Page 1
General Description
MIC28510 Evaluation Board
75V/4A Hyper Speed Control™
Synchronous DC/DC Buck Regulator
Getting Started
The MIC28510 DC/DC regulator operate
input supply range of 4.5V to 75V and
regulated output at up to 4A of output cu
output volta
ge is adjustable down to 0.8V with
typical accuracy of ±1%. The switching freq
adjustable and once adju
remains fairly constant with chang
and output
load.
The basic parameters of the eva
sted the switching fre
es in in
luation board are:
s over an
provides a
rrent. The
a
uency is
quency
put voltage
• Input Voltage − 5V to 75V
(1)
Output Voltage − 0.8V to 5V at 4A
•
12V at up to 4A
•
250kHz Switching Frequency
(2)
(Adjustable from 100kHz to 500kHz)
Notes:
1, 2. Refer to thermal de-rating curves shown in Typica
Characteristics section.
l
Datasheets and support documenta found
on Micrel’
s web site at: www.micrel.com
tion can be
Requirements
The MIC28510 evaluation board requires o
power supply with at least 10A current ca
linear regulator, which includes a Zener an
transisto
housekeeping (V
r, has been installed on the board to provide
) for the MIC28510. The output
DD
nly a ngle
si
pab y. A
ilit
d an N
NP
load can either be a passive or an active load.
Precautions
The MIC28510 evaluation board does not have
reverse polarity protection. Applying a negative
voltage to the PVIN and GND terminals may damage
the device. The maximum PVIN of the board is rated
at 75V. Exceeding 75V on the PVIN could damage the
device.
1. VIN Supply. Connect a po
and GND terminals, paying
polarity and supply voltag
75V). The input current IIN
a current meter. Do not app
2. Connect Load and Monito
load to the V
OUT
and
GND terminals. The load can
be either a passive (resisti
an electronic load) type. A
placed between the V
monitor the output current. Ensu
voltage is monitored at the V
3. Enable Input. The EN pin ha
pull-up resis
tor to VDD, which allows the output to
be turned on when VDD exce
threshold. An EN connec
wer supply to the VIN
careful attention to the
e range (5V < VIN <
can be monitored with
ly power until Step 4.
r Output. Connect a
ve) or an active (as in
current meter may be
terminal and load to
OUT
re the output
terminal.
OUT
s an internal 100k
eds its UVLO
tor is provided on the
evaluation board for users to easily access the
enable
feature. Applying an external logic signal
on the E
short the EN pin to GND
N pin to pull it low or using a jumper to
will shut off the output of
tiothe MIC28510 evalua
n board.
4. Turn On the Power. Turn on the VIN supply and
verify that the output voltage is regulated to 3.3V.
Ordering Information
Part Number Description
MIC28510 5V EV Evaluation Board up to 5V Output
MIC28510 12V EV Evaluation Board 12V Output
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
March 2012
M9999-030712
or (408) 955-1690
Page 2
Micrel, Inc. MIC28510 4A Evaluation Board
Features
Feedback Resistors
The output voltage on the
board, which is preset to 3.3V, is determined by the
feedback divider, shown in Equation 1:
REFOUT
where V
which corresponds
= 0.8V, and R
REF
to 0.9V, 1.0V, 1.2V, 1.5V, 1.8V,
2.5V, 3.3V, or 5V. Leaving the R
0.8V output voltage. All
above can be set by modifying R
according to Equation 2:
R
BOTTOM
=
Note that the output voltage should not be
5V due to the 6.3V voltage rating o
output capacitors.
If higher than 5V output is desired, it is reco
to use the designs s
hown in the MIC28510 12V/4A
output evaluation board schematic, where th
capacitors, L1, R3, and R17 are optimize
output.
SW N
ode
Test point J11 (V
) is placed for monitori
SW
switching waveform, one of the mos
waveforms for the converter.
Current Limit
The MIC28510 has internal FETs, and the curre
is implemented by sensing the R
The MIC28510 has a fixed current limi
(typical).
Loop Gain M
easurement
The resistor, R13, is placed in series with the reg
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.
Setting the Switching Frequency
The MIC28510 is an adjustable-frequency,
synchronous buck regulator featuring a unique
digitally modified adaptive on-time control
architecture.
March 2012
MIC28510 evaluation
⎜
⎜
⎝
1VV
+×=
R
BOTTOM
R4
BOTTOM
⎞⎛
⎟
⎟
⎠
is one o
open gives a
BOTTOM
Eq. 1
f R5-R12,
other voltages not listed
alu
v e
Eq. 2
set to
VR4×
−
REF
VV
REFOUT
BOTTOM
n the exceed
mmended
e output
d for 12V
ng the
t critical
nt limit
DS-ON
of bott
om FET.
6.5A
t of
ulator
The switching frequency can
100kHz and 500kHz by changi
connected network consisting of R18 and R19 from
PVIN to PGND.
Figure 1. Switching Frequency Adjustment
Equation 3 illustrates the estimated
ff
×=
OSW_ADJ
where f
and R19 being open, f
For more precise setting, it is recommended to use
Figure 2:
The evaluation board design is optimized for a
switching frequency of 250kHz. If the switching
frequency is programmed to either lower end or higher
end, the design needs optimization.
2
= Switching Frequency when R18 is 100k
O
should be typically 450kHz.
O
Figure 2. Switching Frequency vs. R19
be adjusted between
ng the resistor divider
switching frequency:
R19
Eq. 3
R19R18
+
M9999-030712
or (408) 955-1690
Page 3
Micrel, Inc. MIC28510 4A Evaluation Board
MIC28510 0.8V to 5V/4A Evaluation Board Typical Characteristics
Efficiency ( VIN = 48V)
vs. Output Current
100
90
80
70
60
50
40
EFFICI ENCY ( % )
30
20
10
012345
fSW = 250kHz
OUTPUT CURRENT (A)
5.0V
3.3V
2.5V
1.8V
1.5V
1.2V
1.0V
0.9V
0.8V
6
The rmal De rating
4
3
2
VIN= 75V
VIN = 48V
1
LOAD CURRENT (A)
VIN= 5V
0
25 40 55 70 85 100
MAXIMUM AMBI ENT TEM PERATURE
(°C)
V
= 3.3V
OUT
fsw = 250k Hz
L = 10µH
=125°C
T
j_MAX
4
3
2
1
LOAD CURRENT (A)
0
25 40 55 70 85 100
Thermal Deratin g
VIN = 8V
VIN= 48V
V
= 75V
IN
V
= 5V
OUT
f
= 250kHz
SW
L = 10µH
= 125°C
T
j_MAX
MAXIMUM AMBIENT TEMPERATURE
(°C)
Therma l De rat ing
4
V
= 5V
OUT
f
= 250kHz
SW
L = 10µH
3
= 125°C
T
j_MAX
2
OAD CURRENT ( A)
1
L
VIN = 24V
VIN =18V
4
3
2
1
LOAD CURRENT ( A)
The rmal De rat ing
V
= 3.3V
OUT
f
= 250kHz
SW
L = 10µH
T
= 125°C
j_MAX
VIN = 12V
VIN =18V
VIN = 24V
4
3
2
1
LOAD CURRENT ( A)
Therma l Derating
V
= 2.5V
OUT
f
= 250kHz
SW
L = 10µH
T
= 125°C
j_MAX
VIN= 12V
VIN=18V
VIN= 24V
V
= 12V
0
25 40 55 70 85 100
MAXIMUM AMBIENT TEMPERATURE
IN
(°C)
0
25 40 55 70 85 100
MAXIMUM AM BI ENT TEM PERATURE
(°C)
0
25 40 55 70 85 100
MAXIMUM AMBIENT TEMPERATURE
(°C)
Die Temperature* : The temperature measurement was taken at the hottest point on the MIC28510 case mounted on a 5 square inch 4 layer, 0.62”,
FR-4 PCB with 2oz. finish copper weight per layer, see Thermal Measurement section. Actual results will depend upon the size of the PCB, ambient
temperature and proximity to other heat emitting components.
March 2012
3
M9999-030712
or (408) 955-1690
Page 4
Micrel, Inc. MIC28510 4A Evaluation Board
MIC28510 0.8V to 5V/4A Output Evaluation Board Schematic
MIC28510 Evaluation Board for 0.8V to 5V/4A Output
March 2012
4
M9999-030712
or (408) 955-1690
Page 5
Micrel, Inc. MIC28510 4A Evaluation Board
ll of 0.8V to u
Bi Materials 5V/4A O tput
Item Manufacturer Description Qty.
C1 EEU-FC2A101B Pa or, SMD, 100V 1 nasonic
C2, C3
C13
C6
C10
C8, C9
C11
C12
C16
C4, C5, C
14, C15
C
D1
D2
L1 DR125-100-R Cooper Bussmann
Q1 FCX493 Diodes Inc/ZETEX
R1 CRCW06034R75FKEA Vishay Dale
R2, R16 CRCW08051R21FKEA Vishay Dale
R3 CRCW060316K5FKEA Vishay Dale
R4 CRCW060310K0FKEA Vishay Dale
R5 CRCW060380K6FKEA Vishay Dale
R6 CRCW060340K2FKEA Vishay Dale
Part Number
(1)
100µF Aluminum Capacit
GRM32ER72A225KA M35L urata
C3225X7R2A2
25KT5 TDK
GRM32ER60J107ME M20L urata
12106D107
MAT2A AVX
06035C104KAT2A AVX
GRM188R71H104KA93D Murata
C1608X7R1H10 TDK
4K
GRM188R72A104KA35D Murata
C1608X7S2A104
K TDK
0805ZC225MAT2A AVX
GRM21BR71A225KA Murata
C2012X7R TDK
1A225K
GRM188R72A102KA01D Murata
C1608X7R2A102K TDK
06031C102K
AT2A AVX
GRM188R71H472KA01D Murata
C1608X7R2A472K TDK
06035C472K
AT2A AVX
GRM21BR71A105K MA01L urata
C2012X K TDK
7,
Open
7R1A105
BAT46W-TP MCC
BAT46W-7-F D des Inc.
io
MMXZ5232B-TP MCC
CMDZ5L6 C tral Semi
en
(2)
(3)
(2)
(4)
(4)
(2)
(3)
(2)
(3)
(4)
(2)
(3)
(2)
(3)
(4)
(2)
(3)
(4)
(2)
(3)
(5)
(5)
2.2µF Ceramic Capacitor,
100µF Ceramic Capacitor, X5R, Size 12
0.1µF Ceramic Capacitor, X7R, Size 0603, 50V 1
0.1µF Ceramic Capacitor, X7R, Size 0603, 100V 1
2.2µF Ceramic Capacitor, X7R, Size 0805, 10V 2
01L
1nF Ceramic Capacitor
4.7nF Ce
1µF Ceramic Capacitor, X7
Small Signal
(6)
5.6V Zener D
(7)
(8)
10µH Inductor, 5.35A RMS, 7A Saturation Current 1
(6)
100V NPN Transistor 1
(9)
4.75Ω Resistor, Size 0603, 1% 1
(9)
1.21Ω Resistor, Size 0805, 1% 2
(9)
16.5kΩ Resistor, Size 0603, 1% 1
(9)
10kΩ Resistor, Size 0603, 1% 1
(9)
80.6kΩ Resistor, Size 0603, 1% 1
(9)
40.2kΩ Resistor, Size 0603, 1% 1
ramic Capacitor, X7R, Size 0603, 50V 1
Schottky Diode 1
iode
X7R, Size 1210, 100V 2
10, 6.3V 1
, X7R, Size 0603, 100V 1
R, Size 0805, 10V 1
1
March 2012
5
M9999-030712
or (408) 955-1690
Page 6
Micrel, Inc. MIC28510 4A Evaluation Board
ll of Mat 8V Output (Co )
Bi erials 0. to 5V/4A ntinued
em mb Description Qty.
It Part Nu er Manufacturer
R7 0F r, Size 0603, 1% 1 CRCW060320K KEA Vishay Dale
R8 5F 3, 1% 1 CRCW060311K KEA Vishay Dale
R9 06F 3, 1% 1 CRCW06038K KEA Vishay Dale
R10 F 3, 1% 1 CRCW06034K75 KEA Vishay Dale 4.75kΩ
R11 24F istor, Size 0603, 1% 1 CRCW06033K KEA Vishay Dale
R12 91F stor, Size 0603, 1% 1 CRCW06031K KEA Vishay Dale
R13 CRCW06030000Z , Size 0603 1 0EAHP Vishay Dale
R14 CRCW080510K0J 5, 1% 1 NEA Vishay Dale 10kΩ Res
R15 CRCW060349R9 , Size 0603, 1% 1 FKEA Vishay Dale 49.9Ω Resistor
R17 (OP 603715R 1% EN) CRCW0 FKEA Vishay Dale
R18, R19 CRCW0603100KFKEAHP Vishay Dale
R20 CRCW06032R00FKEA Vishay Dale
R21 (OPEN) CRCW0603348RFKEA Vishay Dale
U1 MIC28510YJL Micrel. Inc.
Notes:
1. Panasonic: www.panasonic.com.
2. Murata: www.murata.com
3. TDK: www.tdk.com
4. AVX: www.avx.com
5. MCC: www.mccsemi.com
6. Diode Inc.: www.diodes.com
7. Central Semi: www.centralsemi.com
8. Cooper: www.cooperbussman.com
9. Vishay: www.vishay.com
10. Micrel, Inc.: www.micrel.com.
.
.
.
.
.
.
.
.
(9)
20kΩ Resisto
(9)
11.5kΩ Resistor, Size 060
(9)
8.06kΩ Resistor, Size 060
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(9)
(10)
Resistor, Size 060
3.24kΩ Res
1.91kΩ Resi
0Ω Resistor
istor, Size 080
715Ω Resistor, Size 0603,
100kΩ Resistor, Size 0603, 1% 2
2Ω Resistor, Size 0603, 1% 1
348Ω Resistor, Size 0603, 1%
75V/4A Synchronous Buck DC/DC Regulator 1
March 2012
6
M9999-030712
or (408) 955-1690
Page 7
Micrel, Inc. MIC28510 4A Evaluation Board
MIC28510 12V/4A Output Evaluation Board Typical Characteristics
Efficiency
100
95
90
85
80
75
70
65
EFFICIENCY (%)
60
55
50
vs. Output Current
18V
24V
30V
48V
75V
V
= 12V
OUT
f
= 250kHz
SW
L = 27μH
0123456
OUTPUT CURRENT (A)
4
3
2
Load Current (A)
1
0
The rmal Derating
V
= 12V
OUT
=250kHz
f
SW
48V
L=27μH
T
=125°C
j_MAX
18V
IN
IN
24V
IN
75V
IN
25 40 55 70 85 100 115
Maximum Ambient Temperature (°C)
Die Temperature* : The temperature measurement was taken at the hottest point on the MIC28510 case mounted on a 5 square inch 4 layer, 0.62”,
FR-4 PCB with 2oz. finish copper weight per layer, see Thermal Measurement section. Actual results will depend upon the size of the PCB, ambient
temperature and proximity to other heat emitting components.
March 2012
7
M9999-030712
or (408) 955-1690
Page 8
Micrel, Inc. MIC28510 4A Evaluation Board
MIC28510 12V/4A Output Evaluation Board Schematic
MIC28510 Evaluation Board for 12V/4A Output
March 2012
8
M9999-030712
or (408) 955-1690
Page 9
Micrel, Inc. MIC28510 4A Evaluation Board
ll of (12V Up
Bi Materials to 4A) Output
Item Part Number Manufacturer Description
C1 EEU-FC2A101B a or, SMD, 100V 1 P nasonic
C2, C3
C13, C4
GRM32ER61C476ME15 M
EMK325BJ4 T Ta
76MM- iyo Yuden
GRM32ER61C476ME15 Murata
EMK325BJ
476MM-T Taiyo Yuden
06035C104KAT2A AVX
C6
GRM188R71H104KA93D Murata
C1608X7R1H104K T
C10
GRM188R72A104KA35D Murata
C1608X7S2A104
K TDK
0805ZC225MAT2A AVX
C8, C9
GRM21BR71A225KA01L Murata
C2012X7R1A22 TDK
5K
GRM188R72A102KA01D Murata
C11
C1608X7R2A102K
TDK
06031C102KAT2A AVX
GRM188R71H472KA01D Murata
C12
C1608X7R2A472K
TDK
06035C472KAT2A AVX
C16
C5, C7, C
15
C
D1
D2
GRM21BR71A105KA M01L urata
X7R1A105K
C2012 TDK
14,
en
Op
BAT46W-TP MCC
BAT46W-7-F D des Inc.
MMXZ5232B-TP MCC
CMDZ5L6 Cen
io
tral Semi
L1 7447709270 Wurth
Q1 FCX493 Diodes Inc./ZETEX
R1 CRCW06034R75FKEA Vishay Dale
R2, R16 CRCW08051R21FKEA Vishay Dale
R3 CRCW060345K3FKEA Vishay Dale
R4 CRCW060310K0FKEA Vishay Dale
R5 (OPEN) CRCW060380K6FKEA Vishay Dale
R6 (OPEN) CRCW060340K2FKEA Vishay Dale
(1)
100µF Aluminum Capacit
(2)
urata
(2)
(4)
(2)
(5)
DK
(2)
(5)
(4)
(2)
(5)
(2)
(5)
(4)
(2)
(5)
(4)
(2)
(5)
2.2µF Ceramic Capacitor, X7
(3)
47µF Ceramic Capacitor
(3)
0.1µF Ceramic Capacitor, X7
0.1µF Ceramic Capacitor, X7R, Size 0603, 100V 1
2.2µF Ceramic Capacitor, X7R, Size 0805, 10V 2
1nF Ceramic Capacitor, X7
4.7nF Ceramic
1µF Ceramic Capacitor, X7R, Size 0805, 10V 1
Capacitor, X7R, Size 0603, 50V 1
(6)
(6)
(9)
27µH Inductor, 5.8A Saturation Current 1
Small Signal
(7)
5.6V Zener D
(8)
(7)
100V NPN Transistor 1
(10)
4.75Ω Resistor, Size 0603, 1% 1
(10)
1.21Ω Resistor, Size 0805, 1% 2
(10)
45.3kΩ Resistor, Size 0603, 1% 1
(10)
10kΩ Resistor, Size 0603, 1% 1
(10)
80.6kΩ Resistor, Size 0603, 1%
(10)
40.2kΩ Resistor, Size 0603, 1%
Schottky Diode 1
iode
Qty.
R, Size 1210, 100V 2
, X5R, Size 1210, 16V 2
R, Size 0603, 50V 1
R, Size 0603, 100V 1
1
March 2012
9
M9999-030712
or (408) 955-1690
Page 10
Micrel, Inc. MIC28510 4A Evaluation Board
B f Mat V up utput (Conti
ill o erials 12 -to 4A O nued)
Item Part Nu r M nufacturer
R7 (OPEN) CRCW060320K0FK sh or, Size 0603, 1% 1 EA Vi ay Dale
R8 (OPEN) CRCW060311K5FK sh stor, Size 0603, 1% 1 EA Vi ay Dale
R9 (OPEN) CRCW06038K06FK sh stor, Size 0603, 1% 1 EA Vi ay Dale
R10 (OPEN) CRCW06034K75FK sh istor, Size 0603, 1% 1 EA Vi ay Dale 4.75k
R11 (OP 24FK sh sistor, Size 0603, 1% 1 EN) CRCW06033K EA Vi ay Dale
R12 (OP 91FK sh istor, Size 0603, 1% 1 EN) CRCW06031K EA Vi ay Dale
R13 00Z0 sh r, Size 0603 1 CRCW060300 EAHP Vi ay Dale
R14 CRCW080510K0JN sh 5, 1% 1 EA Vi ay Dale 10kΩ Re
R15 CRCW060349R9FKEA sh stor, Size 0603, 1% 1 Vi ay Dale 49.9Ω Resi
R17 603715RFK sh 1 CRCW0 EA Vi ay Dale
R18, R19 CRCW0603100KFKEAHP Vishay Dale
R20 CRCW06032R00FKEA Vishay Dale
R21 (OPEN) CRCW0603348RFKEA Vishay Dale
U1 MIC28510YJL Micrel. Inc.
Notes:
1. Panasonic: www.panasonic.com.
2. Murata: www.murata.com
3. Taiyo Yuden: www.taiyo-yuden.com
4. AVX: www.avx.com
5. TDK: www.tdk.com
6. MCC: www.mccsemi.com
7. Diode Inc.: www.diodes.com
8. Central Semi: www.centralsemi.com
9. Wurth: www.wurth.com
10. Vishay Dale: www.vishay.com
11. Micrel, Inc.: www.micrel.com.
.
.
mbe a Description Qty.
(10)
20kΩ Resist
(10)
11.5kΩ Resi
(10)
8.06kΩ Resi
(10)
(10)
3.24kΩ Re
(10)
1.91kΩ Res
(10)
0Ω Resisto
(10)
(10)
(10)
715Ω Resistor, Size 0603, 1%
(10)
100kΩ Resistor, Size 0603, 1% 2
(10)
2Ω Resistor, Size 0603, 1% 1
(10)
348Ω Resistor, Size 0603, 1%
(10)
75V/4A Synchronous Buck DC/DC Regulator 1
.
.
.
.
.
.
.
Ω Res
sistor, Size 080
March 2012
10
M9999-030712
or (408) 955-1690
Page 11
Micrel, Inc. MIC28510 4A Evaluation Board
Evaluation Board PCB Layout
MIC28510 Evaluation Board − Silkscreen Top
March 2012
MIC28510 Evaluation Board − Copper Layer 1 (Top)
11
M9999-030712
or (408) 955-1690
Page 12
Micrel, Inc. MIC28510 4A Evaluation Board
Evaluation Board PCB Layout (Continued)
MIC28510 Evaluation Board − Copper Layer 2
March 2012
MIC28510 Evaluation Board − Copper Layer 3
12
M9999-030712
or (408) 955-1690
Page 13
Micrel, Inc. MIC28510 4A Evaluation Board
Evaluation Board PCB Layout (Continued)
MIC28510 Evaluation Board − Copper Layer 4
March 2012
MIC28510 Evaluation Board − Silkscreen Bottom
13
M9999-030712
or (408) 955-1690
Page 14
Micrel, Inc. MIC28510 4A Evaluation Board
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB ://www.micrel.comhttp
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.
© 2012 Micrel, Incorporated.
March 2012
14
M9999-030712
or (408) 955-1690
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