an1912

Application Note 1912
Author: Sameer Dash
ISL91110IIN-EVZ, ISL91110II2A-EVZ, ISL91110IIA-EVZ
Evaluation Boards
Description
Key Board Features
The ISL91110 is a high-current buck-boost switching regulator
for systems using new battery chemistries. It uses Intersil’s
proprietary buck-boost algorithm to maintain voltage regulation,
while providing excellent efficiency and very low output voltage
ripple when the input voltage is close to the output voltage. The
ISL91110IIN-EVZ, ISL91110II2A-EVZ and ISL91110IIA-EVZ
platforms allow quick evaluation of the high performance
features of the ISL91110 buck-boost regulator series.
• Small, compact design
• Jumper selectable EN (enabled/disabled)
• Jumper selectable MODE (auto-PFM/forced-PWM)
• Connectors, test points, and jumpers for easy probing
References
• ISL91110 Data Sheet.
Specifications
Ordering Information
The boards are designed to operate at the following operating
conditions:
• Input voltage rating from 1.8V to 5.5V
PART NUMBER
• Resistor programmable output voltage on the ISL91110IIA-EVZ
• Fixed 3.3V output voltage on the ISL91110IIN-EVZ
• Fixed 3.5V output voltage on the ISL91110II2A-EVZ
• Up to 2A output current (PVIN = 2.5V, VOUT = 3.3V)
DESCRIPTION
ISL91110IIN-EVZ
Evaluation Board for ISL91110IINZ
ISL91110II2A-EVZ
Evaluation Board for ISL91110II2AZ
ISL91110IIA-EVZ
Evaluation Board for ISL91110IIAZ
• 2.5MHz switching frequency
• Operating temperature range: -40°C to +85°C
ISL91110IIAZ
VIN
GND
PVIN
LX1
VIN
LX2
VOUT
VOUT
MODE
FB
GND
PGND
SGND
EN
FIGURE 1. ISL91110IIA-EVZ BLOCK DIAGRAM
March 12, 2014
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1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2014. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
Application Note 1912
Functional description
The ISL91110IIN-EVZ, ISL91110II2A-EVZ and ISL91110IIA-EVZ
provides simple platforms to demonstrate the feature of the
ISL91110 buck-boost regulator. The ISL91110IIN-EVZ is for the
fixed 3.3V output IC ISL91110IINZ. The ISL91110II2A-EVZ is for
the fixed 3.5V output IC ISL91110II2AZ and the ISL91110IIA-EVZ
is for the adjustable output IC ISL91110IIAZ. The Evaluation
boards have been functionally optimized for best performance of
the ISL91110 IC series. The input power and load connections
are provided through multi-pin connectors for high current
operations.
The ISL91110IIA-EVZ evaluation board is shown in Figures 4 and 5.
The board’s enable function is controlled by the on-board jumper
header J3. Similarly the Mode function is controlled by the on-board
jumper header J4.
be connected to the VOUT and GND headers on J2. Measure
the input and output currents. Calculate efficiency based on
these measurements.
11. To test external sync, remove the jumper at J4, then apply an
external clock between 2.75MHz and 3.25MHz on the MODE
input (the center pin of header J4).
TABLE 1. OUTPUT VOLTAGE PROGRAMMING For ISL91110IIA-EVZ
DESIRED OUTPUT VOLTAGE
(V)
R2 RESISTOR VALUE
(kΩ)
2.0
665
2.5
470
3.0
365
3.3
324
3.4
309
4.0
249
4.5
215
5.0
191
The schematic of the ISL91110IIA-EVZ evaluation board is shown
in Figure 6. The schematic for the ISL91110IIN-EVZ and
ISL91110II2A-EVZ is shown in Figure 7. The PCB layout images
for all layers are shown in Figures 8 and 11. The bill of materials
of the ISL91110IIA-EVZ is shown in Table 2. The bill of materials
of the ISL91110IIN-EVZ and ISL91110II2A-EVZ is shown in
Table 3.
Operating Range
The VIN range of the boards is 1.8V to 5.5V. The VOUT range for the
ISL91110IIA-EVZ is 2V to 5V. The IOUT range of the boards is 0 to 2A.
The operating ambient temperature range is -40°C to +85°C.
Quick Start Guide
For the ISL91110IIA-EVZ board, the default output voltage is set
at 3.3V. Should other output voltages are desired, resistor R2 can
be changed to set to a desired voltage as shown in Table 1 (use a
resistor with 1% accuracy).
Refer to the following Quick Setup Guide to configure and
power-up the board for proper operation. During the power-on
process, the expected waveforms are shown in Figures 2 and 3.
LX1
2V/DIV
LX2
2V/DIV
VOUT
2V/DIV
EN
2V/DIV
IOUT = 200mA
400µs/DIV
Quick Setup Guide
1. Install jumper on J3, shorting EN to VIN.
FIGURE 2. ISL91110 START-UP WITH VIN = 2V and VOUT = 3.3V
2. Install jumper on J4, shorting MODE to VIN.
3. Connect power supply to J1, with voltage setting between
1.8V and 5.5V.
4. Connect electronic load to J2.
5. Place scope probes on the VOUT test point, and other test
points of interest.
LX1
2V/DIV
LX2
2V/DIV
6. Turn on the power supply.
7. Monitor the output voltage start-up sequence on the scope. The
waveforms will look similar to that shown in Figures 2 and 3.
VOUT
2V/DIV
8. Turn on the electronic load.
EN
2V/DIV
9. Measure the output voltage with the voltmeter. The voltage
should regulate within datasheet spec limits.
10. To determine efficiency, measure input and output voltages
at the Kelvin sense test points (S+ and S-), which are part of
J1 and J2 headers. The bench power supply can be connected
to the PVIN and GND headers on J1. The electronic load can
2
IOUT = 200mA
400µs/DIV
FIGURE 3. ISL91110 START-UP WITH VIN = 4V and VOUT = 3.3V
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Application Note 1912
ISL91110IIA-EVZ Evaluation Board
FIGURE 4. ISL91110IIA-EVZ TOP VIEW
FIGURE 5. ISL91110IIA-EVZ BOTTOM VIEW
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Application Note 1912
ISL91110IIA-EVZ Evaluation Board Schematic
FIGURE 6. ISL91110IIA-EVZ EVALUATION BOARD SCHEMATIC
TABLE 2. ISL91110IIA-EVZ EVALUATION BOARD BILL OF MATERIALS
ITEM#
QTY
DESIGNATORS
PART TYPE
FOOTPRINT
1
1
U1
ISL91110IIAZ
W4x5.20; WLCSP
Intersil ISL91110 Buck-Boost
Regulator with Adjustable Output
Voltage
INTERSIL
2
1
L1
1µH
3.2mmx2.5mmx1.2mm
Power Inductor Toko DFE322512C
series, 4.6A (typ), 34mΩ (typ)
TOKO
3
1
C1
330µF
7343
Capacitor, Tantalum
ANY
4
2
C2, C3
10µF/16V/X5R
0603
Capacitor, Generic
ANY
5
2
C4, C5
22µF/10V/X5R
0603
Capacitor, Generic
ANY
6
1
C6
56pF
0402
Capacitor, 56pF 50V 5% NP0 0402
ANY
7
1
C7
0.1µF
0402
Capacitor, Generic
ANY
8
1
R1
1.02MΩ, 1%
0402
Resistor, Generic
ANY
9
1
R2
324kΩ, 1%
0402
Resistor, Generic
ANY
10
2
R3, R4
1MΩ, 5%
0603
Resistor, Generic
ANY
11
2
J1, J2
HDR-6
HDR-6
Vert. Pin Header, 6-Pin, 0.1” Spacing,
Generic
ANY
12
2
J3, J4
HDR-3
HDR-3
Vert. Pin Header, 3-Pin, 0.1” Spacing,
Generic
ANY
13
3
TP1, TP2, TP3
SCOPE PROBE
SCOPE PROBE
4
DESCRIPTION
VENDORS
Test Point, Scope Probe 131-5031-00 TEKTRONIX
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Application Note 1912
ISL91110IIN-EVZ, ISL91110II2A-EVZ Evaluation Board Schematic
FIGURE 7. ISL91110IIN-EVZ, ISL91110II2A-EVZ EVALUATION BOARD SCHEMATIC
TABLE 3. ISL91110IIN-EVZ, ISL91110II2A-EVZ EVALUATION BOARD BILL OF MATERIALS
ITEM#
QTY
DESIGNATORS
PART TYPE
FOOTPRINT
DESCRIPTION
VENDORS
1
1
U1
ISL91110IINZ,
ISL91110II2AZ
W4x5.20; WLCSP
Intersil ISL91110 Buck-Boost Regulator
INTERSIL
2
1
L1
1µH
3
1
C1
330µF
7343
Capacitor, Tantalum
ANY
4
2
C2, C3
10µF/16V/X5R
0603
Capacitor, Generic
ANY
5
2
C4, C5
22µF/10V/X5R
0603
Capacitor, Generic
ANY
6
1
C6
DNP
0402
7
1
C7
0.1µF
0402
Capacitor, Generic
ANY
8
1
R1
0Ω
0402
Resistor, Generic
ANY
9
1
R2
DNP
0402
10
2
R3, R4
1MΩ, 5%
0603
Resistor, Generic
ANY
11
2
J1, J2
HDR-6
HDR-6
Vert. Pin Header, 6-Pin, 0.1” Spacing,
Generic
ANY
12
2
J3, J4
HDR-3
HDR-3
Vert. Pin Header, 3-Pin, 0.1” Spacing,
Generic
ANY
13
3
TP1, TP2, TP3
SCOPE PROBE
SCOPE PROBE
Test Point, Scope Probe 131-5031-00
TEKTRONIX
5
3.2mmx2.5mmx1.2mm Power Inductor Toko DFE322512C
series, 4.6A (typ), 34mΩ (typ)
TOKO
ANY
ANY
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Application Note 1912
PCB Layout
FIGURE 8. TOP LAYER
FIGURE 9. INNER LAYER 1
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Application Note 1912
PCB Layout (Continued)
FIGURE 10. INNER LAYER 2
FIGURE 11. BOTTOM LAYER
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
7
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