an1443

ISL85001EVAL1Z: 1A
Regulator Standard Buck PWM
®
Application Note
December 1, 2008
AN1443.0
Description
Recommended Equipment
The ISL85001EVAL1Z REV A kit is intended for use by
individuals with requirements for Point-of-Load applications
sourcing from 4.5V to 25V. The ISL85001EVAL1Z evaluation
board is used to demonstrate the performance of the
ISL85001 standard buck regulator.
The Following Materials are Recommended to Perform
Testing:
The ISL85001 is offered in a 4mmx3mm 12 Ld DFN package
with 1mm maximum height. The complete converter
occupies less than 0.425in2 area.
• 0V to 25V Power Supply with at Least 5A Source Current
Capability, Battery, Notebook AC Adapter
• One Electronic Load Capable of Sinking Current up to 5A
• Digital Multimeters (DMMs)
• 100MHz Quad-Trace Oscilloscope
Features
• Signal Generator
• Standard Buck Controller with Integrated Switching Power
MOSFET
Quick Setup Guide
• Integrated Boot Diode
1. Ensure that the circuit is correctly connected to the supply
and loads prior to applying any power.
• Input Voltage Range
- Fixed 5V ±10%
- Variable 5.5V to 25V
2. Connect the bias supply to VIN, the plus terminal to TP1
(VIN) and the negative return to TP2 (GND).
• PWM Output Voltage Adjustable from 0.6V to 19V with
Continuous Output Current up to 1A
4. Turn on the power supply.
3. Verify that SW1 is on ENABLE.
• Voltage Mode Control with Voltage Feed-Forward
5. Verify the PG is on and the output voltage is 2.5V for
VOUT(TP3).
• Fixed 500kHz Switching Frequency
Evaluating the Other Output Voltage
• Externally Adjustable Soft-Start Time
The ISL85001EVAL kit outputs are preset to 2.5V; however,
it can be programmed using resistor dividers using
Equation 1:
• Output Undervoltage Protection
• Enable Inputs
R 1 ⋅ 0.6V
R 2 = ---------------------------------V OUT – 0.6V
• PGOOD Output
• Overcurrent Protection
(EQ. 1)
The output voltage programming resistor R2 will depend on
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.
• Thermal Overload Protection
• Internal 5V LDO regulator
Applications
VOUT
• General Purpose
R1
• WLAN Cards-PCMCIA, Cardbus32, MiniPCI
Cards-Compact Flash Cards
+
EA
R2
• Hand-Held Instruments
• LCD Panel
0.6V
REFERENCE
• Set-top Box
FIGURE 1. EXTERNAL RESISTOR DIVIDER
What’s Inside
The Evaluation Board Kit contains the following materials:
• The ISL85001 EVAL REV A board
• The ISL85001 datasheet
TABLE 1. SWITCH 1 SETTINGS
SW1
1
ENABLE
SW1
OPERATING MODE
Enable or disable the buck controller
• This EVAL KIT document
1
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. 2008. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
Application Note 1443
ISL85001EVAL1Z Schematic
C1
2
30K
1
R2
2200PF
C2
10K
VIN
1
1
1
C20
2
TP3
C8
EP
1
4 SP1
2
3
0.1UF
VDD
4 SP2
1
1
2
1
1
C9
BOOT
2
8
C21
GND
VOUT
1
OPEN
BOOT
PG
L1
PHASE
2
67
13
PHASE
EN
10
9
C12
5
11
47UF
C13
4
VIN
PHASE
SS
2
EN
PG
COMP
3
0.1UF
VIN
FB
1
3
1
TP2
12
D1
C4
1
2
2
2
2
TP1
GND
1
1
2
COMP
3
1
U1
OPEN
1
C10
3.16K
TP16
FB
1
PG
10UF
C11
D3
1
C3
470PF
R4
2N7002
Q4
2
301
220UF
R3
47PF
1UF
10K
R21
R1
2
R20
2.43K
VDD
1
TP4
2
ISL8500IRZ
TP13
R30
VIN
OPEN
POPULATE R30 IF VIN <6V ONLY
1
R12
100K
VDD
ON
EN
3
SW1
1
2
OFF
2
AN1443.0
December 1, 2008
Application Note 1443
ISL85001EVAL1Z Bill of Materials
PART NUMBER
REFERENCE
DESIGNATOR
QTY UNITS
DESCRIPTION
MFR
MANUFACTURER
PART
ISL85001EVAL1ZREVAPCB
1
ea
See Label-Rename
Board
PWB-PCB,
ISL85001EVAL1Z, REVA,
ROHS
TITAN
ISL85001EVAL1ZREVAPCB
C1608X7R1H104K-T
1
ea
C9
CAPACITOR, SMD, 0603,
0.10µF, 50V, 10%, X7R
TDK
C1608X7R1H104K
H1044-00104-16V10-T
1
ea
C4
CAP, SMD, 0402, 0.1µF, 16V,
10%, X7R, ROHS
MURATA
GRM36X7R104K016AD
H1044-00222-50V10-T
1
ea
C1
CAP, SMD, 0402, 2200pF,
50V, 10%, X7R, ROHS
PANASONIC
ECJ-0EB1H222K
H1044-00470-50V5-T
1
ea
C2
CAP, SMD, 0402, 47pF, 50V,
5%, NPO, ROHS
MURATA
GRM36COG470J050AQ
H1044-00471-50V10-T
1
ea
C3
CAP, SMD, 0402, 470pF, 50V, PANASONIC
10%, X7R, ROHS
ECJ-0EB1H471K
H1045-00105-6R3V10-T
1
ea
C8
CAP, SMD, 0603, 1µF, 6.3V,
10%, X5R, ROHS
PANASONIC
ECJ1VB0J105K
H1065-00106-25V10-T
1
ea
C10
CAP, SMD,1206,10µF, 25V,
10%, X5R, ROHS
VENKEL
C1206X5R250-106KNE
H1082-00476-16V20-T
1
ea
C12
CAP, SMD, 1210, 47µF, 16V,
20%, x5R, ROHS
TDK
C3225X5R1C476M
IHLP2525CZER220M11
1
ea
L1
COIL-PWR INDUCTOR,
SMD, 6.9x6.5, 22µH, 20%,
7A, ROHS
VISHAY
IHLP2525CZER220M11
131-4353-00
2
ea
SP1, SP2
CONN-SCOPE PROBE TEST TEKTRONIX
PT, COMPACT, PCB MNT,
ROHS
131-4353-00
1514-2
4
ea
TP1 to TP4
CONN-TURRET, TERMINAL
POST, TH, ROHS
KEYSTONE
1514-2
5002
2
ea
TP13, TP16
CONN-MINI TEST POINT,
VERTICAL, WHITE, ROHS
KEYSTONE
5002
B340LB-13-F-T
1
ea
D1
DIODE-SCHOTTKY, SMD,
SMB, 2P, 40V, 3A LOW VF,
ROHS
DIODES INC.
B340LB-13-F
LTST-C170CKT
1
ea
D3
LED-GaAs RED, SMD,
2x1.25mm,100mW, 40mA,
10mcd, ROHS
LITEON/VISHA
Y
LTST-C170CKT
ISL85001IRZ
1
ea
U1
IC-2A BUCK REGULATOR,
12P, DFN, 4x3, ROHS
INTERSIL
ISL85001IRZ
2N7002-7-F-T
1
ea
Q4
TRANSISTOR, N-CHANNEL,
3LD, SOT-23, 60V, 115mA,
ROHS
DIODES,INC.
2N7002-7-F
H2510-01002-1/16W1-T
1
ea
R2
RES, SMD, 0402, 10k, 1/16W, PANASONIC
1%, TF, ROHS
ERJ-2RKF1002
H2510-01003-1/16W1-T
1
ea
R12
RES, SMD, 0402, 100k,
1/16W, 1%, TF, ROHS
ERJ2RKF1003
H2510-03002-1/16W1-T
1
ea
R1
RES, SMD, 0402, 30k, 1/16W, YAGEO
1%, TF, ROHS
RC0402FR-0730KL
H2510-03010-1/16W1-T
1
ea
R3
RES, SMD, 0402, 301Ω,
1/16W, 1%, TF, ROHS
ERJ-2RKF3010X
3
PANASONIC
PANASONIC
AN1443.0
December 1, 2008
Application Note 1443
ISL85001EVAL1Z Bill of Materials (Continued)
PART NUMBER
QTY UNITS
REFERENCE
DESIGNATOR
DESCRIPTION
MFR
H2510-03161-1/16W1-T
1
ea
R4
RES, SMD, 0402, 3.16k,
1/16W, 1%, TF, ROHS
H2511-01002-1/10W1-T
1
ea
R21
RES, SMD, 0603, 10k, 1/10W, KOA
1%, TF, ROHS
RK73H1JT1002F
H2511-02431-1/10W1-T
1
ea
R20
RES, SMD, 0603, 2.43k,
1/10W, 1%, TF, ROHS
VENKEL
CR0603-10W-2431FT
H2511-DNP
0
ea
R30
RES, SMD, 0603, DNPPLACE HOLDER, ROHS
GT11MSCBE-T
1
ea
SW1
SWITCH-TOGGLE, SMD,
ULTRAMINI, 1P, SPST MINI
C&K
COMPONENTS
GT11MSCKE
4-40x1/2-SCREW
4
ea
Four corners
SCREW, 4-40x1/2in, PAN,
NYLON, PHILLIPS, ROHS
4-40x3/4-STANDOFF
4
ea
Four corners
STANDOFF, 4-40x3/4in, F/F,
HEX, NYLON
KEYSTONE
1902D
5x8-STATIC-BAG
1
ea
Place assy in bag.
BAG, STATIC, 5x8, ZIP LOC
INTERSIL
212403-013
DNP
0
ea
C11, C13, C20, C21 DO NOT POPULATE OR
PURCHASE
LABEL-RENAME BOARD
1
ea
RENAME PCB TO:
ISL85001EVAL1Z
LABEL-SERIAL NUMBER
1
ea
4
VENKEL
MANUFACTURER
PART
CR0402-16W-3161FT
LABEL, TO RENAME BRD
LABEL, FOR SERIAL
NUMBER AND BOM REV #
AN1443.0
December 1, 2008
Application Note 1443
ISL85001EVAL1Z Board Layout
ISL85001EVAL1Z
FIGURE 2. TOP COMPONENTS
FIGURE 3. TOP LAYER ETCH
5
AN1443.0
December 1, 2008
Application Note 1443
ISL85001EVAL1Z Board Layout
(Continued)
FIGURE 4. BOTTOM LAYER COMPONENTS (MIRRORED)
FIGURE 5. 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
6
AN1443.0
December 1, 2008
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