MIC28304 Evaluation Board
70V 3A Power Module
Hyper Speed Control™ Family
General Descr i ption
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.
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 parameter s of t he evaluation board are:
• Input: 7V to 70V
• Output: 0.8V to 5V at 3A (1)
• 600kHz Switching Fr equency (Adjustable 200kHz
to 600kHz)
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.
Getting Started
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.
2. Connect Load and Monitor Outpu t
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 t he 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.
4. Turn Po wer
Turn on the VIN supply and verify that the output
voltage is regulat ed to 5V.
Ordering I nfor m ati on
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 E V MIC28304-1 Evaluation
Board 12V Output
MIC28304-2 12V E V 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
Features
Feedback Resistors
The output voltage on the MIC28304 evaluation board,
which is preset to 5.0V, is determined by the feedback
divider:
+×= BOTTOM
REFOUT RR1
1VV
Eq. 1
where VREF = 0.8V, and RBOTTOM is one o f R10, or R11,
which corresponds to 3.3V, 5V. Leav i ng the RBOTTOM open
gives a 0.8V output vol t age. All other voltages not listed
above can be set by modifying RBOTTOM value according to:
REFOUT
REF
BOTTOM
VV VR1
R−
×
=
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 detai ls refer to Bill of Mat erial t abl e.
Table 1. Typi cal Values of Some Components
VOUT VIN R3
(Rinj) R1
(Top Feedb ack Resistor) R11
(Bottom Feedback Resistor) C10
(Cinj) C12
(Cff) COUT
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 Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
SW Node
Test point J1 (VSW) is placed for monitoring the switching
waveform, which is one of the most critical waveforms for
the converter.
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 cu rrent limit.
SW
FB
2.2µF
x2
MIC28304
BST
PGND
VIN
VIN
SW
CS
ILIM
R15
C6
Figure 1. MIC28304 Current Limiting Circuit
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 tha n t he m ini m um off time.
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 f or sev ere short conditions.
The short circuit current limit can be programmed by using
the following formula:
( )
CL
CL)ON(DS
PP
LCLIM
IVR)5.0II(
R15 +××∆−
=
Eq. 3
ICLIM = Desired 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)
ICL = Current-limit source current (typical value is 80µA,
per the Electrical C haracteristics table).
ΔIL(PP) = Inductor current peak-to-peak, since the inductor
is integrated use Equation 4 to calculate the inductor ripple
current.
The peak-to-peak indu ct or current ripple is:
L f V )V(VV
I
swIN(max)
OUTIN(max)OUT
L(PP)
××
−×
=∆
Eq. 4
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.
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.
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 .
R15 Typical Output Current Limit
1.81kΩ 3A
2.7kΩ 6.3A
April 29, 2014 3 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 resist or value in between 20Ω to 50Ω.
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.
SW
FB
2.2µF
x2
MIC28304
BST
PGND
VIN
VIN
FREQ CS
R19
RFREQ
100kΩ
Figure 2. Switching Frequenc y Adjustment
The following formula gives the estimated switching
frequency:
Ω+
×= k10019R 19R
ff OADJ_SW
Eq. 5
Where fO = Switching Frequency when R19 is open. For a
more precise setting, it is recommended to use the
following graph:
Figure 3. Switching Frequency vs. R19
0
100
200
300
400
500
600
700
800
10.00 100.00 1000.00 10000.00
SW FREQ (kHz)
R19 (kΩ)
Switching Frequency
V
OUT
= 5V
I
OUT
= 2A
VIN = 48V
VIN = 12V
April 29, 2014 4 Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 0.8V to 5V/ 3A Ev al uati on Board Typi cal Characteristics
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.
10
20
30
40
50
60
70
80
90
100
0.01 0.1 110
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency (VIN = 12V)
vs. Output Current (MIC28304-1)
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
F
SW
= 600kHz
CCM
10
20
30
40
50
60
70
80
90
100
0.01 0.1 110
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency (VIN = 18V)
vs. Output Current (MIC28304-1)
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
F
SW
= 600kHz
CCM
10
20
30
40
50
60
70
80
90
100
0.01 0.1 110
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency (VIN = 24V)
vs. Output Current (MIC28304-1)
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
F
SW
= 600kHz
CCM
30
40
50
60
70
80
90
100
00.5 11.5 22.5 33.5 4
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency (VIN =12V)
vs. Output Current (MIC28304-2)
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
FSW = 600kHz
30
40
50
60
70
80
90
100
00.5 11.5 22.5 33.5 4
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency (VIN = 18V)
vs. Output Current (MIC28304-2)
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
FSW = 600kHz
30
40
50
60
70
80
90
100
00.5 11.5 22.5 33.5 4
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency (VIN = 24V)
vs. Output Current (MIC28304-2)
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
FSW = 600kHz
0
1
2
3
25 40 55 70 85 100
LOAD CURRENT (A)
MAXIMUM AMBIENT TEMPERATURE
(°C)
Thermal Derating
V
OUT
= 5V
F
SW
= 600kHz
MIC28304-2
T
j_MAX
= 125°C
VIN = 18V
VIN = 12V
VIN = 24V
VIN = 48V
VIN = 70V
0
1
2
3
25 40 55 70 85 100
LOAD CURRENT (A)
MAXIMUM AMBIENT TEMPERATURE
(°C)
Thermal Derating
VOUT = 3.3V
FSW = 600kHz
MIC28304-2
Tj_MAX = 125°C
VIN = 18V
VIN = 12V
VIN = 24V
VIN = 48V
VIN = 70V
0
1
2
3
25 40 55 70 85 100
LOAD CURRENT (A)
MAXIMUM AMBIENT TEMPERATURE
(°C)
Thermal Derating
V
OUT
= 2.5V
F
SW
= 600kHz
MIC28304-2
T
j_MAX
= 125°C
VIN =18V
VIN = 12V
VIN = 24V
VIN = 48V
VIN = 70V
April 29, 2014 5 Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 0.8V to 5V/3A Output Eval u at ion Bo a r d Sche m ati c
Figure 4. Schematic of MIC28304 Evaluation Board
(J1, J8, J10, J11, J12, J13, R14, R20, and R21 are for testin g 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 Part Number Manufacturer Description Qty
C1, C1A(2) EEU-FC2A101 Panasonic(3) 100µF Aluminum Capacitor, 100V 2
C2, C3, C2A(2),
C3A(2)
GRM32ER72A225K Murata(4)
2.2µF/100V Ceramic Capacitor, X7R, Size 1210 4 C3225X7R2A225K TDK(5)
12101C225KAT2A AVX(6)
C6, C6A(2) GCM1885C2A100JA16D Murata 10pF, 100V, 0603, NPO 2
06031A100JAT2A AVX
C8, C8A(2)
GRM188R70J105KA01D Murata
1µF/6.3V Cera mic Capacitor, X7R, Size 0603 2 06036C105KAT2A AVX
C1608X5R0J105K TDK
C9, C9A(2) GRM21BR72A474KA73 Murata 0.47µF/100V Ceramic Capac i tor, X7R, Size 0805 2
08051C474KAT2A AVX
C10, C17,
C10A(2),
C17A(2)
GRM188R72A104KA35D Murata 0.1µF/ 100V Ceramic C apacitor, X7R, S ize 0603 4
C1608X7S2A104K TDK 0.1µF/100V, X7S, 0603
C11, C11A(2)
GRM188R72A102KA01D Murata
1nF/100V Ceramic Capacitor, X7R, Size 0603 2 06031C102KAT2A AVX
C1608X7R2A102K TDK
C12, C12A(2)
GRM188R72A222KA01D Murata
2.2nF/100V Ceramic Capaci tor, X7R, Size 0603 2 06031C222KAT2A AVX
C1608X7R2A222K TDK
C14, C14A(2) GRM31CR60J476ME19K Murata 47µF/6.3V Ceramic Capacitor, X5R, Size 1210 2
12106D476MAT2A AVX
C16, C16A(2)
GRM188R71H104KA93D Murata
0.1µF/6.3V Ceramic Capacit or, X7R, Size 0 603 2 06035C104KAT2A AVX
C1608X7R1H104K TDK
C4, C5, C7,
C13, C15,
C4A(2), C7A(2),
C15A(2)
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 Qty
R1, R1A(2) CRCW060310K0FKEA Vishay Dale(7) 10kΩ Resist or, Size 0603, 1% 2
R2, R2A(2) CRCW08051R21FKEA Vishay Dale 1.21Ω Resistor, Size 0805, 5% 2
R3, R3A(2) CRCW06031652F Vishay Dale 16.5kΩ Resistor, Size 0603, 1 % 2
R10, CRCW06033K24FKEA Vishay D ale 3.24kΩ Resistor, Size 0603, 1% 1
R11, R11A(2) CRCW06031K91FKEA Vishay Dale 1.91kΩ Resistor, S i z e 0603, 1% 2
R12 CRCW0603715R0FKEA Vishay Dale 715Ω Resistor, Size 0603, 1% DNP
R14, R20, R20A(2) CRCW06030000FKEA V ishay Dale 0Ω Resistor, Si z e 0603, 5% 3
R15, R15A(2) CRCW04022K70JNED Vishay Dale 2.7kΩ Res istor, Size 0603, 1% 2
R16, R16A(2) CRCW0603100KFKEAHP Vis hay Dale 100kΩ Res i s tor, Size 0603, 1% 2
R18, R18A(2) CRCW060349K9FKEA Vishay D al e 49.9kΩ Resistor, Size 0603, 1% 2
R21 CRCW060349R9FKEA Vishay Dale 49.9Ω Resistor, Size 0603, 1% 1
R23, R23A(2) CRCW06031R21FKEA Vishay Dale 1.21Ω Res istor, Siz e 0603, 1% 2
R4, R19, R19A
(2)
DNP
U1, U1A(2) 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/3 A E v aluat i on Bo ar d Ty pical Ch ar act eri stics
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.
50
55
60
65
70
75
80
85
90
95
100
0.01 0.1 110
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency
vs. Output Current (MIC28304-1)
V
OUT
= 12V
F
SW
= 600kHz
CCM
R3 = 23.2k
18VIN
24VIN
36VIN
48VIN
50
55
60
65
70
75
80
85
90
95
100
00.6 1.2 1.8 2.4 33.6
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency
vs. Output Current (MIC28304-2)
V
OUT
= 12V
F
SW
= 600kHz
R3=23.2kΩ
18VIN
24VIN
36VIN
48VIN
70VIN
0
1
2
3
4
25 40 55 70 85 100
LOAD CURRENT (A)
MAX. AMBIENT TEMPERATURE (°C)
Thermal Derating
V
OUT
= 12V
F
SW
=600kHz
MIC28304-2
R3=23.2k
T
j_MAX
=125°C
24VIN
48VIN
18VIN
70VIN
0
1
2
3
4
5
6
7
8
9
0 1 2 3 4
IC POWER DISSIP AT ION (W)
OUTPUT CURRENT (A)
IC Power Dissipation vs. Output
Current (MIC28304-2)
V
OUT
= 12V
R3 = 23.2kΩ
F
SW
= 600kHz 70VIN
48VIN
36VIN
24VIN
18VIN
April 29, 2014 10 Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
MIC28304 12V/3A Output E valuation 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 E valuation 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 Out put
Item Part Number Manufacturer Description Qty
C1, C1A(9) EEU-FC2A101 Panasonic(10) 100µF Alumin um Capacitor, 100V 2
C2, C3,
C2A(9), C3A(9)
GRM32ER72A225K
Murata(11)
2.2µF/100V Ceramic Capacitor, X7R, Size 1210 4 C3225X7R2A225K TDK(12)
12101C225KAT2A
AVX(13)
C6, C6A(9) GCM1885C2A100JA16D Murata 10pF, 100V, 0603, NPO 2
06031A100JAT2A AVX
C8, C8A(9)
GRM188R70J105KA01D
Murata
1µF/6.3V Cera mic Capacitor, X7R, Size 0603 2 06036C105KAT2A AVX
C1608X5R0J105K
TDK
C9, C9A(9) GRM21BR72A474KA73 Murata 0.47µF/100V Ceramic Capac i tor, X7R, Size
0805 2
08051C474KAT2A AVX
C10, C17,
C10A(9),
C17A(9)
GRM188R72A104KA35D Murata
0.1µF/100V Ceramic Capacit or, X7R, Size 0 603
4
C1608X7S2A104K TDK 0.1µF/100V,X7S,0603
C11, C11A(9)
GRM188R72A102KA01D Murata
1nF/100V Ceramic Capacitor, X7R, S i z e 0603 2 06031C102KAT2A AVX
C1608X7R2A102K TDK
C12, C12A(9)
GRM188R72A222KA01D
Murata
2.2nF/100V Ceramic Capacit or, X7R, Size 0 603 2 06031C222KAT2A AVX
C1608X7R2A222K TDK
C14, C14A(9) GRM32ER61C476ME15 Murata
47µF Ceramic Capacitor, X 5R, Size 1210, 1 6V 2
EMK325BJ476MM-T Taiyo Yuden(14)
C16, C16A(9)
GRM188R71H104KA93D
Murata
0.1µF/6.3V Ceramic Capacit or, X7R, Size 0 603
2
06035C104KAT2A AVX
C1608X7R1H104K TDK
C4, C5, C7,
C13, C15,
C4A(9), C7A(9),
C15A(9)
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 13 Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
Bill of Materials 12V/3A Output (Continued)
Item Part Number Manufacturer Description Qty
R1, R1A(9) CRCW060310K0FKEA Vishay Dale(15) 10kΩ Resistor, S i z e 0603, 1% 2
R2, R2A(9)
CRCW08051R21FKEA
Vishay Dale
1.21Ω Resistor, Size 0805, 5%
2
R3, R3A(9) CRCW060323K2FKEA Vishay Dale 23.2kΩ Resistor, Size 0603, 1% 2
R12, R11A(9)
CRCW0603715R0FKEA
Vishay Dale
715Ω Resistor, Size 0603, 1%
2
R14, R20, R20A(9) CRCW06030000FKEA V ishay Dale 0Ω Resist or, Size 0603, 5% 3
R15, R15A(9) CRCW04022K70JNED Vishay Dale 2.7kΩ Res istor, Size 0603, 1% 2
R16, R16A(9)
CRCW0603100KFKEAHP
Vishay Dale
100kΩ Resisto r, Size 0603, 1%
2
R18, R18A(9) CRCW060349K9FKEA Vishay D al e 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, S ize 0603, 1% 2
R4, R10, R11,
R19, R19A(9) DNP
U1, U1A(9) 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 Ev aluati on Board Top Lay er
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
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nd Purchaser agrees to fully
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© 2014 Micrel, Incorporated.
April 29, 2014 17 Revision 1.0
Micrel, Inc.
MIC28304 Evaluation Board
Revision Hi stor y
Date
Change Description/Edits by:
Rev.
2/15/14 New Eval Board literature 1.0
April 29, 2014 18 Revision 1.0
