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ISL8216MEVAL1Z Evaluation Board User’s Guide
Description
The ISL8216M is a simple and easy to use, high voltage DC/DC
module. The ISL8216M is ideal for servers, 48V
telecom/datacom applications, 12V/42V automotive and
industrial equipment, and other distributed power
converters/point-of-load (POL) applications. Only few passive
components and a VOUT setting resistor are needed for a
complete a high voltage power design.
The ISL8216MEVAL1Z provides an evaluation platform for the
ISL8216M. The input voltage range is from 10V to 80V, and the
output voltage is preset to five options, 5V, 12V, 20V, 24V and
30V. Any other output voltages within the range from 2.5V to
30V can be set with a single resistor.
Recommended Equipment
• 10V to 80V (or other voltage rating depending on desired
input voltage for the ISL8216M) power supply with at least
2A source current capability
• Electronic load capable of sinking current up to 4A
• Digital multimeters (DMMs)
• 100MHz quad-trace oscilloscope
Quick Start
1. Select the output voltage by using one of the five jumpers
JP1 to JP5, for 5V, 12V, 20V, 24V or 30V.
2. Connect the VIN (J1) and PGND (J2) terminals to a power
supply and connect the load to the VOUT (J4) and PGND (J3)
terminals.
3. Set the input power supply to desired input voltage between
10V to 80V; note that the input voltage must be higher than
the selected output voltage.
4. Enable the power supply first before turning on the load,
preset the load to 0A.
5. Toggle switch SW1 to the lower position denoted “ENABLE”.
The PGOOD INDICATOR LED should glow in green to indicate
proper operation. Use the digital multimeter to check the
output voltage.
FIGURE 1. ISL8216MEVAL1Z BOARD IMAGE
V VVOUT
LOAD
(0A to 4A) VIN 10V to 80V
+
-
+
-
VOUT SELECTION JUMPERS
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.
February 10, 2014
AN1907.0
Application Note 1907
Application Note 1907
2AN1907.0
February 10, 2014
Evaluation Board Information
The evaluation board size is 76.2mmx76.2mm (3 inchx3 inch).
The FR4 board has four layers, with 2oz copper on the top and
the bottom layers, and 1oz copper on the two internal layers. The
board can be used as 4A reference design. Refer to the
“ISL8216MEVAL1Z Board Schematic” on page 4 and
“ISL8216MEVAL1Z Layouts” on page 5. All the components on
the board, including the solder attachment, are lead free.
Circuits Description
Selecting Output Voltage
The ISL8216MEVAL1Z evaluation board has several output voltages
preset for user’s convenience. The 5V, 12V, 20V, 24V, and 30V can
be easily selected by shorting their appropriate jumper. If any other
output voltage between 2.5V and 30V is desired, the user can use a
feedback resistor based on Equation 1.
NOTE: The output voltage accuracy is not only dependent on the module’s
internal reference voltage, but also on the feedback resistance accuracy.
For higher overall output accuracy, the customer should select a high
accuracy resistor (i.e; 0.5%).
Programming the Switching Frequency
The ISL8216M has an internally set fixed switching frequency of
300kHz. By adding a resistor between VIN and RTCT and a
capacitor between RTCT and SGND, the module’s switching
frequency can be adjusted between 200kHz to 600kHz. The
place holders for the resistor (R5) and capacitor (C5) are provided
on the ISL8216MEVAL1Z evaluation board for the user’s
convenience. Refer to the ISL8216M datasheet for optimum
switching frequency for different conditions.
The SYNC pin can provide the function to synchronize the
ISL8216M’s switching frequency to an external source. When
frequency synchronization is used, the time constant of RT/CT
must be set longer than the period of the sync signal. When the
external sync feature is not used, the customer should tie the
SYNC pin to SGND.
Optional External Enable Control Circuit
The module can be enabled by an external signal by using an
open-drain device, or by adding an external circuit. This optional
external enable circuit is provided on the ISL8216MEVAL1Z
evaluation board, see Figure 2.
To utilize the circuit shown in Figure 2, the user can place
appropriate components on the place holders for R201, D201,
R202, Q201, and Q202.
A bias voltage of approximately 5.1V is generated from VIN with a
resistor (R201) in series and a zener diode (D201). R202 is a
pull-up resistor of typically 100kΩ, and Q201 and Q202 are
N-MOSFETs. The external control signal is applied to TP14
(EX_EN). When EX_EN is logic low, ENSS is pulled to ground to
disable the module. When EX_EN is logic high, ENSS is released
to allow the module’s soft-start function. The selection of R201 in
series with the zener diode D201 can be calculated as shown in
Equation 2:
Where:
•V
Z is the zener diode D201’s working voltage, nominal 5.1V.
•I
Z is the zener diode D201’s working reverse current, typically
about 5mA.
The power dissipation rating should be taken into consideration
when selecting R201.
Other External Circuits Requirements
Depending on the applications conditions, other external circuits
may be required. Table 1 shows these requirements.
VOUT 111.3k
RFB
----------------------------+


1.192V=(EQ. 1)
FIGURE 2. OPTIONAL EXTERNAL ENABLE CIRCUIT
ON/OFF
BIAS VOLTAGE
ENSS
R202
VIN
R201
D201
VOUT
Q201
Q202
Q203
EX_EN
TP14
(EQ. 2)
R201 VIN VZ
–
IZ
----------------------------=
TABLE 1. EXTERNAL CIRCUITS REQUIREMENT BASED ON APPLICATION CONDITIONS
CONDITIONS EXTERNAL CIRCUITS REQUIREMENTS
VOUT Use PGOOD Signal Enable Method PGOOD Delay Circuit 1kΩ Dummy Load Resistor VIN-BOOT Resistor
≤12V Yes/No Self or External Enable Control No No No
>12V Yes Self Enable Yes Yes No
>12V No Self Enable No No Yes
>12V Yes External Enable Control No No Yes
>12V No External Enable Control No No Yes
Application Note 1907
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February 10, 2014
Optional PGOOD Delay Circuit
The ISL8216M has a PGOOD comparator which monitors the
voltage on the FB pin. The PGOOD is asserted (open drain) when
the FB pin voltage is within 14% of the reference voltage. The
PGOOD is de-asserted under disable, overcurrent protection
event, or over-temperature event.
As described in Table 1, a PGOOD delay circuit, as well as a
dummy load resistor of 1kΩ, 1W rating, are required if all of the
following conditions are met:
•V
OUT is higher than 12V
• PGOOD signal is utilized
• Module is self enabled/disabled
The place holders for this PGOOD delay circuit (C2, R3 and M1)
and the dummy load resistor (R20) are provided on the
ISL8216MEVAL1Z evaluation board for the user’s convenience,
as shown in Figure 3, where C2 is 1µF, R3 is typically 150kΩ, and
M1 is an N-MOSFET. In the case where input voltage VIN is not
monotonic, an optional Schottky diode is recommended in
parallel with resistor R3, to ensure that the capacitor C2 has
been fully discharged when PVCC starts to rise from 0V.
For VOUT>12V and light load condition, if the optional PGOOD
delay circuit is not used during VIN ramp up, PGOOD logic can
malfunction due to low VOUT as a result of bootstrap capacitor not
being fully charged. This issue can be solved by adding a delay of
about 250ms with this optional delay circuit.
Resistor Between VIN and BOOT
As described in Table 1, a resistor between VIN and BOOT is
recommended if ANY of the following conditions are met:
•V
OUT is higher than 12V and PGOOD signal is not utilized.
•V
OUT is higher than 12V, PGOOD signal is utilized, and module
is enabled/disabled by an external control signal.
The place holder for this resistor, R23, is provided on the
ISL8216MEVAL1Z evaluation board for the user’s convenience.
Refer to the ISL8216M datasheet for the selection of this
resistor. A minimum 0.25W power rating is recommended for
this resistor.
An additional N-MOSFET along with the external enable circuit is
required when R23 is populated. This N-MOSFET is used for
pulling VOUT to ground when the external control signal is logic
low. Without this N-MOSFET, a residual voltage can be generated
on VOUT capacitors due to leakage from VIN, R23, internal
bootstrap diode, internal bootstrap capacitor, and inductor to
VOUT capacitor.
Output Capacitors
The 6x22µF ceramic capacitors with voltage rating of 35V have
been installed on the ISL8216MEVAL1Z evaluation board.
However, additional place holder to add more capacitors are
provided on the board for evaluating low ESR tantalum capacitor,
low ESR polymer capacitor, and low ESR aluminum electrolytic
capacitor. A minimum total output capacitance of 120µF with
low ESR is recommended.
PCOMPX Pin Configuration
Control loop is already compensated internally to provide
sufficient stability margins for applications with various types of
output capacitors. For all ceramic output capacitors, short the
PCOMPX pin to VOUT; a 0Ω resistor R1 is provided on the
evaluation board. For tantalum capacitors, polymer capacitors, or
aluminum electrolytic capacitors, change R1 to resistance of
lower than 1kΩ. The lower the total ESR, the lower the R1 value
should be.
Radiated Emission
The ISL8216M has been evaluated with respect to CISPR 22
radio disturbance limits class B. The radiated emission test was
performed with a simple input filter installed on the
ISL8216MEVAL1Z evaluation board, as shown in Figure 3.
Figure 15 and Figure 16 show the radiated emissions plots with
respect to the CISPR 22 radio disturbance limits class B at
typical operating conditions of 24VIN to 5VOUT at 4A and 24VIN to
12VOUT at 4A.
PVCC
PGOOD
R3 150k
C2 1µF M1
2N7002
D1
OPTIONAL
DIODE
FIGURE 3. OPTIONAL PGOOD DELAY CIRCUIT WITH DIODE
FIGURE 4. OPTIONAL INPUT FILTER FOR IMPROVED EMI
PERFORMANCE
VIN
2.2µF×4
VDD
10µF
100nH
INPU T FILTER
VIN
ISL8216M
Application Note 1907
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February 10, 2014
ISL8216MEVAL1Z Board Schematic
FIGURE 5. ISL8216MEVAL1Z BOARD SCHEMATIC
Application Note 1907
5AN1907.0
February 10, 2014
ISL8216MEVAL1Z Layouts
FIGURE 6. TOP SILK SCREEN
FIGURE 7. TOP LAYER COMPONENT SIDE
Application Note 1907
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February 10, 2014
FIGURE 8. LAYER 2
FIGURE 9. LAYER 3
ISL8216MEVAL1Z Layouts (Continued)
Application Note 1907
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February 10, 2014
FIGURE 10. BOTTOM LAYER SOLDER SIDE
FIGURE 11. BOTTOM SILK SCREEN
ISL8216MEVAL1Z Layouts (Continued)
Application Note 1907
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February 10, 2014
Bill of Materials
PART NUMBER REF DES QTY VALUE TOL. VOLTAGE POWER PACKAGE TYPE MANUFACTURER DESCRIPTION
H1046-00104-50V10-T C4 1 0.1µF 10% 50V 805 Various Multilayer Ceramic Capacitor
H1065-00106-25V10-T C12 1 10µF 10% 25V 1206 Various
H1082-00225-100V10-T C13-C16 4 2.2µF 10% 100V 1210 Various
100ME68AX C18 2 68µF 20% 100V THOLE Sun Electronic
Industries
Aluminum Electrolytic
Capacitor
EEV-FK1H221P C21 0 DNP SMD Aluminum Electrolytic
Capacitors - SMD
C3216X5R1V226M160AC-T C23-C28 6 22µF 20% 35V 1206 TDK Multilayer Ceramic Capacitor
16TQC68MYF C111, C112 0 DNP SMD Tantalum Capacitor - Polymer
SMD
108-0740-001 J1-J4 4 Johnson
Components
Banana Jack
69190-202HLF JP1-JP5 5 THOLE BERG/FCI Jumper
SSL-LXA3025IGC-TR LED1 1 SMD LUMEX 3mmx2.5mm Surface Mount
LED
2N7002-7-F-T Q1 1 SOT-23 Various N-Channel 60V 115mA
MOSFET
H2511-00R00-1/10W-T R1 1 0Ω1% 1/10W 603 Various Thick Film Chip Resistor
H2515-DNP R20 0 DNP 2512
H2511-03321-1/10W1-T R30, R31 2 3.32kΩ1% 1/10W 603 Various Thick Film Chip Resistor
H2511-01241-1/10W1-T RFB1 1 1.24kΩ1% 1/10W 603 Various Thick Film Chip Resistor
H2511-03481-1/10W1-T RFB2 1 3.48kΩ1% 1/10W 603 Various Thick Film Chip Resistor
H2511-07150-1/10W1-T RFB3 1 715Ω1% 1/10W 603 Various Thick Film Chip Resistor
H2511-05900-1/10W1-T RFB4 1 590Ω1% 1/10W 603 Various Thick Film Chip Resistor
H2511-04640-1/10W1-T RFB5 1 464Ω1% 1/10W 603 Various Thick Film Chip Resistor
GT11MCBE SW1 1 THOLE ITT CANNON SPDT Toggle Switch ROHS
5002 TP1, TP5-TP8, TP10, TP11,
TP14, TP15
9 Keystone Test Point White
ISL8216MIRZ U1 1 HDA Intersil 15mmx15m DC/DC Power
Module
Application Note 1907
9AN1907.0
February 10, 2014
Efficiency Performance
FIGURE 12. EFFICIENCY vs LOAD CURRENT (5VOUT AT 300kHz) FIGURE 13. EFFICIENCY vs LOAD CURRENT (12VOUT)
FIGURE 14. EFFICIENCY vs LOAD CURRENT (24VOUT)
50
55
60
65
70
75
80
85
90
95
100
0 1 2 3 4
24VIN TO 5VOUT 300kHz
36VIN TO 5VOUT 300kHz
48VIN TO 5VOUT 300kHz
EFFICIENCY (%)
LOAD CURRENT (A)
60
65
70
75
80
85
90
95
100
0 1 2 3 4
80VIN TO 12VOUT 350kHz
64VINTO 12VOUT 350kHz
36VIN TO 12VOUT 400kHz
48VIN TO 12VOUT 400kHz
24VIN TO 12VOUT 400kHz
EFFICIENCY (%)
LOAD CURRENT (A)
60
65
70
75
80
85
90
95
100
0 1 2 3 4
EFFICIENCY (%)
LOAD CURRENT (A)
80 VIN TO 24VOUT 350kHz
48VIN TO 24VOUT 450kHz
64VIN TO 24VOUT 400kHz
Application Note 1907
10
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
AN1907.0
February 10, 2014
Radiated Emission Performance
FIGURE 15. RADIATED EMISSION AT 24VIN 5VOUT 4A
FIGURE 16. RADIATED EMISSION AT 24VIN 12VOUT 4A
CISPR 22 CLASS B
CISPR 22 CLASS B
Mouser Electronics
Authorized Distributor
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