an1365

Application Note 1365
ISL8013AEVAL2Z: 3A Low Quiescent Current 1MHz
High Efficiency Synchronous Buck Regulator
Description
Quick Setup Guide
The ISL8013AEVAL2Z kit is intended for use by
individuals with requirements for Point-of-Load
applications sourcing from 2.7V to 5.5V. The
ISL8013AEVAL2Z evaluation board is used to
demonstrate the performance of the ISL8013A low
quiescent current mode converter.
The ISL8013A is offered in a 4mmx4mm 16 Ld QFN
package with 1mm maximum height. The complete
converter occupies less than 0.4in2 area. The ISL8014A
is pin-to-pin compatible with the ISL8013A.
Key Features
• High Efficiency Synchronous Buck Regulator with up
to 95% Efficiency
• Power-Good (PG) Output with 1ms Delay
1. Ensure that the circuit is correctly connected to the
supply and loads prior to applying any power.
2. Connect the bias supply to VIN. Plus terminal to P4
(VIN) and negative return to P5 (GND).
3. Verify that position is ON for SW1.
4. Turn on the power supply.
5. Verify the output voltage is 1.8V for VOUT
Evaluating the Other Output Voltage
The ISL8013AEVAL2Z kit output is preset to 1.8V;
however, output voltages can be adjusted from 0.8V to
3.3V using Equations 1 and 2:
R 1⎞
⎛
V OUT = 0.8 ⎜ 1 + -------⎟
R 2⎠
⎝
• 2.7V to 5.5V Supply Voltage
Let’s set R1 = 124kΩ
• 3% Output Accuracy Over-Temperature/Load/Line
( R1 )
R 2 = ------------------------------V OUT
⎛ ----------------⎞ – 1
⎝ 0.8 ⎠
• 3A Guaranteed Output Current
• Start-up with Pre-biased Output
• Internal Digital Soft-Start - 1ms
• Soft-Stop Output Discharge During Disabled
(EQ. 1)
(EQ. 2)
Note: If desired output is 0.8V, then short R1 and open
R2.
• 35µA Quiescent Supply Current in PFM Mode
Mode Control
• Selectable Forced PWM Mode and PFM Mode
The ISL8013A has a SKIP pin that controls the operation
mode. When the SKIP pin is driven to low or shorted to
ground, the regulator operates in a PFM mode. Set SKIP
pin high forced PWM mode. The controller remains in the
fixed PWM frequency at light load instead of entering the
skip mode. In an application where a situation requires
the ISL8013A regulator to sink more than 2A valley
inductor current, it is recommended to operate in PFM to
avoid any possible over stress.
• External Synchronization up to 4MHz
• Less than 1µA Logic Controlled Shutdown Current
• 100% Maximum Duty Cycle for Lowest Dropout
• Internal Current Mode Compensation
• Peak Current Limiting and Hiccup Mode Short Circuit
Protection
• Over-Temperature Protection
TABLE 1. SWITCH 1 SETTINGS
Recommended Equipment
The following materials are recommended to perform
testing:
• 0V to 10V Power Supply with at least 5A source
current capability or 5V battery
• Electronic Loads capable of sinking current up to 5A
• Digital Multimeters (DMMs)
• 100MHz quad-trace oscilloscope
SW1
ENABLE
ON/OFF CONTROL
1
OFF
Disable VOUT
3
ON
Enable VOUT
SW2
SKIP
FUNCTION
1
PWM
Fixed PWM frequency at light load
3
PFM
Force continuous mode
• Signal generator
December 16, 2009
AN1365.3
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. 2007, 2008, 2009. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
Application Note 1365
ISL8013AEVAL2Z Schematic
J1
16 15
14
NC LX
P4
P5
VIN
1
1
VIN
2
1
1
C1
22µF
C2
22µF
2
2
1
2
R10
1
2
4 3 2
A
L1
1.5µH
LX
LX
12
2
11
PG
FB
5
6
7
8
R2
100k
VIN
1
R5
2k
1
2
SYNCH
P2
D1
PG
1
2
R7
100k
2N7002
Q1
3
SW2
1
21
31
VIN
A
R6
100k
2
1
P8
2
2
P3
1
2
2
A
VIN
1
C6
22µF
A
NC
A
R4
100k
C5
22µF
9
SGND
EN
P7
1
2
1
A
2
1
C4
47pF
R1
124k
U1
10
VDD ISL8013AIRZ SGND
A
1
VOUT
1
PGND
4
SYNCH
SYNCH
EP
17
1
J2
13
PGND
VIN
3
1
C3
OPEN
LX
1
2
4 3
1
PWM
1
P6
ON
OFF
1
2
2
R9
OPEN
A
3
SW1
1
PFM
R8
OPEN
1
1
2
2
EN
A
A
NOTE: Pin 16 is a no connect pin which can tie to VIN, SGND, or LX
2
AN1365.3
December 16, 2009
Application Note 1365
ISL8013AEVAL2Z Bill of Materials
PART NUMBER
REFERENCE
QTY DESIGNATOR
ISL8013AEVAL2Z
1
H1045-00470-50V5-T
1
H1045-DNP
0
H1065-00226-6R3V10-T
4
DESCRIPTION
MANUFACTURER
PWB-PCB, ISL8013AEVAL2Z,
REVA, ROHS
C4
C3
CAP, SMD, 0603, 47pF, 50V,
5%, NPO, ROHS
1
L1
131-4353-00
2
J1, J2
1514-2
4
5002
LTST-C170CKT
ISL8013AEVAL2ZREVAPCB
AVX
06035A470JAT2A
PHILLIPS
0603X7R500-562KNE
MURATA
GRM31CR60J226KE19L
KEMET
C1206C226K9PACTU
AVX
12066D226KAT2A
COOPER
ELECTRONIC TECH.
DR73-1R5-R
CAP, SMD, 0603, DNP-PLACE
HOLDER, ROHS
C1, C2, C5, C6 CAP, SMD, 1206, 22µF, 6.3V,
10%, X5R, ROHS
DR73-1R5-R
MANUFACTURER PART
COIL-PWR INDUCTOR, SMD,
7.5mm, 1.5µH, 20%, 6.52A,
ROHS
CONN-SCOPE PROBE TEST PT, TEKTRONIX
COMPACT, PCB MNT, ROHS
131-4353-00
P4, P5, P7, P8
CONN-TURRET, TERMINAL
POST, TH, ROHS
KEYSTONE
1514-2
3
P2, P3, P6
CONN-MINI TEST POINT,
VERTICAL, WHITE, ROHS
KEYSTONE
5002
1
D1
LED-GaAs RED, SMD,
2mmx1.25mm, 100mW,
40mA, 10mcd, ROHS
LITEON/VISHAY
LTST-C170CKT
ROHM
SML-210LTT86
STANLEY ELECTRIC
BR112H-TR
ISL8013AIRZ
1
U1
IC-3A, 1MHz, BUCK
REGULATOR, 16P, QFN, 4x4,
ROHS
INTERSIL
ISL8013AIRZ
2N7002-7-F-T
1
Q1
TRANSISTOR, N-CHANNEL,
3LD, SOT-23, 60V, 115mA,
ROHS
DIODES, INC.
2N7002-7-F
H2511-00R00-1/10W-T
1
H2511-01003-1/10W1-T
4
H2511-01243-1/10W1-T
1
H2511-02001-1/10W1-T
R10
ON SEMICONDUCTOR 2N7002LT1G
RESISTOR, SMD, 0603, 0Ω,
1/10W, TF, ROHS
R2, R4, R6, R7 RES, SMD, 0603, 100k, 1/10W,
1%, TF, ROHS
R1
1
R5
H2511-DNP
0
R8, R9
GT11MSCBE-T
2
SW1, SW2
LABEL-SERIAL NUMBER
1
RES, SMD, 0603, 124k, 1/10W, YAGEO
1%, TF, ROHS
PANASONIC
RES, SMD, 0603, 2k, 1/10W,
1%, TF, ROHS
9C06031A1243FKHFT
ERJ-3EK1243V
KOA
RK73H1JTTD2001F
VENKEL
CR0603-10W-2001FT
C&K COMPONENTS
GT11MSCKE
RES, SMD, 0603, DNP-PLACE
HOLDER, ROHS
SWITCH-TOGGLE, SMD,
ULTRAMINI, 1P, SPST MINI
LABEL, FOR SERIAL NUMBER
AND BOM REV #
3
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December 16, 2009
Application Note 1365
ISL8013AEVAL2Z Board Layout
ISL8013AEVAL2Z
FIGURE 1. TOP COMPONENTS
FIGURE 2. TOP LAYER ETCH
4
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December 16, 2009
Application Note 1365
ISL8013AEVAL2Z Board Layout
(Continued)
FIGURE 3. 2ND LAYER ETCH
FIGURE 4. 3RD LAYER ETCH
5
AN1365.3
December 16, 2009
Application Note 1365
ISL8013AEVAL2Z Board Layout
(Continued)
FIGURE 5. BOTTOM LAYER COMPONENTS (MIRRORS)
FIGURE 6. BOTTOM LAYER ETCH (MIRROR)
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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