R12, R14,
R16
3
100k
1%
50V
SM 0402
H2510-01003-1/16W1-T
PANASONIC
RES, SMD, 0402, 100k,
1/16W, 1%, TF, ROHS
R1
1
20k
1%
50V
SM 0402
H2510-02002-1/16W1-T
PANASONIC
RES, SMD, 0402, 20k, 1/16W,
1%, TF, ROHS
R4
1
2.21k
1%
50V
SM 0402
H2510-02211-1/16W1-T
PANASONIC,
VENKEL
RES, SMD, 0402, 2.21k,
1/16W, 1%, TF, ROHS
R8-R9
2
DNP
1%
50V
SM 0402
H2510-02551-1/16W1-T
VENKEL, VISHAY,
DALE
RES, SMD, 0402, DNP, DNP,
DNP, TF, ROHS
R3
1
301Ω
1%
50V
SM 0402
H2510-03010-1/16W1-T
PANASONIC,
VENKEL
RES, SMD, 0402, 301Ω,
1/16W, 1%, TF, ROHS
R6-R7
2
5.11k
1%
50V
SM 0402
H2510-05111-1/16W1-T
PANASONIC
RES, SMD, 0402, 5.11k,
1/16W, 1%, TF, ROHS
R5, R10,
R29
3
0Ω
1%
75V
SM 0603
H2511-00R00-1/10W-T
GENERIC
RESISTOR, SMD, 0603,
0Ω, 1/10W, TF, ROHS
R21, R24
2
10k
1%
75V
SM 0603
H2511-01002-1/10W1-T
KOA, VENKEL
RES, SMD, 0603, 10k, 1/10W,
1%, TF, ROHS
R20, R23
2
2.43k
1%
75V
SM 0603
H2511-02431-1/10W1-T
VENKEL, YAGEO
RES, SMD, 0603, 2.43k,
1/10W, 1%, TF, ROHS
R25
1
0Ω
1%
200V
SM 1206
H2513-00R00-1/4W-T
VISHAY, VENKEL
RES, SMD, 1206, 0Ω, 1/4W,
TF, ROHS
R26-R28,
R30
0
DNP
1%
200V
SM 1206
H2513-DNP
GENERIC
RES, SMD, 1206, DNP, DNP,
DNP, TF, ROHS
SW1-SW2
2
-
-
-
-
GT11MSCBE-T
C&K
COMPONENTS
SWITCH-TOGGLE, SMD,
ULTRAMINI, 1P, SPST MINI
SW3
1
DNP
-
-
-
GT11MSCBE-T
C&K
COMPONENTS
SWITCH-TOGGLE, SMD,
ULTRAMINI, 1P, SPST MINI
C20, C21
0
DNP
-
-
-
DNP
DO NOT POPULATE OR
PURCHASE
D2
0
DNP
-
-
-
DNP
DO NOT POPULATE OR
PURCHASE
L1
0
DNP
-
-
-
DNP
DO NOT POPULATE OR
PURCHASE
5
VOLTAGE PACKAGE
PART NUMBER
MANUFACTURER
INTERSIL
DESCRIPTION
IC-2A BUCK REGULATOR,
24P, QFN, 4x4, ROHS
DIODES, INC, ON
TRANSISTOR, N-CHANNEL,
SEMICONDUCTOR 3 LD, SOT-23, 60V, 115mA,
ROHS
AN1332.0
July 10 , 2007
Application Note 1332
ISL8510EVAL1Z Board Layout
FIGURE 2. TOP COMPONENTS
FIGURE 3. TOP LAYER ETCH
6
AN1332.0
July 10 , 2007
Application Note 1332
ISL8510EVAL1Z Board Layout
(Continued)
FIGURE 4. 2ND LAYER ETCH
FIGURE 5. 3RD LAYER ETCH
7
AN1332.0
July 10 , 2007
Application Note 1332
ISL8510EVAL1Z Board Layout
(Continued)
FIGURE 6. BOTTOM LAYER COMPONENTS (MIRRORED)
FIGURE 7. BOTTOM LAYER ETCH (MIRRORED)
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
8
AN1332.0
July 10 , 2007
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