MIC2103YML-10A Evaluation Board User Guide

MIC2103/04 Evaluation Board
75V, Synchronous Buck Controllers
featuring Adaptive On-Time Control
Hyper Speed Control™ Family
General Description
The Micrel MIC2103/04 are constant-frequency,
synchronous buck controllers featuring a unique
adaptive
on-time
control
architecture.
The
MIC2103/04 operates over an input supply range of
4.5V to 75V and can be used to supply up to 15A of
output current. The output voltage is adjustable down
to 0.8V with a guaranteed accuracy of ±1%. The
device operates with programmable switching
frequency from 200kHz to 600kHz.
The MIC2103 has Hyper Light Load® architecture, so it
can operate in pulse skipping mode at light load.
However, from medium load to heavy load, it operates in
fixed frequency CCM mode. The MIC2104 has Hyper
Speed Control architecture which operates in fixed
frequency CCM mode under all load conditions.
The basic parameters of the evaluation board are:
1. Input: 12V to 75V
2. Output: 0.8V to 5V at 10A (1)
3. 200kHz Switching Frequency (Adjustable 200kHz
to 600kHz)
Note:
1. Refer to temperature curves shown in Typical Characteristics
section.
Datasheets and support documentation can be found
on Micrel’s web site at: www.micrel.com.
Requirements
The MIC2103 and MIC2104 evaluation board requires
only a single power supply with at least 10A current
capability. The MIC2103/04 has internal VDD LDO so
no external linear regulator is required to power the
internal biasing of the IC. In the applications with
VIN < +5.5V, VDD should be tied to VIN to by-pass
the internal linear regulator. The output load can either
be a passive or an active load.
Precautions
The MIC2103/04 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
75V. Exceeding 75V 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 (12V < VIN < 75V). Monitor IIN with a current
meter and input voltage at VIN and GND terminals
with voltmeter. 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 on board 100k pull-up resistor
(R22) to VIN, 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 MIC2103/04 evaluation board.
4. Turn on the Power
Turn on the VIN supply and verify that the output
voltage is regulated to 5.0V.
Ordering Information
Part Number
Description
MIC2103YML 10A EV
MIC2103 Evaluation Board up
to 5V Output
MIC2104YML 10A EV
MIC2104 Evaluation Board up
to 5V 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
October 2012
M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
through the value of the resistor (R17). If the absolute
value of the voltage drop on the bottom FET is greater
than VCL, 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.
Features
Feedback Resistors
The output voltage on the MIC2103/04 evaluation
board, which is preset to 5.0V, is determined by the
feedback divider:

VOUT  VREF   1 



R BOTTOM 
R1
(Eq. 1)
where VREF = 0.8V, and RBOTTOM is one of R4, R5, R6,
R7, R8, R9, R10, R11 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:
RBOTTOM 
R1 VREF
VOUT  VREF
(Eq. 2)
Figure 1. MIC2103/04 Current Limiting Circuit
Note that the output voltage should not be set to
exceed 5V due to the 6.3V voltage rating on the
output capacitors.
The short circuit current limit can be programmed by
using the following formula.
R17 
Current Limit
The MIC2103/04 uses the RDS(ON) and external
resistor connected from ILIM pin to SW node to
decide the current limit.
In each switching cycle of the MIC2103/04 converter,
the inductor current is sensed by monitoring the lowside 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 R17 (VCL) is compared with
the drop over the bottom FET generating the short
current limit. The small capacitor (C18) connected
from ILIM pin to PGND filters the switching node
ringing during the off time to allow a better short limit
measurement. The time constant created by R17 and
C18 should be much less than the minimum off time.
The VCL drop allows programming of short limit
October 2012
( I CLIM   PP  0.5)  R DS (ON )  VCL
(Eq. 3)
I CL
Where ICLIM = Desired Current limit
ΔPP = Inductor current peak to peak
RDS (ON) = On resistance of low-side power MOSFET
VCL = Current limit threshold, the typical value is 14mV
in EC table
ICL = Current Limit source current, the typical value is
80µA in EC table.
In case of a 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 ICL in the above equation to avoid false
current limiting due to increased MOSFET junction
temperature rise. It is also recommended to connect
SW pin directly to the drain of the low-side MOSFET
to accurately sense the MOSFETs RDS(ON).
SW Node
Test point J1 (VSW) is placed for monitoring the
switching waveform, which is one of the most critical
waveforms for the converter.
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M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
Loop Gain Measurement
The 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.
Switching Frequency
700
R19 = 100k, IOUT =10A
600
VIN = 48V
VIN = 12V
500
SW FREQ (kHz)
Setting the Switching Frequency
The
MIC2103/04
are
adjustable-frequency,
synchronous buck controllers featuring a unique
adaptive on-time control architecture. The switching
frequency can be adjusted between 200kHz and
600kHz by changing the resistor divider network
consisting of R19 and R20.
400
VIN =75V
300
200
100
0
10.00
MIC2103/04
VDD
VDD/PVDD
C7
1µF
AGND
BST
100.00
1000.00
10000.00
R20 (k Ohm)
Figure 3. Switching Frequency vs. R20
VIN
VIN
2.2µF
x3
C2, C3, C4
SW
CS
R19
.
FREQ
R20
FB
PGND
Figure 2. Switching Frequency Adjustment
The following formula gives the estimated switching
frequency:
f SW _ ADJ  f O 
R 20
R19  R 20
(Eq. 4)
Where fO = Switching Frequency when R19 is 100k
and R20 being open, fO is typically 600kHz at 12V
input voltage. For more precise setting, it is
recommended to use the following graph:
October 2012
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M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
MIC2103/04 0.8V to 5V/10A Evaluation Board Typical Characteristics
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
EFFICIENCY (%)
80
70
60
50
40
30
100
80
20
1
2
3
4
5
6
7
8
60
50
40
30
1
2
EFFICIENCY (%)
3
4
5
6
7
8
50
40
30
fSW = 200kHz (CCM)
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14
OUTPUT CURRENT (A)
October 2012
fSW = 200kHz (CCM)
0
1
2
3
4
5
6
7 8
9 10 11 12 13 14
Efficiency (VIN = 75V)
vs. Output Current (MIC2103)
100
90
90
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
80
70
60
50
40
30
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
80
70
60
50
40
30
20
fSW = 200kHz (CCM)
10
0
0
30
OUTPUT CURRENT (A)
20
20
10
40
9 10 11 12 13 14
Efficiency (VIN = 48V)
vs. Output Current (MIC2103)
100
EFFICIENCY (%)
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
60
50
OUTPUT CURRENT (A)
90
70
60
0
0
Efficiency (VIN = 38V)
vs. Output Current (MIC2103)
80
70
10
0
9 10 11 12 13 14
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
80
fSW = 200kHz (CCM)
OUTPUT CURRENT (A)
100
90
20
10
0
0
70
Efficiency (VIN = 24V)
vs. Output Current (MIC2103)
100
20
fSW = 200kHz (CCM)
10
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
90
EFFICIENCY (%)
90
EFFICIENCY (%)
100
Efficiency (VIN = 18V)
vs. Output Current (MIC2103)
EFFICIENCY (%)
Efficiency (VIN =12V)
vs. Output Current (MIC2103)
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14
OUTPUT CURRENT (A)
4
fSW = 200kHz (CCM)
10
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14
OUTPUT CURRENT (A)
M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
MIC2103/04 0.8V to 5V/10A Evaluation Board Typical Characteristics (Continued)
100
70
60
90
50
40
30
70
60
40
30
fSW = 200kHz
0
1
2
3
4
5
6
7
8
0
1
2
4
5
6
7
8
0
50
40
30
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
70
60
50
30
5
6
7
8
1
2
3
30
4
5
6
7
8
fSW = 200kHz
0
9 10 11 12 13 14
1
2
VIN = 12V
VOUT = 5.0V
80
`
60
40
V IN = 48V
V OUT = 5.0V
20
fSW = 200kHz
DIE TEMPERATURE (°C)
120
DIE TEMPERATURE (°C)
120
100
3
4
5
6
7
8
Die Temperature* (VIN = 75V)
vs. Output Current
100
80
60
40
VIN = 75V
VOUT = 5.0V
20
fSW = 200kHz
fSW = 200kHz
0
1
2
3
4
5
6
7
8
OUTPUT CURRENT (A)
9
10
0
9 10 11 12 13 14
OUTPUT CURRENT (A)
120
0
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
40
140
20
9 10 11 12 13 14
50
140
40
8
60
140
60
7
0
Die Temperature* (VIN = 48V)
vs. Output Current
Die Temperature* (VIN = 12V)
vs. Output Current
80
6
70
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
100
5
10
fSW = 200kHz
0
9 10 11 12 13 14
4
20
0
0
3
80
40
10
fSW = 200kHz
4
2
Efficiency (VIN = 75V)
vs. Output Current (MIC2104)
100
20
20
3
1
OUTPUT CURRENT (A)
EFFICIENCY (%)
60
EFFICIENCY (%)
70
2
fSW = 200kHz
90
80
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
1
30
9 10 11 12 13 14
90
80
EFFICIENCY (%)
3
Efficiency (VIN = 48V)
vs. Output Current (MIC2104)
100
90
0
40
OUTPUT CURRENT (A)
Efficiency (VIN = 38V)
vs. Output Current (MIC2104)
10
50
0
OUTPUT CURRENT (A)
100
60
10
fsw = 200kHz
0
9 10 11 12 13 14
70
20
10
0
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
80
20
10
DIE TEMPERATURE (°C)
90
50
20
Efficiency (VIN = 24V)
vs. Output Current (MIC2104)
100
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
80
EFFICIENCY (%)
80
EFFICIENCY (%)
100
5.0V
3.3V
2.5V
1.8V
1.2V
0.8V
90
Efficiency (VIN = 18V)
vs. Output Current (MIC2104)
EFFICIENCY (%)
Efficiency (VIN =12V)
vs. Output Current (MIC2104)
0
0
1
2
3
4
5
6
7
8
OUTPUT CURRENT (A)
9
10
0
1
2
3
4
5
6
7
8
9 10
OUTPUT CURRENT (A)
Die Temperature* : The temperature measurement was taken at the hottest point on the MIC2103/04 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.
October 2012
5
M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
MIC2103/04 0.8V to 5V/10A Output Evaluation Board Schematic
Figure 1. MIC2103/04 Evaluation Board for 0.8V to 5V/10A Output
October 2012
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M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
Bill of Materials 0.8V to 5V/10A Output
Item
C1
Part Number
EEU-FC2A101
GRM32ER72A225K
C2, C3, C4
C14
C3225X7R2A225K
AVX
C3225X5ROJ107M
TDK
AVX
C1608X7R1H104K
TDK
AVX
C1608X5R0J105K
TDK
C12
Murata
AVX
Murata
TDK
3
100µF/6.3V Ceramic Capacitor, X5R, Size 1210
1
0.1µF/50V Ceramic Capacitor, X7R, Size 0603
2
1µF/6.3V Ceramic Capacitor, X7R, Size 0603
3
0.47µF/100V Ceramic Capacitor, X7R, Size 0805
1
0.1µF/100V Ceramic Capacitor, X7R, Size 0603
0.1µF/100V,X7S,0603
AVX
C1608X7R2A102K
TDK
1nF/100V Cermiac Capacitor, X7R, Size 0603
1
2.2nF/100V Cermiac Capacitor, X7R, Size 0603
1
Murata
06031C222KAT2A
AVX
C1608X7R2A222K
TDK
Sanyo(5)
470µF/6.3V, 7m-ohms, OSCON
6SEPC470M
Sanyo
470µF/6.3V, 7m-ohms, OSCON
C15 (OPEN)
6TPB470M
Sanyo
470µF/6.3V, POSCAP
C5 (OPEN)
GRM32ER60J107ME20L
Murata
100µF/6.3V Ceramic Capacitor, X7R, Size 1210
GCM1885C2A100JA16D
Murata
C13
C18
D1
6SEPC470MX
06031A100JAT2A
BAT46W-TP
L1
CDEP147NP-6R1MC-95
1
Murata
06031C102KAT2A
GRM188R72A222KA01D
2.2µF/100V Ceramic Capacitor, X7R, Size 1210
Murata
06036C105KAT2A
C1608X7S2A104K
1
Murata
06035C104KAT2A
GRM188R72A104KA35D
Qty
(4)
12106D107MAT2A
GRM188R72A102KA01D
C11
TDK
100µF Aluminum Capacitor, 100V
(3)
Murata
08051C474KAT2A
C10
Murata
GRM32ER60J107ME20L
GRM21BR72A474KA73
C9
(1)
(2)
AVX
GRM188R70J105KA01D
C7, C8, C17
Panasonic
12101C225KAT2A
GRM188R71H104KA93D
C6, C16
Manufacturer Description
10pF, 100V, 0603, NPO
AVX
MCC(6)
Sumida
(7)
1
1
100V Small Signal Schottky Diode, SOD123
1
6.1µH Inductor, 14.8A RMS Current
1
Notes:
1.
Panasonic: www.panasonic.com.
2.
Murata: www.murata.com.
3.
TDK: www.tdk.com.
4.
AVX: www.avx.com
5.
Sanyo: www.sanyo.com.
6.
MCC.: www.mccsemi.com.
7.
Sumida: www.sumida.com.
October 2012
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M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
Bill of Materials 0.8V to 5V/10A Output (Continued)
Item
Part Number
Q1
SIR878DP
Q3
SIR882DP
Manufacturer Description
(8)
Vishay
Qty
MOSFET, N-CH, Power SO-8
1
Vishay
MOSFET, N-CH, Power SO-8
1
Q2, Q4 (OPEN)
R1
CRCW060310K0FKEA
Vishay Dale
10kΩ Resistor, Size 0603, 1%
1
R2, R23
CRCW08051R21FKEA
Vishay Dale
1.21Ω Resistor, Size 0805, 5%
2
R3
CRCW060395K30FKEA
Vishay Dale
95.3kΩ Resistor, Size 0603, 1%
1
R4
CRCW060380K6FKEA
Vishay Dale
80.6kΩ Resistor, Size 0603, 1%
1
R5
CRCW060340K2FKEA
Vishay Dale
40.2kΩ Resistor, Size 0603, 1%
1
R6
CRCW060320K0FKEA
Vishay Dale
20kΩ Resistor, Size 0603, 1%
1
R7
CRCW060311K5FKEA
Vishay Dale
11.5kΩ Resistor, Size 0603, 1%
1
R8
CRCW06038K06FKEA
Vishay Dale
8.06kΩ Resistor, Size 0603, 1%
1
R9
CRCW06034K75FKEA
Vishay Dale
4.75kΩ Resistor, Size 0603, 1%
1
R10
CRCW06033K24FKEA
Vishay Dale
3.24kΩ Resistor, Size 0603, 1%
1
R11
CRCW06031K91FKEA
Vishay Dale
1.91kΩ Resistor, Size 0603, 1%
1
R12 (OPEN)
CRCW0603715R0FKEA
Vishay Dale
715Ω Resistor, Size 0603, 1%
R13 (OPEN)
CRCW0603348R0FKEA
Vishay Dale
348Ω Resistor, Size 0603, 1%
R14, R15
CRCW06030000FKEA
Vishay Dale
0Ω Resistor, Size 0603, 5%
2
R16
CRCW08052R0FKEA
Vishay Dale
2Ω Resistor, Size 0805, 5%
1
R17
CRCW06032K21FKEA
Vishay Dale
2.21kΩ Resistor, Size 0603, 1%
1
R18, R20
CRCW060349K9FKEA
Vishay Dale
49.9kΩ Resistor, Size 0603, 1%
2
R19, R22
CRCW0603100K0FKEA
Vishay Dale
100kΩ Resistor, Size 0603, 1%
2
R21
CRCW060349R9FKEA
Vishay Dale
49.9Ω Resistor, Size 0603, 1%
1
MIC2103YML
U1
MIC2104YML
Micrel. Inc.(9) 75V Synchronous Buck DC-DC Controller
1
Notes:
8.
Vishay: www.vishay.com.
9.
Micrel, Inc.: www.micrel.com.
October 2012
8
M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
Evaluation Board PCB Layout
MIC2103/04 Evaluation Board  Copper Layer 1 (Top)
MIC2103/04 Evaluation Board  Copper Layer 2 (Mid-Layer 1)
October 2012
9
M9999-100512
Micrel, Inc.
MIC2103/04 10A Evaluation Board
Evaluation Board PCB Layout (Continued)
MIC2103/04 Evaluation Board  Copper Layer 3 (Mid-Layer 2)
MIC2103/04 Evaluation Board  Copper Layer 4 (Bottom)
October 2012
10
M9999-100512
Micrel, Inc.
MIC2103/04 10A 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.
October 2012
11
© 2012 Micrel, Incorporated.
M9999-100512