an1918

Application Note 1918
Sameer Dash
ISL91117II7-EVZ, ISL91117IIA-EVZ Evaluation Boards
Description
Key Board Features
The ISL91117 is a highly-integrated boost switching regulator
for battery powered applications. The device provides a power
supply solution for products using dual-cell or three-cell
alkaline, NiCd or NiMH, or one-cell Li-ion or Li-polymer battery
The ISL91117II7-EVZ and ISL91117IIA-EVZ platforms allow
quick evaluation of the high performance features of the
ISL91117 high current boost regulator series.
• Small, compact design
Specifications
ISL91117 Data Sheet.
• Jumper selectable EN (enabled/disabled)
• Jumper selectable MODE (auto-PFM/forced-PWM)
• Connectors, test points, and jumpers for easy probing
References
The boards are designed to operate at the following operating
conditions:
Ordering Information
• Input voltage rating from 1.8V to 4.8V
PART NUMBER
• Resistor programmable output voltage on the ISL91117IIA-EVZ
DESCRIPTION
• Fixed 5V output voltage on the ISL91117II7-EVZ
ISL91117II7-EVZ
Evaluation Board for ISL91117II7Z
• True disconnect input to output when disabled
ISL91117IIA-EVZ
Evaluation Board for ISL91117IIAZ
• Up to 1.5A output current (PVIN = 3.3V, VOUT = 5V)
• 2.5MHz switching frequency
• Operating temperature range: -40°C to +85°C
BLKG
VIN
LX
GND
VOUT
VIN
MODE
ISL91117IIAZ
PVIN
FB
VOUT
GND
PGND
SGND
EN
FIGURE 1. ISL91117IIA-EVZ BLOCK DIAGRAM
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Application Note 1918
Functional description
The ISL91117II7-EVZ and ISL91117IIA-EVZ evaluation boards
provide simple platforms to demonstrate the feature of the
ISL91117 high current boost regulator. The ISL91117II7-EVZ is
for the fixed 5V output IC ISL91117II7Z and the ISL91117IIA-EVZ
is for the adjustable output IC ISL91117IIAZ. The evaluation
boards have been functionally optimized for best performance of
the ISL91117 IC series. The input power and load connections
are provided through multi-pin connectors for high current
operations.
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).
12. Set the electronic load to constant current dynamic mode
with 10mA to 1A pulse, tON= 500µs. Check the load transient
response as shown in Figure 3.
TABLE 1. OUTPUT VOLTAGE PROGRAMMING For ISL91117IIA-EVZ
The ISL91117IIA-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.
DESIRED OUTPUT VOLTAGE
(V)
R1 RESISTOR VALUES
(kΩ)
2.0
90.9
The schematic of the ISL91117IIA-EVZ evaluation board is shown
in Figure 6. The schematic for the ISL91117II7-EVZ is shown in
Figure 7. The PCB layout images for all layers are shown in
Figures 8 through 11. The bill of materials of the ISL91117IIA-EVZ
is shown in Table 2. The bill of materials of the ISL91117II7-EVZ is
shown in Table 3.
2.5
127
3.0
165
3.3
187
3.6
210
4.0
243
4.5
280
5.0
316
Operating Range
The VIN range of the boards is 1.8V to 4.8V. The VOUT range for
the ISL91117IIA-EVZ is VIN+0.2V to 5V. The IOUT range of the
boards is 0 to 1.5A. The operating ambient temperature range is
-40°C to +85°C.
Quick Start Guide
EN (2V/DIV)
For the ISL91117IIA-EVZ board, the default output voltage is set
at 5V. Should other output voltages are desired, resistor R1 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.
Quick Setup Guide
VOUT (1V/DIV)
INDUCTOR CURRENT
(500mA/DIV)
1. Install jumper on J3, shorting EN to VIN.
2. Install jumper on J4, shorting MODE to VIN.
3. Connect power supply to J1, with voltage setting between
1.8V and 4.8V.
500µs/DIV
FIGURE 2. ISL91117 START-UP WITH VIN = 3.6V and VOUT = 5V
VIN (1V/DIV)
4. Connect electronic load to J2.
5. Place scope probes on the VOUT test point, and other test
points of interest.
6. Turn on the power supply.
VOUT, 5V OFFSET
(200mV/DIV)
7. Monitor the output voltage start-up sequence on the scope.
The waveforms will look similar to that shown in Figure 2.
10mA – 1A
LOAD TRANSIENT
(240mA/µs SLEW
RATE)
8. Turn on the electronic load.
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
be connected to the VOUT and GND headers on J2. Measure
2
INDUCTOR
CURRENT (1A/DIV)
200µs/DIV
FIGURE 3. ISL91117 LOAD TRANSIENT AT VIN = 3V AND VOUT = 5V
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Application Note 1918
ISL91117IIA-EVZ Evaluation Board
FIGURE 4. TOP VIEW
FIGURE 5. BOTTOM VIEW
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Application Note 1918
ISL91117IIA-EVZ Evaluation Board Schematic
FIGURE 6. ISL91117IIA-EVZ EVALUATION BOARD SCHEMATIC
TABLE 2. ISL91117IIA-EVZ EVALUATION BOARD BILL OF MATERIALS
ITEM#
QTY
DESIGNATORS
PART TYPE
1
1
U1
ISL91117IIAZ
2
1
L1
1µH
3.2mmx2.5mm
3
2
C1, C2
47µF/6.3V/
X5R
0805
Capacitor, GRM21BR60J476ME15L
4
1
C4
22pF
0402
Capacitor, Generic
ANY
5
1
R1
316kΩ, 1%
0402
Resistor, Generic
ANY
6
1
R2
60.4kΩ, 1%
0402
Resistor, Generic
ANY
7
2
J3, J4
HDR-3
HDR-3
Vert. Pin Header, 3-Pin, 0.1” Spacing, Generic
ANY
11
2
J1, J2
HDR-4
HDR-4
Vert. Pin Header, 4-Pin, 0.1” Spacing, Generic
ANY
12
9
TP1, TP2, TP4, TP5,
TP9, TP10, TP11,
TP13, TP14
TEST POINT
TEST POINT
4
FOOTPRINT
DESCRIPTION
W4x5.20; WLCSP Intersil ISL91117 Boost Regulator with
Adjustable Output Voltage
Power Inductor DFE322512C, 4.6A, 34mΩ
Test Point, Thru-Hole, 3156-1-00-15-00-00-08-0
VENDORS
INTERSIL
TOKO
MURATA
MILL-MAX PINS
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Application Note 1918
ISL91117II7-EVZ Evaluation Board Schematic
FIGURE 7. ISL91117II7-EVZ EVALUATION BOARD SCHEMATIC
TABLE 3. ISL91117II7-EVZ EVALUATION BOARD BILL OF MATERIALS
ITEM#
QTY
DESIGNATORS
PART TYPE
FOOTPRINT
DESCRIPTION
VENDORS
1
1
U1
ISL91117II7Z
W4x5.20
WLCSP
Intersil ISL91117 Boost Regulator with Fixed 5V
Output
INTERSIL
2
1
L1
1µH
3
2
C1, C2
47µF/6.3V/X5R
0805
Capacitor, GRM21BR60J476ME15L
4
1
C4
OPEN
0402
Not installed
ANY
5
1
R1
0Ω
0402
Resistor, Generic
ANY
6
1
R2
OPEN
0402
Not installed
ANY
7
2
J3, J4
HDR-3
HDR-3
Vert. Pin Header, 3-Pin, 0.1” Spacing, Generic
ANY
11
2
J1, J2
HDR-4
HDR-4
Vert. Pin Header, 4-Pin, 0.1” Spacing, Generic
ANY
12
9
TP1, TP2, TP4, TP5,
TP9, TP10, TP11,
TP13, TP14
TEST POINT
TEST POINT
5
3.2mmx2.5mm Power Inductor DFE322512C, 4.6A, 34mΩ
Test Point, Thru-Hole, 3156-1-00-15-00-00-08-0
TOKO
MURATA
MILL-MAX PINS
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Application Note 1918
PCB Layout
FIGURE 8. TOP LAYER
FIGURE 9. INNER LAYER 1
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Application Note 1918
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
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