MIC28510 Evaluation Board

MIC28510 Evaluation Board
75V/4A Hyper Speed Control™
Synchronous DC/DC Buck Regulator
General Description
Getting Started
The MIC28510 DC/DC regulator operates over an
input supply range of 4.5V to 75V and provides a
regulated output at up to 4A of output current. The
output voltage is adjustable down to 0.8V with a
typical accuracy of ±1%. The switching frequency is
adjustable and once adjusted the switching frequency
remains fairly constant with changes in input voltage
and output load.
The basic parameters of the evaluation board are:
1. VIN Supply. Connect a power supply to the VIN
and GND terminals, paying careful attention to the
polarity and supply voltage range (5V < VIN <
75V). The input current IIN can be monitored with
a current meter. Do not apply power until Step 4.
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 internal 100k
pull-up resistor to VDD, which allows the output to
be turned on when VDD 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 MIC28510 evaluation board.
4. Turn On the Power. Turn on the VIN supply and
verify that the output voltage is regulated to 3.3V.
•
Input Voltage − 5V to 75V
•
Output Voltage − 0.8V to 5V at 4A(1)
(2)
12V at up to 4A
•
250kHz Switching Frequency
(Adjustable from 100kHz to 500kHz)
Notes:
1, 2. Refer to thermal de-rating curves shown in Typical
Characteristics section.
Datasheets and support documentation can be found
on Micrel’s web site at: www.micrel.com
Requirements
The MIC28510 evaluation board requires only a single
power supply with at least 10A current capability. A
linear regulator, which includes a Zener and an NPN
transistor, has been installed on the board to provide
housekeeping (VDD) for the MIC28510. The output
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.
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
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
The switching frequency can be adjusted between
100kHz and 500kHz by changing the resistor divider
connected network consisting of R18 and R19 from
PVIN to PGND.
Features
Feedback Resistors
The output voltage on the MIC28510 evaluation
board, which is preset to 3.3V, is determined by the
feedback divider, shown in Equation 1:
⎛
R4
VOUT = VREF × ⎜⎜1+
⎝ R BOTTOM
⎞
⎟
⎟
⎠
Eq. 1
where VREF = 0.8V, and RBOTTOM is one of R5-R12,
which corresponds to 0.9V, 1.0V, 1.2V, 1.5V, 1.8V,
2.5V, 3.3V, or 5V. Leaving the RBOTTOM open gives a
0.8V output voltage. All other voltages not listed
above can be set by modifying RBOTTOM value
according to Equation 2:
R BOTTOM =
R4 × VREF
VOUT − VREF
Eq. 2
Figure 1. Switching Frequency Adjustment
Equation 3 illustrates the estimated switching frequency:
Note that the output voltage should not be set to
exceed 5V due to the 6.3V voltage rating on the
output capacitors.
If higher than 5V output is desired, it is recommended
to use the designs shown in the MIC28510 12V/4A
output evaluation board schematic, where the output
capacitors, L1, R3, and R17 are optimized for 12V
output.
SW Node
Test point J11 (VSW) is placed for monitoring the
switching waveform, one of the most critical
waveforms for the converter.
Current Limit
The MIC28510 has internal FETs, and the current limit
is implemented by sensing the RDS-ON of bottom FET.
The MIC28510 has a fixed current limit of 6.5A
(typical).
Loop Gain Measurement
The resistor, R13, 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.
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
f SW_ADJ = f O ×
R19
R18 + R19
Eq. 3
where fO = Switching Frequency when R18 is 100k
and R19 being open, fO should be typically 450kHz.
For more precise setting, it is recommended to use
Figure 2:
Figure 2. Switching Frequency vs. R19
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
M9999-030712
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
MIC28510 0.8V to 5V/4A Evaluation Board Typical Characteristics
Thermal Derating
Efficiency (VIN = 48V)
vs. Output Current
4
100
VOUT = 3.3V
fsw = 250kHz
L = 10µH
Tj_MAX =125°C
5.0V
3.3V
2.5V
1.8V
1.5V
1.2V
1.0V
0.9V
0.8V
70
60
50
40
fSW = 250kHz
30
3
VIN = 8V
LOAD CURRENT (A)
EFFICIENCY (%)
LOAD CURRENT (A)
90
80
Thermal Derating
4
2
VIN = 75V
VIN = 48V
1
0
1
2
3
4
5
25
6
VIN = 75V
VOUT = 5V
1
fSW = 250kHz
L = 10µH
Tj_MAX = 125°C
40
55
70
85
25
100
MAXIMUM AMBIENT TEMPERATURE
(°C)
OUTPUT CURRENT (A)
VIN = 24V
VIN = 12V
40
55
70
3
VIN = 12V
VIN =18V
2
VIN = 24V
1
0
0
85
MAXIMUM AMBIENT TEMPERATURE
(°C)
100
85
100
V OUT = 2.5V
LOAD CURRENT (A)
fSW = 250kHz
L = 10µH
Tj_MAX = 125°C
LOAD CURRENT (A)
VOUT = 3.3V
fSW = 250kHz
L = 10µH
Tj_MAX = 125°C
2
70
4
VOUT = 5V
VIN =18V
55
Thermal Derating
4
1
40
MAXIMUM AMBIENT TEMPERATURE
(°C)
Thermal Derating
Thermal Derating
4
LOAD CURRENT (A)
2
0
0
10
25
VIN = 48V
V IN = 5V
20
3
3
fSW = 250kHz
L = 10µH
Tj_MAX = 125°C
3
VIN = 12V
2
VIN =18V
1
VIN = 24V
0
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 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
[email protected] or (408) 955-1690
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
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
Bill of Materials 0.8V to 5V/4A Output
Item
C1
C2, C3
C13
C6
C10
C8, C9
C11
C12
C16
C4, C5, C7,
C14, C15
D1
D2
L1
Q1
R1
R2, R16
R3
R4
R5
R6
March 2012
Part Number
EEU-FC2A101B
GRM32ER72A225KA35L
C3225X7R2A225KT5
GRM32ER60J107ME20L
12106D107MAT2A
06035C104KAT2A
GRM188R71H104KA93D
C1608X7R1H104K
GRM188R72A104KA35D
C1608X7S2A104K
0805ZC225MAT2A
GRM21BR71A225KA01L
C2012X7R1A225K
GRM188R72A102KA01D
C1608X7R2A102K
06031C102KAT2A
GRM188R71H472KA01D
C1608X7R2A472K
06035C472KAT2A
GRM21BR71A105KA01L
C2012X7R1A105K
Manufacturer
Panasonic (1)
Murata(2)
(3)
TDK
Murata(2)
(4)
AVX
AVX(4)
Murata(2)
(3)
TDK
Murata(2)
(3)
TDK
(4)
AVX
Murata(2)
TDK(3)
Murata(2)
TDK(3)
(4)
AVX
Murata(2)
TDK(3)
(4)
AVX
Murata(2)
(3)
TDK
Description
100µF Aluminum Capacitor, SMD, 100V
Qty.
1
2.2µF Ceramic Capacitor, X7R, Size 1210, 100V
2
100µF Ceramic Capacitor, X5R, Size 1210, 6.3V
1
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
1nF Ceramic Capacitor, X7R, Size 0603, 100V
1
4.7nF Ceramic Capacitor, X7R, Size 0603, 50V
1
1µF Ceramic Capacitor, X7R, Size 0805, 10V
1
Small Signal Schottky Diode
1
Open
BAT46W-TP
BAT46W-7-F
MMXZ5232B-TP
CMDZ5L6
DR125-100-R
FCX493
CRCW06034R75FKEA
CRCW08051R21FKEA
CRCW060316K5FKEA
CRCW060310K0FKEA
CRCW060380K6FKEA
CRCW060340K2FKEA
MCC(5)
Diodes Inc.(6)
MCC(5)
Central Semi(7)
Cooper Bussmann(8)
Diodes Inc/ZETEX(6)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
1
5.6V Zener Diode
10µH Inductor, 5.35A RMS, 7A Saturation Current
100V NPN Transistor
4.75Ω Resistor, Size 0603, 1%
1.21Ω Resistor, Size 0805, 1%
16.5kΩ Resistor, Size 0603, 1%
10kΩ Resistor, Size 0603, 1%
80.6kΩ Resistor, Size 0603, 1%
40.2kΩ Resistor, Size 0603, 1%
5
1
1
1
2
1
1
1
1
M9999-030712
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
Bill of Materials 0.8V to 5V/4A Output (Continued)
Item
R7
R8
R9
R10
R11
R12
R13
R14
R15
R17 (OPEN)
R18, R19
R20
R21 (OPEN)
U1
Part Number
CRCW060320K0FKEA
CRCW060311K5FKEA
CRCW06038K06FKEA
CRCW06034K75FKEA
CRCW06033K24FKEA
CRCW06031K91FKEA
CRCW06030000Z0EAHP
CRCW080510K0JNEA
CRCW060349R9FKEA
CRCW0603715RFKEA
CRCW0603100KFKEAHP
CRCW06032R00FKEA
CRCW0603348RFKEA
MIC28510YJL
Manufacturer
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
Vishay Dale(9)
(10)
Micrel. Inc.
Description
20kΩ Resistor, Size 0603, 1%
11.5kΩ Resistor, Size 0603, 1%
8.06kΩ Resistor, Size 0603, 1%
4.75kΩ Resistor, Size 0603, 1%
3.24kΩ Resistor, Size 0603, 1%
1.91kΩ Resistor, Size 0603, 1%
0Ω Resistor, Size 0603
10kΩ Resistor, Size 0805, 1%
49.9Ω Resistor, Size 0603, 1%
715Ω Resistor, Size 0603, 1%
100kΩ Resistor, Size 0603, 1%
2Ω Resistor, Size 0603, 1%
348Ω Resistor, Size 0603, 1%
75V/4A Synchronous Buck DC/DC Regulator
Qty.
1
1
1
1
1
1
1
1
1
2
1
1
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.
March 2012
6
M9999-030712
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
MIC28510 12V/4A Output Evaluation Board Typical Characteristics
Efficiency
vs. Output Current
Thermal Derating
100
4
95
85
80
3
Load Current (A)
90
EFFICIENCY (%)
VOUT = 12V
18V
24V
30V
48V
75V
75
70
VOUT = 12V
65
fSW = 250kHz
L = 27μH
60
fSW =250kHz
L=27μH
Tj_MAX =125°C
24VIN
2
18VIN
48VIN
1
75VIN
55
0
50
0
1
2
3
4
OUTPUT CURRENT (A)
5
6
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
[email protected] or (408) 955-1690
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
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
Bill of Materials (12V Up to 4A) Output
Item
C1
C2, C3
C13, C4
Part Number
EEU-FC2A101B
GRM32ER61C476ME15
EMK325BJ476MM-T
GRM32ER61C476ME15
EMK325BJ476MM-T
06035C104KAT2A
C6
GRM188R71H104KA93D
C1608X7R1H104K
C10
C8, C9
GRM188R72A104KA35D
(3)
Taiyo Yuden
Murata(2)
(3)
Taiyo Yuden
Murata(2)
TDK
Murata(2)
(5)
Murata(2)
1
2.2µF Ceramic Capacitor, X7R, Size 1210, 100V
2
47µF Ceramic Capacitor, X5R, Size 1210, 16V
2
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
TDK
1nF Ceramic Capacitor, X7R, Size 0603, 100V
1
4.7nF Ceramic Capacitor, X7R, Size 0603, 50V
1
1µF Ceramic Capacitor, X7R, Size 0805, 10V
1
Small Signal Schottky Diode
1
(5)
Murata(2)
TDK(5)
06031C102KAT2A
(4)
AVX
Murata(2)
C1608X7R2A472K
TDK(5)
06035C472KAT2A
(4)
C2012X7R1A105K
100µF Aluminum Capacitor, SMD, 100V
(5)
C1608X7R2A102K
GRM21BR71A105KA01L
Qty.
AVX(4)
AVX(4)
GRM188R71H472KA01D
C16
Murata
0805ZC225MAT2A
GRM21BR71A225KA01L
Description
(1)
(2)
TDK
GRM188R72A102KA01D
C12
Panasonic
C1608X7S2A104K
C2012X7R1A225K
C11
Manufacturer
AVX
Murata(2)
TDK(5)
C5, C7, C14,
Open
C15
D1
D2
L1
Q1
R1
R2, R16
R3
R4
R5 (OPEN)
R6 (OPEN)
March 2012
BAT46W-TP
MCC(6)
BAT46W-7-F
Diodes Inc.(7)
MMXZ5232B-TP
CMDZ5L6
7447709270
FCX493
CRCW06034R75FKEA
CRCW08051R21FKEA
CRCW060345K3FKEA
CRCW060310K0FKEA
CRCW060380K6FKEA
CRCW060340K2FKEA
MCC(6)
Central Semi
1
5.6V Zener Diode
(8)
Wurth (9)
(7)
Diodes Inc./ZETEX
27µH Inductor, 5.8A Saturation Current
1
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%
Vishay Dale
Vishay Dale
Vishay Dale
Vishay Dale
Vishay Dale
Vishay Dale
9
M9999-030712
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
Bill of Materials 12V up-to 4A Output (Continued)
Item
R7 (OPEN)
R8 (OPEN)
R9 (OPEN)
R10 (OPEN)
R11 (OPEN)
R12 (OPEN)
R13
R14
R15
R17
R18, R19
R20
R21 (OPEN)
U1
Part Number
CRCW060320K0FKEA
CRCW060311K5FKEA
CRCW06038K06FKEA
CRCW06034K75FKEA
CRCW06033K24FKEA
CRCW06031K91FKEA
CRCW06030000Z0EAHP
CRCW080510K0JNEA
CRCW060349R9FKEA
CRCW0603715RFKEA
CRCW0603100KFKEAHP
CRCW06032R00FKEA
CRCW0603348RFKEA
MIC28510YJL
Manufacturer
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
Vishay Dale(10)
(10)
Micrel. Inc.
Description
20kΩ Resistor, Size 0603, 1%
11.5kΩ Resistor, Size 0603, 1%
8.06kΩ Resistor, Size 0603, 1%
4.75kΩ Resistor, Size 0603, 1%
3.24kΩ Resistor, Size 0603, 1%
1.91kΩ Resistor, Size 0603, 1%
0Ω Resistor, Size 0603
10kΩ Resistor, Size 0805, 1%
49.9Ω Resistor, Size 0603, 1%
715Ω Resistor, Size 0603, 1%
100kΩ Resistor, Size 0603, 1%
2Ω Resistor, Size 0603, 1%
348Ω Resistor, Size 0603, 1%
75V/4A Synchronous Buck DC/DC Regulator
Qty.
1
1
1
1
1
1
1
1
1
1
2
1
1
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.
March 2012
10
M9999-030712
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
Evaluation Board PCB Layout
MIC28510 Evaluation Board − Silkscreen Top
MIC28510 Evaluation Board − Copper Layer 1 (Top)
March 2012
11
M9999-030712
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
Evaluation Board PCB Layout (Continued)
MIC28510 Evaluation Board − Copper Layer 2
MIC28510 Evaluation Board − Copper Layer 3
March 2012
12
M9999-030712
[email protected] or (408) 955-1690
Micrel, Inc.
MIC28510 4A Evaluation Board
Evaluation Board PCB Layout (Continued)
MIC28510 Evaluation Board − Copper Layer 4
MIC28510 Evaluation Board − Silkscreen Bottom
March 2012
13
M9999-030712
[email protected] or (408) 955-1690
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 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.
© 2012 Micrel, Incorporated.
March 2012
14
M9999-030712
[email protected] or (408) 955-1690