Intersil ISL8107EVAL2Z Installation and operating instructions

1
®
AN1459.0
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.
ISL8107EVAL2Z
Introduction
The ISL8107 is a single-phase PWM controller that operates
from 9V to 75V bias supply voltage. The PWM controller
drives an external high-side N-Channel MOSFET in a
non-synchronous buck converter topology. The ISL8107
features input voltage feed-forward compensation and
overcurrent protection, etc. For a more detailed description
of the ISL8107 functionality, refer to the ISL8107 Data Sheet
http://www.intersil.com/data/fn/fn6605.pdf.
The ISL8107EVAL2Z Reference Design
The ISL8107EVAL2Z evaluation board is designed to meet
the output voltage and current specifications shown in
Table 1. Schematic, bill of materials, and layout plots are
included.
Quick Start Evaluation
Figure 1 shows a photograph of the ISL8107EVAL2Z board.
Circuit Setup
The input supply of the power stage can be connected to the
terminals P5 (VIN) and P6 (PGND). For single supply
application, the ISL8107’s bias supply can be tied to VIN
through J1 with shunt between pins 2 and 3. When using
separate supplies, provide the ISL8107 bias voltage through
P1 (VBIAS) with J1’s shunt between pins 1 and 2. The load
can be connected to terminal P7 (VOUT) and P8 (PGND).
TP3 and TP4 can be used for DMM to measure the output
voltage. Enabling and disabling the controller can be done
through the toggle switch, SW1.
ISL8107EVAL2Z Performance
Start-Up
Figure 2 shows the start-up waveforms of the
ISL8107EVAL2Z. Upon the VCC and VFF exceeding their
rising POR thresholds, the ISL8107 provides initially 2µA to
charge the soft-start capacitor, CSS, connected to the ENSS
pin. If the voltage at this pin is allowed to rise (the toggle
switch, SW1, at ON position), the voltage on ENSS pin will
ramp-up with at a slope determined by the 2µA current and
the value of the soft-start capacitor. When the voltage at
ENSS reaches 0.77V, the oscillator circuit is active, and
generates sawtooth waveform. At the same time, the
soft-start current is increased to 33µA; the ENSS voltage
then ramps up at a faster rate. The UGATE starts switching
when the ENSS voltage reaches 1.4V (Typ).
TABLE 1. ISL8107EVAL2Z DESIGN PARAMETERS
PARAMETER MIN TYP MAX
Input Voltage (VIN) 18V 48V 75V
Output Voltage (VOUT) 12V
Output Voltage Ripple 30mV
Continuous Load Current 5A
Switching Frequency 200kHz
FIGURE 1. ISL8107EVAL2Z FIGURE 2. START-UP WAVEFORMS
VOUT
ENSS
PHASE
PGOOD
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Output Voltage Ripple
Figure 3 shows the ripple voltage on the output of the
regulator at 5A load current.
Transient Responses
Figures 4, 5, and 6 show the response of the output when
subjected to transient loading from 1A to 5A at 1A/µs (within
continuous conduction mode).
Figure 7 shows the response of the output when subjected
to transient loading from 0.1A to 5A at 1A/µs (transition
between continuous conduction mode and discontinuous
conduction mode).
Efficiency and Line Regulation
The efficiency and the line regulation of the evaluation board
with various input voltages are shown in Figures 8 and 9,
respectively.
FIGURE 3. OUTPUT VOLTAGE RIPPLE @ IOUT = 5A
VOUT
FIGURE 4. OUTPUT TRANSIENT
VOUT
FIGURE 5. OUTPUT TRANSIENT
VOUT
PHASE
FIGURE 6. OUTPUT TRANSIENT
VOUT
PHASE
FIGURE 7. OUTPUT TRANSIENT
VOUT
FIGURE 8. CONVERTER EFFICIENCY (VOUT = 12V)
70
75
80
85
90
95
100
0123456
LOAD CURRENT (A)
EFFIECIENCY (%)
VIN = 18V
VIN = 24V
VIN = 36V
VIN = 48V
VIN = 60V
Application Note 1459

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FIGURE 9. LINE REGULATION FOR VOUT = 12V
12.000
12.010
12.020
12.030
12.040
12.050
12.060
12.070
12.080
12.090
12.100
0123456
LOAD CURRENT (A)
OUTPUT VOLTAGE (V)
VIN = 18V
VIN = 24V
VIN = 36V
VIN = 48V
VIN = 60V
Application Note 1459

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June 9, 2009
Application Note 1459
ISL8107EVAL2Z Schematic
TGATE
BOOT
GND
PGND
SYNC
PGND
PVCC
SGND
FB
VBG
Vreg
ENSS
VIN
Vreg
RT/CT
PHASE
PGOOD
OCSET VBIAS VFF
COMP
VOUT
PVCC
PGOOD
PVCC
P6
GND
P6
GND
1
R3
442
R3
442
C18
DNP
C18
DNP
1 2
R7
10
R7
10
C13
0.01uF
C13
0.01uF
1 2
C1
8.2nF
C1
8.2nF
1 2
C10
0.1uF
C10
0.1uF
1 2
SW1SW1
TP2TP2
R8
0
R8
0
J1J1
1
2
3
R20
1k
R20
1k
Q2
DNP
Q2
DNP
R13
10K
R13
10K
C14
1uF
C14
1uF
1 2
R12
DNP
R12
DNP
P4
SYNC
P4
SYNC
1
P3
GND
P3
GND
1
D1
V10P10
D1
V10P10
R14
0
R14
0
C24
1uF
C24
1uF
1 2
C29
DNP
C29
DNP
1 2
C27
1000pF
C27
1000pF
1 2
D3
MMBD1204/SOT
D3
MMBD1204/SOT
C7
1uF
C7
1uF
1 2
C17
100uF
100V
C17
100uF
100V
12
C9
1uF
C9
1uF
1 2
R17
1k
R17
1k
R11
0
R11
0
C20
DNP
C20
DNP
12
D4D4
2 1
C26
1uF
C26
1uF
1 2
C23
1uF
C23
1uF
1 2
R9
0
R9
0
Q3
BSS123LT1
Q3
BSS123LT1
2
1
3
Q1
HAT2175H
Q1
HAT2175H
C12
1uF
C12
1uF
1 2
C11
DNP
C11
DNP
12
C15
1uF
C15
1uF
1 2
R15
0
R15
0
P7
Vout
P7
Vout
1
C4
0.22uF
C4
0.22uF
1 2
L1
22uH
L1
22uH
1 2
P2
GND
P2
GND
1
P5
Vin
P5
Vin
1
R2
20k
R2
20k
C22
150uF
C22
150uF
12
C3
6.8nF
C3
6.8nF
1 2
R1
11.3k
R1
11.3k
R5
40.2k
R5
40.2k R16
0
R16
0
C25
1uF
C25
1uF
1 2
TP1TP1
C6
DNP
C6
DNP
1 2
C21
150uF
C21
150uF
12
TP3TP3
C2
82pF
C2
82pF
1 2
D2
DNP
D2
DNP
C30
DNP
C30
DNP
1 2
P1
VBias
P1
VBias
1
C19
DNP
C19
DNP
12
C8
100pF
C8
100pF
1 2
P8
GND
P8
GND
1
TP4TP4
C28
DNP
C28
DNP
1 2
R19
DNP
R19
DNP
C5
1000pF
C5
1000pF
1 2
C16
100uF
100V
C16
100uF
100V
12
R4
1.24k
R4
1.24k
U1
ISL8107
U1
ISL8107
VFF 1
OCSET 2
SYNC 4
RTCT
5
TGATE 14
VBG
9
PGOOD
10
COMP
8
PGND
11
PHASE 13
BOOT 15
VBIAS 3
SGND
6
PVCC 16
FB
7
ENSS
12
EP
17
R10
0
R10
0
R6
3.16k
R6
3.16k
R18
10K
R18
10K
Iaefgaeg

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Bill of Materials
REFERENCE QTY PART NUMBER DESCRIPTION PACKAGE VENDOR
U1 1 ISL8107IRZ Single PWM Controller 16 Ld QFN Intersil
Q1 1 HAT2175 100V N-Channel MOSFET LFPAK Renesas
Q3 1 BSS123LT1G N-Channel MOSFET, 0.17A SOT-23 On Semi.
D1 1 V10P10 100V Schottky Diode Rectifier TO-277A Vishay
D3 1 MMBD1204 100V Ultrafast Diode SOT-23 Fairchild
D4 1 597-3311 LED Green SMD1206 DIALIGHT
L1 1 HC9-220-R 22µH Power Inductor SMD 12.9x13.2 Coiltronics
Q2, D2 0 DNP
CAPACITORS
C1 1 8200pF, 50V, X7R, 10%, Ceramic Capacitor 0603 Various
C2 1 82pF, 50V, COG, 10%, Ceramic Capacitor 0603 Various
C3 1 6800pF, 50V, X7R, 10%, Ceramic Capacitor 0603 Various
C4 1 0.22µF, 16V, X7R, 10%, Ceramic Capacitor 0603 Various
C5 1 GRM2195C2A102JA01D 1000pF, 100V, COG, 5%, Ceramic Capacitor 0805 Murata
C7, C9, C14, C15 4 1µF, 100V, X7R, 10%, Ceramic Capacitor 1210 Various
C8 1 100pF, 50V, COG, 10%, Ceramic Capacitor 0603 Various
C10 1 0.1µF, 50V, X7R, 10%, Ceramic Capacitor 0603 Various
C12, C23, C24, C25, C26 5 1µF, 25V, X5R, 10%, Ceramic Capacitor 0805 Various
C13 1 0.01µF, 50V, X7R, 10%, Ceramic Capacitor 0603 Various
C16, C17 2 100ME100PX 100µF, 100V, Aluminum Electrolytic Capacitor RAD 12.5x20 Sanyo
C21, C22 2 20SEQP150M 150µF, 20V, OSCON Capacitor RAD 10x13 Sanyo
C27 1 1000pF, 50V, X7R, 10%, Ceramic Capacitor 0603 Various
C6, C11, C18, C19, C20,
C28, C29, C30 0DNP
RESISTORS
R1 1 Resistor, 11.3kΩ, 1%, 1/10W 0603 Various
R2 1 Resistor, 20kΩ, 1%, 1/10W 0603 Various
R3 1 Resistor, 442Ω, 1%, 1/10W 0603 Various
R4 1 Resistor, 1.24kΩ, 1%, 1/10W 0603 Various
R5 1 Resistor, 40.2kΩ, 1%, 1/10W 0603 Various
R6 1 Resistor, 3.16kΩ, 1%, 1/10W 0603 Various
R7 1 Resistor, 10Ω, 1%, 1/10W 0603 Various
R8, R9, R10, R11, R14,
R15, R16 70ΩResistor, 1/10W 0603 Various
R13, R18 2 Resistor, 10kΩ, 5%, 1/10W 0603 Various
R17 1 Resistor, 1kΩ, 1%, 1/10W 0603 Various
R20 1 Resistor, 1kΩ, 1%, 1W 2512 Various
R12, R19 0 DNP
OTHERS
J1 1 68000-236-1X3 Connector Header BERG/FCI
SW1 1 GT11MSCKE SMD Toggle Switch C&K
P1 through P8 8 1514-2 Turret Post Keystone
Application Note 1459

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ISL8107EVAL2Z Layout
FIGURE 10. TOP SILK SCREEN
FIGURE 11. TOP ASSEMBLY
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ISL8107EVAL2Z Layout(Continued)
FIGURE 12. TOP LAYER
FIGURE 13. LAYER 2
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ISL8107EVAL2Z Layout(Continued)
FIGURE 14. LAYER 3
FIGURE 15. BOTTOM LAYER
Application Note 1459

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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
AN1459.0
June 9, 2009
ISL8107EVAL2Z Layout(Continued)
FIGURE 16. BOTTOM SILK SCREEN
Application Note 1459