MIC28304 Evaluation Board
70V 3A Power Module
Hyper Speed Control™ Family
General Description
Getting Started
The Micrel MIC28304 is synchronous step-down regulator
module, featuring a unique adaptive ON-time control
architecture. The module incorporates a DC-to-DC
controller, power MOSFETs, bootstrap diode, bootstrap
capacitor, and an inductor in a single package. The
MIC28304 operates over an input supply range of 4.5V to
70V and can be used to supply up to 3A of output current.
The output voltage is adjustable down to 0.8V with a
guaranteed accuracy of ±1%. The device operates with a
programmable switching frequency from 200kHz to
600kHz.
1. VIN Supply
Connect a supply to the VIN and GND terminals,
paying careful attention to the polarity and the supply
range (7V < VIN < 70V). Monitor IIN with a current
meter and monitor input voltage at VIN and GND
terminals with a voltmeter. Do not apply power until
step 4.
®
The MIC28304-1 has the HyperLight Load architecture,
so it can operate in pulse skipping mode at light load.
However, it operates in fixed frequency CCM mode from
medium load to heavy load. The MIC28304-2 has Hyper
Speed Control™ architecture, which operates in fixed
frequency CCM mode under all load conditions.
The basic parameters of the evaluation board are:
•
Input: 7V to 70V
•
Output: 0.8V to 5V at 3A(1)
•
600kHz Switching Frequency (Adjustable 200kHz
to 600kHz)
2. Connect Load and Monitor Output
Connect a load to the VOUT and GND terminals. The
load can be either a passive (resistive) or an active (as
in an electronic load) type. A current meter may be
placed between the VOUT terminal and load to
monitor the output current. Ensure the output voltage
is monitored at the VOUT terminal.
3. Enable Input
The EN pin has an on board 100kΩ pull-up resistor
(R16) to VIN, which allows the output to be turned on
when PVDD exceeds its UVLO threshold. An EN
connector is provided on the evaluation board for
users to easily access the enable feature. Applying an
external logic signal on the EN pin to pull it low or
using a jumper to short the EN pin to GND will shut off
the output of the MIC28304 evaluation board.
Note:
1. Refer to temperature curves shown in the MIC28304 0.8V to 5V/3A
Evaluation Board Typical Characteristics section.
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Requirements
The MIC28304-1 and MIC28304-2 evaluation board
requires only a single power supply with at least 10A
current capability. No external linear regulator is required
to power the internal biasing of the IC because the
MIC28304 has internal PVDD LDO. In the applications
with VIN < +5.5V, PVDD should be tied to VIN to bypass
the internal linear regulator. The output load can either be
a passive or an active load.
Precautions
The MIC28304 evaluation board does not have reverse
polarity protection. Applying a negative voltage to the VIN
and GND terminals may damage the device. The
maximum VIN of the board is rated at 70V. Exceeding 70V
on the VIN could damage the device.
4. Turn Power
Turn on the VIN supply and verify that the output
voltage is regulated to 5V.
Ordering Information
Part Number
Description
MIC28304-1 5V EV
MIC28304-1 Evaluation
Board up to 5V Output
MIC28304-2 5V EV
MIC28304-2 Evaluation
Board up to 5V Output
MIC28304-1 12V EV
MIC28304-1 Evaluation
Board 12V Output
MIC28304-2 12V EV
MIC28304-2 Evaluation
Board 12V Output
Hyper LightLoad is a registered trademark and Hyper Speed Control is a trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
April 29, 2014
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
gives a 0.8V output voltage. All other voltages not listed
above can be set by modifying RBOTTOM value according to:
Features
Feedback Resistors
The output voltage on the MIC28304 evaluation board,
which is preset to 5.0V, is determined by the feedback
divider:
VOUT
R1
= VREF × 1 +
RBOTTOM
RBOTTOM =
R1× VREF
VOUT − VREF
Eq. 2
Note that the output voltage should not be set to exceed
5V due to the 6.3V voltage rating on the output capacitors.
For higher output voltage, use the Ordering Information
table. Table 1 gives the typical values of some of the
components, for details refer to Bill of Material table.
Eq. 1
where VREF = 0.8V, and RBOTTOM is one of R10, or R11,
which corresponds to 3.3V, 5V. Leaving the RBOTTOM open
Table 1. Typical Values of Some Components
VOUT
VIN
R3
(Rinj)
R1
(Top Feedback Resistor)
R11
(Bottom Feedback Resistor)
C10
(Cinj)
C12
(Cff)
0.9V
5V to 70V
16.5kΩ
10kΩ
80.6kΩ
0.1µF
2.2nF
47µF /6.3V
or 2 x 22µF
1.2V
5V to 70V
16.5kΩ
10kΩ
20kΩ
0.1µF
2.2nF
47µF /6.3V
or 2 x 22µF
1.8V
5V to 70V
16.5kΩ
10kΩ
8.06kΩ
0.1µF
2.2nF
47µF /6.3V
or 2 x 22µF
2.5V
5V to 70V
16.5kΩ
10kΩ
4.75kΩ
0.1µF
2.2nF
47µF /6.3V
or 2 x 22µF
3.3V
5V to 70V
16.5kΩ
10kΩ
3.24kΩ
0.1µF
2.2nF
47µF /6.3V
or 2 x 22µF
5V
7V to 70V
16.5kΩ
10kΩ
1.9kΩ
0.1µF
2.2nF
47µF/6.3V
or 2 x 22µF
12V
18V to 70V
23.2kΩ
10kΩ
715Ω
0.1µF
2.2nF
47µF/16V
or 2 x 22µF
April 29, 2014
2
COUT
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
The short circuit current limit can be programmed by using
the following formula:
SW Node
Test point J1 (VSW) is placed for monitoring the switching
waveform, which is one of the most critical waveforms for
the converter.
R15 =
Current Limit
The MIC28304 uses the RDS(ON) of the low-side MOSFET
and external resistor connected from the ILIM pin to the
SW node to decide the current limit.
RDS(ON) = On-resistance of low-side power MOSFET, 57mΩ
typically
VCL = Current-limit threshold (typical absolute value is
14mV per Electrical Characteristics Table in MIC28304
data sheet)
BST
ICL = Current-limit source current (typical value is 80µA,
per the Electrical Characteristics table).
SW
CS
ΔIL(PP) = Inductor current peak-to-peak, since the inductor
is integrated use Equation 4 to calculate the inductor ripple
current.
VIN
2.2µF
x2
SW
R15
The peak-to-peak inductor current ripple is:
ILIM
C6
∆IL(PP) =
FB
PGND
VOUT × (VIN(max) − VOUT )
Eq. 4
VIN(max) × fsw × L
The MIC28304 has 4.7µH inductor integrated into the
module. The typical value of RWINDING(DCR) of this particular
inductor is in the range of 45mΩ.
Figure 1. MIC28304 Current Limiting Circuit
In case of hard short, the short limit is folded down to allow
an indefinite hard short on the output without any
destructive effect. It is mandatory to make sure that the
inductor current used to charge the output capacitance
during soft start is under the folded short limit; otherwise
the supply will go in hiccup mode and may not be finishing
the soft start successfully.
In each switching cycle of the MIC28304, the inductor
current is sensed by monitoring the low-side MOSFET in
the OFF period. The sensed voltage V(ILIM) is compared
with the power ground (PGND) after a blanking time of
150ns. In this way the drop voltage over the resistor R15
(VCL) is compared with the drop over the bottom FET
generating the short current limit. The small capacitor (C6)
connected from ILIM pin to PGND filters the switching
node ringing during the off-time allowing a better short limit
measurement. The time constant created by R15 and C6
should be much less than the minimum off time.
The MOSFET RDS(ON) varies 30 to 40% with temperature.
Therefore, it is recommended to add a 50% margin to ICLIM
in the above equation to avoid false current limiting due to
increased MOSFET junction temperature rise. The
following table shows typical output current limit value for a
given R15 with C6 = 10pF.
The VCL drop allows programming of short limit through the
value of the resistor (R15), If the absolute value of the
voltage drop on the bottom FET is greater than VCL. In that
case the V(ILIM) is lower than PGND and a short circuit
event is triggered. A hiccup cycle to treat the short event is
generated. The hiccup sequence including the soft start
reduces the stress on the switching FETs and protects the
load and supply for severe short conditions.
April 29, 2014
Eq. 3
ICL
ICLIM = Desired current limit
MIC28304
VIN
(ICLIM − ∆IL (PP ) × 0.5) × R DS(ON) + VCL
3
R15
Typical Output Current Limit
1.81kΩ
3A
2.7kΩ
6.3A
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
Loop Gain Measurement
Resistor R14 is placed in series with the regulator
feedback path. The control loop gain can be measured by
connecting an impedance analyzer across the resistor and
selecting the resistor value in between 20Ω to 50Ω.
The following formula gives the estimated switching
frequency:
Setting the Switching Frequency
The MIC28304 switching frequency can be adjusted by
changing the value of resistor R19. The top resistor of
100kΩ is internal to module and is connected between VIN
and FREQ pin, so the value of R19 sets the switching
frequency. The switching frequency also depends on VIN,
VOUT and load conditions.
Where fO = Switching Frequency when R19 is open. For a
more precise setting, it is recommended to use the
following graph:
fSW _ ADJ = fO ×
R19
R19 + 100kΩ
Eq. 5
Switching Frequency
800
700
VIN = 12V
SW FREQ (kHz)
600
MIC28304
BST
500
VIN = 48V
400
300
200
VIN
VIN
100
RFREQ
2.2µF
x2
FREQ
100kΩ
SW
CS
0
10.00
VOUT = 5V
IOUT = 2A
100.00
1000.00
10000.00
R19 (kΩ)
R19
FB
Figure 3. Switching Frequency vs. R19
PGND
Figure 2. Switching Frequency Adjustment
April 29, 2014
4
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 0.8V to 5V/3A Evaluation Board Typical Characteristics
Efficiency (VIN = 12V)
vs. Output Current (MIC28304-1)
Efficiency (VIN = 18V)
vs. Output Current (MIC28304-1)
100
90
90
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
70
60
90
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
80
EFFICIENCY (%)
50
40
70
60
50
40
30
30
FSW = 600kHz
CCM
10
0.01
0.1
1
10
0.01
0.1
OUTPUT CURRENT (A)
Efficiency (VIN =12V)
vs. Output Current (MIC28304-2)
90
60
50
Efficiency (VIN = 24V)
vs. Output Current (MIC28304-2)
100
FSW = 600kHz
90
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
80
50
1
1.5
2
2.5
3
3.5
60
50
40
0
4
0.5
1
1.5
2
2.5
3
3.5
30
4
0
Thermal Derating
Thermal Derating
VOUT = 3.3V
FSW = 600kHz
MIC28304-2
Tj_MAX = 125°C
VIN = 24V
1
LOAD CURRENT (A)
VIN = 48V
2
VIN = 18V
55
70
85
MAXIMUM AMBIENT TEMPERATURE
(°C)
100
3
3.5
4
VIN = 48V
VIN = 24V
1
VIN = 12V
2
VIN =18V
VIN = 48V
VIN = 24V
1
VIN = 70V
VIN = 70V
40
2.5
VOUT = 2.5V
FSW = 600kHz
MIC28304-2
Tj_MAX = 125°C
VIN = 12V
0
0
25
2
Thermal Derating
VIN = 70V
0
1.5
3
VIN = 12V
VIN = 18V
1
OUTPUT CURRENT (A)
3
3
2
0.5
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
VOUT = 5V
FSW = 600kHz
MIC28304-2
Tj_MAX = 125°C
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
70
30
0.5
10
Efficiency (VIN = 18V)
vs. Output Current (MIC28304-2)
40
0
1
OUTPUT CURRENT (A)
60
30
0.1
OUTPUT CURRENT (A)
70
40
FSW = 600kHz
CCM
10
0.01
10
80
EFFICIENCY (%)
EFFICIENCY (%)
70
0.8V
40
90
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
80
1
FSW = 600kHz
FSW = 600kHz
1.2V
50
20
100
100
60
30
FSW = 600kHz
CCM
20
10
5.0V
3.3V
2.5V
1.8V
70
EFFICIENCY (%)
20
LOAD CURRENT (A)
80
LOAD CURRENT (A)
EFFICIENCY (%)
80
100
EFFICIENCY (%)
100
Efficiency (VIN = 24V)
vs. Output Current (MIC28304-1)
25
40
55
70
85
MAXIMUM AMBIENT TEMPERATURE
(°C)
100
25
40
55
70
85
100
MAXIMUM AMBIENT TEMPERATURE
(°C)
Die Temperature* : The temperature measurement was taken at the hottest point on the MIC28304 case mounted on a 5 square inch 4 layer, 0.62”,
FR-4 PCB with 2oz. finish copper weight per layer. Actual results will depend upon the size of the PCB, ambient temperature and proximity to other heat
emitting components.
April 29, 2014
5
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 0.8V to 5V/3A Output Evaluation Board Schematic
Figure 4. Schematic of MIC28304 Evaluation Board
(J1, J8, J10, J11, J12, J13, R14, R20, and R21 are for testing purposes)
April 29, 2014
6
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 0.8V to 5V/3A Output Evaluation Board Schematic (Continued)
Figure 5. Schematic of MIC28304 Evaluation Board
(Optimized for Smallest Footprint)
April 29, 2014
7
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
Bill of Materials 0.8V to 5V/3A Output
Item
C1, C1A
Part Number
(2)
EEU-FC2A101
GRM32ER72A225K
C2, C3, C2A(2),
(2)
C3A
C6, C6A(2)
12101C225KAT2A
AVX
GCM1885C2A100JA16D
Murata
C10, C17,
C10A(2),
(2)
C17A
C1608X5R0J105K
TDK
C1608X7S2A104K
GRM188R72A102KA01D
C11, C11A
C12, C12A
C14, C14A(2)
C16, C16A
AVX
Murata
TDK
4
10pF, 100V, 0603, NPO
2
1µF/6.3V Ceramic Capacitor, X7R, Size 0603
2
0.47µF/100V Ceramic Capacitor, X7R, Size 0805
2
4
0.1µF/100V, X7S, 0603
1nF/100V Ceramic Capacitor, X7R, Size 0603
2
2.2nF/100V Ceramic Capacitor, X7R, Size 0603
2
47µF/6.3V Ceramic Capacitor, X5R, Size 1210
2
0.1µF/6.3V Ceramic Capacitor, X7R, Size 0603
2
Murata
06031C222KAT2A
AVX
C1608X7R2A222K
TDK
12106D476MAT2A
2.2µF/100V Ceramic Capacitor, X7R, Size 1210
Murata
C1608X7R2A102K
GRM31CR60J476ME19K
2
0.1µF/100V Ceramic Capacitor, X7R, Size 0603
TDK
AVX
GRM188R71H104KA93D
(2)
Murata
06031C102KAT2A
GRM188R72A222KA01D
(2)
100µF Aluminum Capacitor, 100V
Murata
AVX
GRM188R72A104KA35D
(2)
AVX
06036C105KAT2A
08051C474KAT2A
Qty
Murata
(6)
GRM21BR72A474KA73
C9, C9A(2)
Description
(3)
(4)
TDK(5)
GRM188R70J105KA01D
C8, C8A
Panasonic
C3225X7R2A225K
06031A100JAT2A
(2)
Manufacturer
Murata
AVX
Murata
06035C104KAT2A
AVX
C1608X7R1H104K
TDK
C4, C5, C7,
C13, C15,
C4A(2), C7A(2),
(2)
C15A
DNP
Notes:
2. Either reference designator, that is, a reference designator ending with “A” or ending without “A,” can be used as part of customer design.
3. Panasonic: www.panasonic.com.
4. Murata: www.murata.com.
5. TDK: www.tdk.com.
6. AVX: www.avx.com.
April 29, 2014
8
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
Bill of Materials 0.8V to 5V/3A Output (Continued)
Item
Part Number
Manufacturer
Description
R1, R1A(2)
CRCW060310K0FKEA
Vishay Dale(7)
10kΩ Resistor, Size 0603, 1%
2
R2, R2A(2)
CRCW08051R21FKEA
Vishay Dale
1.21Ω Resistor, Size 0805, 5%
2
CRCW06031652F
Vishay Dale
16.5kΩ Resistor, Size 0603, 1%
2
CRCW06033K24FKEA
Vishay Dale
3.24kΩ Resistor, Size 0603, 1%
1
CRCW06031K91FKEA
Vishay Dale
1.91kΩ Resistor, Size 0603, 1%
2
CRCW0603715R0FKEA
Vishay Dale
715Ω Resistor, Size 0603, 1%
R3, R3A
(2)
R10,
R11, R11A
(2)
R12
(2)
R14, R20, R20A
Qty
DNP
CRCW06030000FKEA
Vishay Dale
0Ω Resistor, Size 0603, 5%
3
R15, R15A
(2)
CRCW04022K70JNED
Vishay Dale
2.7kΩ Resistor, Size 0603, 1%
2
R16, R16A
(2)
CRCW0603100KFKEAHP
Vishay Dale
100kΩ Resistor, Size 0603, 1%
2
R18, R18A
(2)
CRCW060349K9FKEA
Vishay Dale
49.9kΩ Resistor, Size 0603, 1%
2
CRCW060349R9FKEA
Vishay Dale
49.9Ω Resistor, Size 0603, 1%
1
CRCW06031R21FKEA
Vishay Dale
1.21Ω Resistor, Size 0603, 1%
2
R21
R23, R23A
(2)
R4, R19, R19A
(2)
U1, U1A(2)
DNP
MIC28304-1YMP
MIC28304-2YMP
Micrel. Inc.(8)
70V, 3A Power Module
2
Notes:
7. Vishay: www.vishay.com.
8. Micrel, Inc.: www.micrel.com.
April 29, 2014
9
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 0.8V to 12V/3A Evaluation Board Typical Characteristics
Efficiency
vs. Output Current (MIC28304-1)
Efficiency
vs. Output Current (MIC28304-2)
100
18VIN
4
100
95
VOUT = 12V
FSW=600kHz
MIC28304-2
R3=23.2k
Tj_MAX =125°C
85
80
75
70
65
VOUT = 12V
FSW = 600kHz
CCM
R3 = 23.2k
60
55
18VIN
24VIN
36VIN
48VIN
70VIN
90
EFFICIENCY (%)
24VIN
36VIN
48VIN
85
80
75
70
VOUT = 12V
FSW = 600kHz
R3=23.2kΩ
65
60
0.1
1
3
18VIN
24VIN
2
48VIN
1
70VIN
55
50
50
0.01
LOAD CURRENT (A)
95
90
EFFICIENCY (%)
Thermal Derating
10
0
0.6
1.2
1.8
2.4
3
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
3.6
0
25
40
55
70
85
100
MAX. AMBIENT TEMPERATURE (°C)
IC Power Dissipation vs. Output
Current (MIC28304-2)
9
VOUT = 12V
R3 = 23.2kΩ
FSW = 600kHz
IC POWER DISSIPATION (W)
8
7
70VIN
48VIN
36VIN
24VIN
18VIN
6
5
4
3
2
1
0
0
1
2
3
4
OUTPUT CURRENT (A)
Die Temperature* : The temperature measurement was taken at the hottest point on the MIC28304 case mounted on a 5 square inch 4 layer, 0.62”,
FR-4 PCB with 2oz. finish copper weight per layer. Actual results will depend upon the size of the PCB, ambient temperature and proximity to other heat
emitting components.
April 29, 2014
10
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 12V/3A Output Evaluation Board Schematic
Figure 6. Schematic of MIC28304 Evaluation Board
(J1, J8, J10, J11, J12, J13, R14, R20 and R21 are for testing purposes)
April 29, 2014
11
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 12V/3A Output Evaluation Board Schematic (Continued)
Figure 7. Schematic of MIC28304 Evaluation Board
(Optimized for smallest footprint)
April 29, 2014
12
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
Bill of Materials 12V/3A Output
Item
C1, C1A
Part Number
(9)
EEU-FC2A101
GRM32ER72A225K
C2, C3,
(9)
(9)
C2A , C3A
C6, C6A(9)
12101C225KAT2A
AVX
GCM1885C2A100JA16D
Murata
C10, C17,
C10A(9),
(9)
C17A
C1608X5R0J105K
TDK
C1608X7S2A104K
GRM188R72A102KA01D
C11, C11A
C12, C12A
C14, C14A(9)
C16, C16A
AVX
Murata
4
10pF, 100V, 0603, NPO
2
1µF/6.3V Ceramic Capacitor, X7R, Size 0603
2
0.47µF/100V Ceramic Capacitor, X7R, Size
0805
2
0.1µF/100V,X7S,0603
Murata
TDK
1nF/100V Ceramic Capacitor, X7R, Size 0603
2
2.2nF/100V Ceramic Capacitor, X7R, Size 0603
2
Murata
06031C222KAT2A
AVX
C1608X7R2A222K
TDK
EMK325BJ476MM-T
2.2µF/100V Ceramic Capacitor, X7R, Size 1210
4
C1608X7R2A102K
GRM32ER61C476ME15
2
0.1µF/100V Ceramic Capacitor, X7R, Size 0603
TDK
AVX
GRM188R71H104KA93D
(9)
Murata
06031C102KAT2A
GRM188R72A222KA01D
(9)
100µF Aluminum Capacitor, 100V
Murata
AVX
GRM188R72A104KA35D
(9)
AVX
06036C105KAT2A
08051C474KAT2A
Qty
Murata
(13)
GRM21BR72A474KA73
C9, C9A(9)
Description
(10)
(11)
TDK(12)
GRM188R70J105KA01D
C8, C8A
Panasonic
C3225X7R2A225K
06031A100JAT2A
(9)
Manufacturer
Murata
47µF Ceramic Capacitor, X5R, Size 1210, 16V
(14)
Taiyo Yuden
Murata
06035C104KAT2A
AVX
C1608X7R1H104K
TDK
2
0.1µF/6.3V Ceramic Capacitor, X7R, Size 0603
2
C4, C5, C7,
C13, C15,
C4A(9), C7A(9),
(9)
C15A
DNP
Notes:
9. Either reference designator, that is, a reference designator ending with “A” or ending without “A,” can be used as part of customer design.
10. Panasonic: www.panasonic.com.
11. Murata: www.murata.com.
12. TDK: www.tdk.com.
13. AVX: www.avx.com.
14. Taiyo Yuden: www.taiyo-yuden.com.
April 29, 2014
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Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
Bill of Materials 12V/3A Output (Continued)
Item
Part Number
R1, R1A
(9)
CRCW060310K0FKEA
R2, R2A
(9)
CRCW08051R21FKEA
R3, R3A
(9)
R12, R11A
(9)
(9)
R14, R20, R20A
Manufacturer
Vishay Dale
(15)
Description
Qty
10kΩ Resistor, Size 0603, 1%
2
Vishay Dale
1.21Ω Resistor, Size 0805, 5%
2
CRCW060323K2FKEA
Vishay Dale
23.2kΩ Resistor, Size 0603, 1%
2
CRCW0603715R0FKEA
Vishay Dale
715Ω Resistor, Size 0603, 1%
2
CRCW06030000FKEA
Vishay Dale
0Ω Resistor, Size 0603, 5%
3
R15, R15A
(9)
CRCW04022K70JNED
Vishay Dale
2.7kΩ Resistor, Size 0603, 1%
2
R16, R16A
(9)
CRCW0603100KFKEAHP
Vishay Dale
100kΩ Resistor, Size 0603, 1%
2
R18, R18A
(9)
CRCW060349K9FKEA
Vishay Dale
49.9kΩ Resistor, Size 0603, 1%
2
R21
CRCW060349R9FKEA
Vishay Dale
49.9Ω Resistor, Size 0603, 1%
1
R23, R23A(9))
CRCW06031R21FKEA
Vishay Dale
1.21Ω Resistor, Size 0603, 1%
2
R4, R10, R11,
R19, R19A(9)
U1, U1A(9)
DNP
MIC28304-1YMP
MIC28304-2YMP
Micrel. Inc.(16)
70V, 3A Power Module
2
Notes:
15. Vishay: www.vishay.com.
16. Micrel, Inc.: www.micrel.com.
April 29, 2014
14
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
PCB Layout Recommendations
MIC28304 Evaluation Board Top Layer
MIC28304 Evaluation Board Mid-Layer 1 (Ground Plane)
April 29, 2014
15
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
PCB Layout Recommendations (Continued)
MIC28304 Evaluation Board Mid-Layer 2
MIC28304 Evaluation Board Bottom Layer
April 29, 2014
16
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This
information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry,
specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability
whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical
implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2014 Micrel, Incorporated.
April 29, 2014
17
Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
Revision History
Date
2/15/14
Change Description/Edits by:
Rev.
New Eval Board literature
April 29, 2014
1.0
18
Revision 1.0
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