USER’S MANUAL
ISL8501EVAL1Z
Evaluation Board
The ISL8501 is a high-performance, triple output controller
that provides a single, high frequency power solution for a
variety of point of load applications. The ISL8501 integrates
a 1A standard buck PWM controller and switching MOSFET
with two 500mA LDOs.
The PWM controller in the ISL8501 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
ISL8501 power good signal output indicates loss of
regulation on the PWM output.
The ISL8501 features two adjustable LDO regulators using
internal PMOS transistors as pass devices. Separate enable
pins (EN_LDO1, EN_LDO2) control each LDO output. A
single power good signal output indicates loss of regulation
on either of the two LDO outputs. Independent overcurrent
and thermal fault shutdown monitors are integrated into the
LDO section.
ISL8501 is available in a small 4mmx4mm thin Quad Flat
No-Lead (QFN) package.
AN1326
Rev 0.00
July 10, 2007
Features
• Standard Buck Controller with Integrated Switching Power
MOSFET + Dual LDOs
• 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
• Dual LDO Adjustable Options
- LDO1, 0.6V to 4.2V . . . . . . . . . . . . . . . . . . . . . . 500mA
- LDO2, 0.6V to 4.2V . . . . . . . . . . . . . . . . . . . . . . 500mA
• Individual Enable Inputs
• Two PGOOD Outputs (PWM and both LDOs)
• Overcurrent Protection
• Thermal Overload Protection
• Internal 5V LDO regulator
Applications
• General Purpose
• WLAN Cards-PCMCIA, Cardbus32, MiniPCI Cards-
Compact Flash Cards
• Hand-Held Instruments
Ordering Information
PART
NUMBER
PART
MARKING
TEMP.
RANGE
(°C)
PACKAGE
PKG.
DWG. #
Pinout
PG_PWM
FB_PWM
COMP
CC1
EN
19
18 VIN
17 VIN
25
GND
16 PHASE
15 PHASE
14 BOOT
13 PVCC
7
CC2
8
PG_LDO
9
EN_LDO1
10
EN_LDO2
11
GND
12
VCC
SS
20
ISL8501IRZ* 85 01IRZ
-40 to +85 24 Ld QFN 4x4 L24.4x4D
(2.7 Sq. mm Pad)
*Add “-T” suffix for tape and reel
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.
FB_LDO1
VOUT1
VIN_LDO1
VIN_LDO2
VOUT2
FB_LDO2
1
2
3
4
5
6
24
23
22
21
AN1326 Rev 0.00
July 10, 2007
Page 1 of 9
ISL8501EVAL1Z
What’s Inside
The Evaluation Board Kit contains the following materials:
• The ISL8501 EVAL REV D board
• The ISL8501 datasheet
• This EVAL KIT document
Evaluating the Other Output Voltage
The ISL8501EVAL kit outputs are preset to 3.3V, 1.2V, 1.8V;
however, all of them can be programmed using resistor
dividers using Equation 1:
R
1
0.6V
R
2
= ----------------------------------
V
OUT
–
0.6V
(EQ. 1)
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
• Three electronic loads capable of sinking current up to 5A
• Digital Multimeters (DMMs)
• 100MHz quad-trace oscilloscope
• Signal generator
The output voltage programming resistor R
2
will depend on
on the feedback resistor R
1
, as referred to in Figure 1. The
value of R
1
is typically between 1k and 10k. If the output
voltage desired is 0.6V, then R
2
is left opened.
V
OUT
R1
+
-
R2
0.6V
REFERENCE
EA
Quick Setup Guide
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, the plus terminal to TP1
(VCC) and the negative return to TP6 (GND).
3. Verify that SW1 is on ENABLE.
4. Turn on the power supply.
5. Verify the PG_PWM LED is on and that the output voltage
is 3.3V for VOUT1 (TP3).
6. Turn on SW2 and SW3 to ENABLE. If VLDO1 is
connected to a separate power supply, remove R
25
from
the bottom first, then turn on SW2 and SW3.
7. Verify the PG_LDO LED is on and LDO output voltages
are 1.2V for VOUT2 (TP7) and 1.8V for VOUT3 (TP8).
SW1
1
2
3
SW1
SW2
SW3
FIGURE 1. EXTERNAL RESISTOR DIVIDER
TABLE 1. SWITCH 1 SETTINGS
ENABLE
OPERATING MODE
Enable or disable the buck controller
Enable or disable LDO1
Enable or disable LDO2
AN1326 Rev 0.00
July 10, 2007
Page 2 of 9
R24
10K
D3
2
1
2
C10
1
D4
1
4.7UF
C11
3
23
0.1UF
22
FB
21
COMP
20
C4
SS
2
1
19
0.033UF
C20
CC1
C5
24
22UF
R6
OPEN
R27
PG_LDO
1
CC1
PG_PWM
FB_PWM
COMP
SS
EN
0
5.11K
Q5
1
+1.2V
TP17
2
C15
1
2N7002
R18
EN_PWM
1
L1
100UH
R28
OPEN
L1
100UH
L2
10UH
3
2
D2
1
R26
OPEN
R25
0
2
TP7
1
FB_LDO1
1
VLDO
2
3
4
5
FB_LDO1
VOUT1
VIN_LDO1
VIN_LDO2
VOUT2
FB_LDO2
EP
VIN
18
17
16
15
14
13
TP11
VOUT2
2
4
1
VCC
R10
2
C12
1
2
C13
1
10UF
TP13
OPEN
1UF
100K
VCC
CC2
PG_LDO
EN_LDO1
EN_LDO2
GND
VCC
0
R12
R8
22UF
1
+1.8V
2
C16
1
5.11K
25
2
C8
TP9
VOUT3
1
2
FB_LDO2
1
6
PVCC
0.1UF
C21
BOOT
100UF
ISL8501
D1
BOOT
C9
1
U1
VIN
PHASE
PHASE
PHASE
VOUT1
1
1
1
2
2
3
4
5
1
10UF
C14
0
TP8
1
R7
Q4
5.11K
2N7002
1
R17
PG_PWM
GND
10UF
1
3
2
2
0.1UF
8
C6
CC2
7
GND
TP14
1000PF
R9
C17
10K
2
GND
2.55K
1
SW1
2
R11
R14
3
1
2N7002
100K
EN_PWM
3
9
10
11
12
1
PG_LDO
3
1000PF
C18
TP15
10K
2
100K
R16
1
SW2
Q2
3
1
SW3
2
R15
1000PF
10K
1
3
2N7002
Q3
1
EN_LDO2
TITLE:
REV:
2
1UF
3
C7
2
R13
1
2N7002
1
EN_LDO1
EN_LDO1
EN_LDO2
2
C19
AN1326 Rev 0.00
July 10, 2007
Page 3 of 9
Schematic
R29
0
ISL8501EVAL1Z
VCC
R4
2.21K
R1
2
2.43K
R2
C1
1
R20
10K
2.43K
R23
10K
R21
20K
C2
10PF
0.01UF
R3
301
2
C3
1000PF
2
1
1
TP16
PG_PWM
1
VIN
GND
VLDO
TP1
TP2
TP5
TP6
1
VLDO
GND
1
1
TP3
SP1
TP4
R5
10
R30
OPEN
COMBINE INDUCTOR FOOTPRINTS
VIN
Q1
TP10
1
VCC
1
POPULATE R30 IF VIN <6V ONLY
TP12
VCC
ROHS COMPLIANT
8
7
6
5
4
3
ISL8501EVAL1
REV C
ENGINEER:
ROS
DRAWN BY:
ROS
2
A
DATE:
MAY 2
SHEET:
1
O
1
ISL8501EVAL1Z
TABLE 2. COMPONENT LIST
REF DES
C5, C6, C9
C11
C2
C3,
C17-C19
C1
QTY
3
1
1
4
VALUE
0.10µF
10µF
10pF
1000pF
TOL
10%
20%
5%
10%
VOLTAGE PACKAGE
50V
25V
50V
50V
SM 0603
SM 1210
SM 0402
SM 0402
PART NUMBER
C1608X7R1H104K-T
C3225X7R1E106M-T
H1044-00100-50V5-T
H1044-00102-50V10-T
MANUFACTURER
TDK
TDK
VENKEL
VENKEL,
PANASONIC,
MURATA
DESCRIPTION
CAPACITOR, SMD, 0603,
0.10µF, 50V, 10%, X7R
CAP, SMD,1210,10µF,
25V, 20%, X7R, ROHS
CAP, SMD, 0402, 10pF, 50V,
5%, NPO, ROHS
CAP, SMD, 0402, 1000pF,
50V, 10%, X7R, ROHS
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
PANSONIC
VENKEL, AVX,
MURATA
VENKEL
VENKEL
VENKEL
MURATA, KEMET,
AVX
VENKEL
GENERIC
CAP, SMD, 0402, 33000pf,
16V, +80-20%, Y5V, ROHS
CAP, SMD, 0805, 10µF, 6.3V,
10%, X5R, ROHS
CAP, SMD, 1206, 1µF, 50V,
10%, X7R, ROHS
CAP, SMD, 1206, 1µF, 50V,
10%, X7R, ROHS
CAP, SMD, 1206, 10µF, 25V,
10%, X5R, ROHS
CAP, SMD, 1206, 22µF, 6.3V,
10%, X5R, ROHS
CAP, SMD, 1206, 4.7pF, 50V,
0.25pF, NPO, ROHS
CAP, SMD, 1210, 100µF,
6.3V, 20%, X5R, ROHS
COIL-PWR INDUCTOR, SMD,
6.9mmx6.5mm, 10µH, 20%,
3A, ROHS
CONN-SCOPE PROBE
TEST PT, COMPACT, PCB
MNT
CONN-TURRET, TERMINAL
POST, TH, ROHS
CONN-MINI TEST POINT,
VERTICAL, WHITE, ROHS
DIODE-SCHOTTKY, SMD,
SMB, 2P, 40V, 3A LOW VF,
Pb-free
LED-GaAs RED, SMD,
2mmx1.25mm, 100mW,
40mA, 10mcd, ROHS
IC-2A BUCK REGULATOR,
24P, QFN, 4x4, ROHS
C4
C14
C7
C8
C13
C15, C16
C10
C12
L2
1
1
1
1
1
2
1
1
1
33000pF
10µF
1µF
Open
10µF
22µF
4.7pF
100µF
10µH
20%
10%
10%
10%
10%
10%
5.40%
20%
20%
16V
6.3V
50V
50V
25V
6.3V
50V
6.3V
102m
SM 0402
SM 0805
SM 1206
SM 1206
SM 1206
SM 1206
SM 1206
SM 1210
6.9x6.5
H1044-00333-16V8020-T
H1046-00106-6R3V10-T
H1065-00105-50V10-T
H1065-00105-50V10-T
H1065-00106-25V10-T
H1065-00226-6R3V10-T
H1065-004R7-50VR25-T
H1082-00107-6R3V20-T
IHLP-2525CZ-ER-10R-M01 VISHAY
DNP (SP1)
0
DNP
-
-
-
131-5031-00
TEKTRONIX
TP1-TP10
TP11-TP17
D1
10
7
1
-
-
-
-
-
-
-
-
-
-
-
-
1514-2
5002
B340LB-13-F-T
KEYSTONE
KEYSTONE
DIODES INC
D3, D4
2
-
-
-
-
LTST-C170CKT
LITEON, VISHAY,
ROHM, STANLEY
ELECTRIC
INTERSIL
U1
Q1-Q5
1
5
-
-
-
-
-
60V
QFN
SOT-23
ISL8501IRZ
2N7002-7-F-T
TRANSISTOR, N-CHANNEL,
DIODES, INC, ON
SEMICONDUCTOR 3 LD,SOT-23, 60V, 115mA,
ROHS
AN1326 Rev 0.00
July 10, 2007
Page 4 of 9
ISL8501EVAL1Z
TABLE 2. COMPONENT LIST (Continued)
REF DES
R17, R18
R2, R11,
R13, R15
R12, R14,
R16
R1
R4
R9
R3
R6-R8
R5, R10,
R29
R21, R24
R20, R23
R25
R26-R28,
R30
SW1-SW3
C20, C21
D2
L1
QTY
2
4
3
1
1
1
1
3
3
2
2
1
0
3
0
0
0
VALUE
0
10k
100k
20k
2.21k
2.55k
301
5.11k
0
10k
2.43k
0
DNP
-
DNP
DNP
DNP
TOL
5%
1%
1%
1%
1%
1%
1%
1%
1%
1%
1%
1%
1%
-
-
-
-
VOLTAGE PACKAGE
50V
50V
50V
50V
50V
50V
50V
50V
75V
75V
75V
200V
200V
-
-
-
-
SM 0402
SM 0402
SM 0402
SM 0402
SM 0402
SM 0402
SM 0402
SM 0402
SM 0603
SM 0603
SM 0603
SM 1206
SM 1206
-
-
-
-
PART NUMBER
H2510-00R00-1/16W-T
H2510-01002-1/16W1-T
H2510-01003-1/16W1-T
H2510-02002-1/16W1-T
H2510-02211-1/16W1-T
H2510-02551-1/16W1-T
H2510-03010-1/16W1-T
H2510-05111-1/16W1-T
H2511-00R00-1/10W-T
H2511-01002-1/10W1-T
H2511-02431-1/10W1-T
H2513-00R00-1/4W-T
H2513-DNP
GT11MSCBE-T
DNP
DNP
DNP
MANUFACTURER
VENKEL,
PANSONIC
PANASONIC,
VENKEL
PANASONIC
PANASONIC
PANASONIC,
VENKEL
VENKEL, VISHAY,
DALE
PANASONIC,
VENKEL
PANASONIC
GENERIC
KOA, VENKEL
VENKEL, YAGEO
VISHAY, VENKEL
GENERIC
C&K
COMPONENTS
DESCRIPTION
RES, SMD, 0402, 0, 1/16W,
5%, TF, ROHS
RES, SMD, 0402, 10k, 1/16W,
1%, TF, ROHS
RES, SMD, 0402, 100k,
1/16W, 1%, TF, ROHS
RES, SMD, 0402, 20k, 1/16W,
1%, TF,ROHS
RES, SMD, 0402, 2.21k,
1/16W, 1%, TF, ROHS
RES, SMD, 0402, 2.55k,
1/16W, 1%, TF, ROHS
RES, SMD, 0402, 301,
1/16W, 1%, TF, ROHS
RES, SMD, 0402, 5.11k,
1/16W, 1%, TF, ROHS
RESISTOR, SMD, 0603,
0, 1/10W, TF, ROHS
RES, SMD, 0603, 10k, 1/10W,
1%, TF, ROHS
RES, SMD, 0603, 2.43k,
1/10W, 1%,TF, ROHS
RES, SMD, 1206, 0, 1/4W,
TF, ROHS
RES, SMD, 1206, DNP, DNP,
DNP, TF, ROHS
SWITCH-TOGGLE, SMD,
ULTRAMINI, 1P, SPST MINI
DO NOT POPULATE OR
PURCHASE
DO NOT POPULATE OR
PURCHASE
DO NOT POPULATE OR
PURCHASE
AN1326 Rev 0.00
July 10, 2007
Page 5 of 9
