MIC4950
Hyper Speed Control™ 5A Buck Regulator
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 20, 2014
Revision 1.1
General Description
The MIC4950 is a high-efficiency, 5A synchronous buck
regulator with ultra-fast transient response. It is perfectly
suited for supplying processor core and I/O voltages from
a 5V or 3.3V bus. The MIC4950 provides a switching
frequency up to 3.3MHz while achieving peak efficiencies
up to 95%. An additional benefit of high-frequency
operation is very low output ripple voltage throughout the
entire load range with the use of a small output capacitor.
The MIC4950 is designed for use with a very small
inductor, down to 1µH, and an output ceramic capacitor as
small as 10µF, without the need for external ripple
injection. A wide range of output capacitor types and
values can also be accommodated.
The MIC4950 supports safe start-up into a pre-biased
output, and offers short-circuit and thermal shutdown
protections.
The MIC4950 is available in 8-Pin SOIC and 10-Pin 3mm
× 4mm DFN packages with an operating junction
temperature range from –40°C to +125°C.
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Features
Input voltage: 2.7V to 5.5V
5A output current
Up to 95% efficiency
Up to 3.3MHz operation
Safe start-up into a pre-biased output
Power Good output
Ultra-fast transient response
Low output voltage ripple
Low RDSON integrated MOSFET switches
0.01µA shutdown current
Thermal shutdown and current limit protection
Output voltage as low as 0.7V
8-Pin SOIC and 3mm × 4mm DFN-10L
–40°C to +125°C junction temperature range
Applications
DTVs
Set-top boxes
Printers
DVD players
Distributed power supplies
Typical Application
Micrel, Inc.
MIC4950
March 20, 2014
2
Revision 1.1
Ordering Information
Part Number(1)
Top Mark
Temperature Range
Package
Lead Finish
MIC4950YFM
4950YFM
–40°C ≤ TJ ≤ +125°C
8-pin SOIC
Pb-Free
MIC4950YFL
MIC4950
–40°C ≤ TJ ≤ +125°C
10-pin 3mm x 4mm DFN(2)
Pb-Free
Note:
1. Other options are available. Contact Micrel for details.
2. DFN is GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Pin Configuration
8-Pin SOIC (FM)
(Top View)
3mm x 4mm DFN (FL)
(Top View)
Pin Description
Pin Number
SOIC-8 (YFM)
Pin Number
DFN-10 (YFL)
Pin Name
Pin Function
1
1, 2, EP
PGND
Power Ground.
2
3, 8
PVIN
Power Input Voltage: Connect a 10µF ceramic capacitor between PVIN and
PGND for input decoupling. Pins 3 and 8 are internally connected in the
DFN-10 package.
3
4
AVIN
Analog Input Voltage: Connect a 1µF ceramic capacitor between AVIN and
AGND to decouple the noise from the internal reference and error comparator.
4
5
AGND
Analog Ground Input: Connect to a quiet ground plane for best operation. Do
not route power switching currents on the AGND net. Connect AGND and
PGND nets together at a single point.
5
6
FB
Feedback (Input): Connect an external divider between VOUT and AGND
(Analog Ground) to program the output voltage.
6
7
PG
Power Good (Output): Open-drain output. A pull-up resistor from this pin to a
voltage source is required to detect an output power-is-good condition.
7
9
EN
Enable (Input): Logic high enables operation of the regulator. Logic low shuts
down the device. Do not leave floating.
8
10
SW
Switch (Output): Internal power MOSFET output switches.
Micrel, Inc.
MIC4950
March 20, 2014
3
Revision 1.1
Absolute Maximum Ratings(3)
PVIN, AVIN Supply Voltage (VIN) ...................... –0.3V to 6V
SW Output Switch Voltage (VSW) ...................... –0.3V to VIN
EN, PG (VEN, VPG) ............................................. –0.3V to VIN
FB Feedback Input Voltage (VFB) ...................... –0.3V to VIN
Storage Temperature Range .................... –65°C to +150°C
ESD Rating(5) ........................................................ 2kV, HBM
Operating Ratings(4)
Supply Voltage (VIN) ......................................... 2.7V to 5.5V
Enable Input Voltage (VEN) .................................... 0V to VIN
Junction Temperature Range (TJ) ....... –40°C ≤ TJ ≤ +125°C
Thermal Resistance
SOIC-8 (JA) ..................................................... 120°C/W
DFN-10 (JA) ...................................................... 35°C/W
Electrical Characteristics(6)
VIN = VEN = 3.3V; L = 1.0µH; CIN = 10µF; COUT = 10µF; TA = 25°C, bold values indicate –40°C≤ TJ ≤ +125°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
VIN
Supply Voltage Range
2.7
5.5
V
VUVLO
Under-Voltage Lockout
Threshold
Turn-On
2.41
2.5
2.61
V
VUVLOH
Under-Voltage Lockout
Hysteresis
400
mV
IQ
Quiescent Current
IOUT = 0mA , FB > 1.2*VFB (Nominal)
0.8
2
mA
ISD
Shutdown Current
VEN = 0V
0.01
2
µA
VFB
Feedback Voltage
0.609
0.625
0.64
V
ILIMIT
Current Limit
FB = 0.9*VFB (Nominal)
5.5
7.5
10
A
LINEREG
Output Voltage Line
Regulation
VIN = 2.7 to 3.5V, VOUTNOM = 1.8V, ILOAD = 20mA
1
%/V
VIN = 4.5V to 5.5V if VOUTNOM ≥ 2.5V, ILOAD =
20mA
LOADREG
Output Voltage Load
Regulation
20mA < ILOAD < 500mA,
VIN = 3.6V if VOUTNOM < 2.5V
0.3
%
20mA < ILOAD < 500mA,
VIN = 5.0V if VOUTNOM ≥ 2.5V
20mA < ILOAD < 5A, VIN = 3.6V if VOUTNOM < 2.5V
1
%
20mA < ILOAD < 5A, VIN = 5.0V if VOUTNOM ≥ 2.5V
RDSON-P
PWM Switch ON-Resistance
ISW = 1A P-Channel MOSFET
30
Ω
RDSON-N
ISW = –1A N-Channel MOSFET
25
tON
Maximum Turn-On Time
VIN = 4.5V, VFB = 0.5V
665
ns
VIN = 3.0V, VFB = 0.5V
1000
VIN = 2.7V, VFB = 0.5V
1120
tOFF
Minimum Turn-Off Time
VIN = 3.0V, VFB = 0.5V
176
ns
tSOFT-ON
Soft Start Time
VOUT = 90% of VOUTNOM
500
µs
VEN
Enable Threshold
Turn-On
0.5
0.8
1.2
V
Notes:
3. Exceeding the absolute maximum ratings may damage the device.
4. The device is not guaranteed to function outside its operating ratings.
5. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
6. Specification for packaged product only.
Micrel, Inc.
MIC4950
March 20, 2014
4
Revision 1.1
Electrical Characteristics(6) (Continued)
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
IEN
Enable Input Current
0.1
1
µA
VOUTPG
Power Good Threshold
Rising
82
88
94
%
VOUTPGH
Power Good Hysteresis
7
%
TSD
Overtemperature Shutdown
150
C
TSDH
Overtemperature Shutdown
Hysteresis
20
C
Micrel, Inc.
MIC4950
March 20, 2014
5
Revision 1.1
Typical Characteristics
60
65
70
75
80
85
90
95
100
0 1 2 3 4 5
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency
vs. Output Current
V
IN
= 5V
VOUT = 3.3V
60
65
70
75
80
85
90
95
100
0 1 2 3 4 5
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency
vs. Output Current
V
IN
= 5.0V
VOUT = 1.8V
V
IN
= 3.3V
VOUT = 1.8V
60
65
70
75
80
85
90
95
100
0 1 2 3 4 5
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency
vs. Output Current
V
IN
= 5V
VOUT = 1.2V
V
IN
= 3.3V
VOUT = 1.2V
0
2
4
6
8
10
12
2.5 3.0 3.5 4.0 4.5 5.0 5.5
CURRENT LIMIT (A)
INPUT VOLTAGE (V)
Current Limit
vs. Input Voltage
VOUT = 1.8V
0
2
4
6
8
10
12
0.0 0.1 0.2 0.3 0.4 0.5
CURRENT LIMIT (A)
FEEDBACK VOLTAGE (V)
Current Limit
vs. Feedback Voltage
V
IN
= 5V
VOUT = 1.8V
-2.0
-1.0
0.0
1.0
2.0
3.0
2.7 3.0 3.3 3.6
LINE REGULATION (%/V)
INPUT VOLTAGE (V)
Line Regulation
vs. Input Voltage
IOUT = 0A
-2
-1
0
1
2
3
4.50 4.75 5.00 5.25 5.50
LINE REGULATION (%/V)
INPUT VOLTAGE (V)
Line Regulation
vs. Input Voltage
V
OUT
= 1.8V
IOUT = 0A
-2
-1
0
1
2
3
2.7 3.0 3.3 3.6
LINE REGULATION (%/V)
INPUT VOLTAGE (V)
Line Regulation
vs. Input Voltage
V
OUT
= 1.8V
IOUT = 1A
-2
-1
0
1
2
3
4.50 4.75 5.00 5.25 5.50
LINE REGULATION (%/V)
INPUT VOLTAGE (V)
Line Regulation
vs. Input Voltage
V
OUT
= 1.8V
IOUT = 1A
Micrel, Inc.
MIC4950
March 20, 2014
6
Revision 1.1
Typical Characteristics (Continued)
0
1
2
3
4
2.5 3.0 3.5 4.0 4.5 5.0 5.5
QUIESCENT CURRENT (mA)
INPUT VOLTAGE (V)
Quiescent Current
vs. Input Voltage
V
FB
> 1.2 x V
FB(NOM)
IOUT = 0A
1.77
1.78
1.79
1.80
1.81
1.82
0 1 2 3 4 5
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage (VIN = 3.3V)
vs. Output Current
V
IN
= 3.3V
VOUT = 1.8V
2.46
2.47
2.48
2.49
2.50
2.51
2.52
0 1 2 3 4 5
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage (VIN = 5V)
vs. Output Current
V
IN
= 5V
VOUT = 2.5V
0.605
0.610
0.615
0.620
0.625
0.630
0.635
-50 -20 10 40 70 100 130
FEEDBACK VOLTAGE (V)
TEMPERATURE (°C)
Feedback Voltage
vs. Temperature
V
IN
= 3.3V
VOUT = 1.8V
IOUT = 0A
2.0
2.2
2.4
2.6
2.8
3.0
-50 -20 10 40 70 100 130
SWITCHING FREQUENCY (MHz)
TEMPERATURE (°C)
Switching Frequency
vs. Temperature
V
IN
= 3.3V
VOUT = 1.8V
IOUT = 0A
1.2
1.6
2.0
2.4
2.8
3.2
0 1 2 3 4 5
SWITCHING FREQUENCY (MHz)
OUTPUT CURRENT (A)
Switching Frequency
vs. Output Current
V
IN
= 5.0V
V
OUT
= 3.3V
1.2
1.6
2.0
2.4
2.8
3.2
3.6
0 1 2 3 4 5
SWITCHING FREQUENCY (MHz)
OUTPUT CURRENT (A)
Switching Frequency
vs. Output Current
V
IN
= 5.0V
VOUT = 1.8V
VIN = 3.3V
VOUT = 1.8V
1.2
1.6
2.0
2.4
2.8
3.2
3.6
0 1 2 3 4 5
SWITCHING FREQUENCY (MHz)
OUTPUT CURRENT (A)
Switching Frequency
vs. Output Current
V
IN
= 5.0V
V
OUT
= 1.2V
VIN = 3.3V
VOUT = 1.2V
Micrel, Inc.
MIC4950
March 20, 2014
7
Revision 1.1
Functional Characteristics
Micrel, Inc.
MIC4950
March 20, 2014
8
Revision 1.1
Functional Characteristics (Continued)
Micrel, Inc.
MIC4950
March 20, 2014
9
Revision 1.1
Functional Block Diagram
Micrel, Inc.
MIC4950
March 20, 2014
10
Revision 1.1
Functional Description
PVIN
The power input (PVIN) pin provides power to the internal
MOSFETs for the switch mode regulator section of the
MIC4950. The input supply operating range is from 2.7V
to 5.5V. A low-ESR ceramic capacitor of at least 10µF is
required for bypass from PVIN to (Power) GND. See the
“Applications Information” section for further details.
AVIN
The analog power input (AVIN) pin provides power to the
internal control and analog supply circuitry. Careful layout
is important to ensure that high-frequency switching noise
caused by PVIN is reduced before reaching AVIN.
Always place a 1µF minimum ceramic capacitor very
close to the IC between AVIN and AGND pins. For
additional high-frequency switching noise attenuation, RC
filtering can be used (R = 10Ω).
EN
A logic high signal on the enable (EN) pin activates the
output of the switch. A logic low on the EN pin
deactivates the output and reduces the supply current to
the nominal 0.01µA. Do not leave this pin floating.
SW
The switch (SW) pin connects directly to one side of the
inductor and provides the current path during switching
cycles. The other end of the inductor is connected to the
load and output capacitor. Due to the high speed
switching on this pin, the switch node should be routed
away from sensitive nodes, whenever possible, to avoid
unwanted injection of noise.
PGND
The power ground (PGND) is the ground return terminal
for the high current in the switching node SW. The
current loop for the PGND should be as short as possible
and kept separate from the AGND net whenever
applicable.
AGND
The analog ground (AGND) is the ground return terminal
for the biasing and control circuitry. The current loop for
the signal ground should be separate from the power
ground (PGND) loop. Refer to the “PCB Layout
Recommendations” section for further details.
PG
The power-is-good (PG) pin is an open-drain output that
indicates logic high when the output voltage is typically
above 88% of its steady-state voltage. A pull-up resistor
of 10kΩ or greater should be connected from PG to
VOUT.
FB
To program the output voltage, an external resistive
divider network is connected to this pin from the output
voltage to AGND, as shown in the Typical Application
circuit on page 1, and is compared to the internal 0.625V
reference within the regulation loop. Equation 1 is used to
program the output voltage:
R2
R1
1VV REFOUT
Eq. 1
Table 1 lists recommended feedback resistor values.
Table 1. Recommended Feedback Resistor Values
VOUT
R1
R2
1.0V
120kΩ
180kΩ
1.2V
274kΩ
294kΩ
1.5V
316kΩ
226kΩ
1.8V
301kΩ
160kΩ
2.5V
316kΩ
105kΩ
3.3V
309kΩ
71.5kΩ
The feedforward capacitor (CF in the Typical Application
schematic) is typically in the range 22pF to 39pF. The
MIC4950 features an internal ripple injection network,
whose current is injected into the FB node and integrated
by CF, thus the waveform at FB is approximately a
triangular ripple. The size of CF dictates the amount of
ripple amplitude at the FB node. Smaller values of CF
yield higher FB ripple amplitude and better stability, but
also somewhat degrade line regulation and transient
response.
Hyper Speed Control™
MIC4950 uses an ON- and OFF-time proprietary ripple-
based control loop, which features three different timers:
Minimum ON Time
Maximum ON Time
Minimum OFF Time
Micrel, Inc.
MIC4950
March 20, 2014
11
Revision 1.1
When the required duty cycle is very low, the required
OFF time is typically far from the Minimum OFF Time limit
(about 176 ns typ). In this case, the MIC4950 operates by
delivering at each switching cycle a determined ON time
(dependent on the input voltage). A new ON time is
invoked by the error comparator when the FB voltage
falls below the regulation threshold. In this mode the
MIC4950 operates as an adaptive Constant-ON-Time
ripple controller, with nearly constant switching
frequency. Regulation takes place by controlling the
valley of the FB ripple waveform.
When higher duty cycles are required, regulation can no
longer be maintained by decreasing the OFF time below
the Minimum OFF Time limit. When this limit is reached,
then the OFF Time is no longer reduced, and the
MIC4950 smoothly transitions to an ON-time modulation
mode. In the ON-time modulation region, frequency
reduces with the increase of the required ON-time/duty
cycle, and regulation finally takes place on the peak of
the FB ripple waveform.
Note that because of the shift of the regulation threshold
between different modes, line regulation might suffer
when the input voltage and/or duty cycle variations force
the MIC4950 to switch form one regulation mode to the
other. In applications where wide input voltage variations
are expected, ensure that the line regulation is adequate
for the intended application.
Micrel, Inc.
MIC4950
March 20, 2014
12
Revision 1.1
Applications Information
The MIC4950 is a highly efficient, 5A synchronous buck
regulator ideally suited for supplying processor core and
I/O voltages from a 5V or 3.3V bus.
Input Capacitor
A 10µF ceramic capacitor or greater should be placed
close to the PVIN pin and PGND pin for bypassing. A
X5R or X7R temperature rating is recommended for the
input capacitor. Take into account C versus bias effect to
estimate the effective capacitance and the input ripple at
the VIN voltage.
Output Capacitor
The MIC4950 is designed for use with a 10µF or greater
ceramic output capacitor. Increasing the output
capacitance will lower output ripple and improve load
transient response. A low equivalent-series resistance
(ESR) ceramic output capacitor is recommended based
on performance, size, and cost. Ceramic capacitors with
X5R or X7R temperature ratings are recommended.
Inductor Selection
When selecting an inductor, it is important to consider the
following factors:
Inductance
Rated current value
Size requirements
DC resistance (DCR)
Core losses
The MIC4950 is designed for use with a 1µH to 2.2µH
inductor. For faster transient response, a 1µH inductor
will yield the best result. For lower output ripple, a 2.2µH
inductor is recommended.
Inductor current ratings are generally given in two
methods: permissible DC current, and saturation current.
Permissible DC current can be rated for a 20°C to 40°C
temperature rise. Saturation current can be rated for a
10% to 30% loss in inductance. Make sure that the
nominal current of the application is well within the
permissible DC current ratings of the inductor, also
depending on the allowed temperature rise. Note that the
inductor permissible DC current rating typically does not
include inductor core losses. These are a very important
contribution to the total inductor core loss and
temperature increase in high-frequency DC-DC
converters, since core losses increase with at least the
square of the excitation frequency. For more accurate
core loss estimation, refer to manufacturers’ datasheets
or websites.
When saturation current is specified, make sure that
there is enough design margin, so that the peak current
does not cause the inductor to enter saturation.
Also pay attention to the inductor saturation characteristic
in current limit. The inductor should not heavily saturate
even in current limit operation, otherwise the current
might instantaneously run away and reach potentially
destructive levels. Typically, ferrite-core inductors exhibit
an abrupt saturation characteristic, while powdered-iron
or composite inductors have a soft-saturation
characteristic.
Peak current can be calculated in Equation 2:
Lf2 /VV1
VII INOUT
OUTOUTPEAK
Eq. 2
As shown by the calculation above, the peak inductor
current is inversely proportional to the switching
frequency and the inductance. The lower the switching
frequency or inductance, the higher the peak current. As
input voltage increases, the peak current also increases.
The size of the inductor depends on the requirements of
the application. Refer to the Typical Application circuit
and Bill of Materials for details.
DC resistance (DCR) is also important. While DCR is
inversely proportional to size, DCR can represent a
significant efficiency loss. Refer to the “Efficiency
Considerations” subsection.
Efficiency Considerations
Efficiency is defined as the amount of useful output
power, divided by the amount of power supplied (see the
Typical Characteristics curves):
100
IV IV
%Efficiency ININ
OUTOUT
Eq. 3
There are two types of losses in switching converters: DC
losses and switching losses. DC losses are simply the
power dissipation of I2R. Power is dissipated in the high-
side switch during the ON cycle. Power loss is equal to
the high-side MOSFET RDSON multiplied by the switch
current squared. During the OFF cycle, the low-side N-
channel MOSFET conducts, also dissipating power.
Device operating current also reduces efficiency. The
product of the quiescent (operating) current and the
supply voltage represents another DC loss. The current
required to drive the gates on and off at high frequency
and the switching transitions make up the switching
losses.
Micrel, Inc.
MIC4950
March 20, 2014
13
Revision 1.1
At the higher currents for which the MIC4950 is designed,
efficiency loss is dominated by MOSFET RDSON and
inductor losses. Higher input supply voltages will increase
the gate-to-source threshold on the internal MOSFETs,
thereby reducing the internal RDSON. This improves
efficiency by reducing DC losses in the device. All but the
inductor losses are inherent to the device. In this case,
inductor selection becomes increasingly critical in
efficiency calculations. As the inductors are reduced in
size, the DC resistance (DCR) can become quite
significant. The DCR losses can be calculated as in
Equation 4.
DCRIP OUTDCR 2
Eq. 4
From that, the loss in efficiency due to inductor DCR and
core losses (PCORE) can be calculated as in Equation 5.
100
PPIV IV
1(%) LossEfficiency COREDCROUTOUT
OUTOUT
Eq. 5
External Ripple Injection
The MIC4950 control loop is ripple-based, and relies on
an internal ripple injection network to generate enough
ripple amplitude at the FB pin when negligible output
voltage ripple is present. The internal ripple injection
network is typically sufficient when recommended R1-R2
and CF values are used. The FB ripple amplitude should
fall in the 20mV to 100mV range.
If significantly lower divider resistors and/or higher CF
values are used, the amount of internal ripple injection
may not be sufficient for stable operation. In this case,
external ripple injection is needed. This is accomplished
by connecting a series Rinj-Cinj circuit between the SW
and the FB pins, as shown in Figure 1.
Figure 1. External Ripple Injection
The injected ripple is calculated using Equation 6,
SW
divINFB(pp) f1
D)-(1DKVΔV
Eq. 6
with Kdiv given by Equation 7
R1//R2R R1//R2
Kinj
div
Eq. 7
and:
VIN = Power stage input voltage
D = VOUT/VIN = Duty cycle
fSW = Switching frequency
= (R1//R2//Rinj) × CF
In Equations 6 and 7, it is assumed that the time constant
associated with CF must be much greater than the
switching period:
1
T
f1
SW
Eq. 8
Micrel, Inc.
MIC4950
March 20, 2014
14
Revision 1.1
Evaluation Board Circuit
Micrel, Inc.
MIC4950
March 20, 2014
15
Revision 1.1
Bill of Materials
Item
Part Number
Manufacturer
Description
Qty.
C1, C2
C2012X5R1A106M125AB
TDK(7)
Ceramic Capacitor, 10µF, 10V, X5R, Size 0805
2
GRM219R61A106ME44
Murata(8)
C3
C1608C0G1H220J080AA
TDK
Ceramic Capacitor, 22pF, 50V, C0G, Size 0603
1
GRM1885C1H220JA01
Murata
C4
C1608X5R1A105M080AC
TDK
Ceramic Capacitor, 1µF, 10V, X5R, Size 0603
1
GRM185R61A105ME26
Murata
C5
DNP, Size 0603
0
C6
DNP, Size 1210
0
C7
DNP, Radial, 8mm diameter polarized capacitor
0
L1
RLF7030T-1R0N6R4
TDK
1µH, 6.4A, 7.3mΩ, L7.3mm x W6.8mm x H3.2mm
1
CLF7045T-1R0N
TDK
1µH, 5.2A, 9.6mΩ, L7.2mm x W6.9mm x H4.5mm
CDRH8D43RT125NP-1R0NC
Sumida(9)
1µH, 7.5A, 7.8mΩ, L8.5mm x W8.3mm x H4.5 mm
R1
CRCW06033013FK
Vishay(10)
Resistor, 301kΩ, Size 0603
1
R2
CRCW06031603FK
Vishay
Resistor, 160kΩ, Size 0603
1
R3
DNP, Size 0603
0
R4
CRCW060310R0FK
Vishay
Resistor, 10Ω, Size 0603
1
R5
CRCW06031002FK
Vishay
Resistor, 10kΩ, Size 0603
1
R6
CRCW06031003FK
Vishay
Resistor, 100kΩ, Size 0603
1
R7
CRCW060349R9FK
Vishay
Resistor, 49.9Ω, Size 0603, for monitoring SW node only
1
U1
MIC4950YFL
Micrel, Inc.(11)
Hyper Speed Control™ 5A Buck Regulator
1
Notes:
7. TDK: www.tdk.com.
8. Murata: www.murata.com.
9. Sumida: www.sumida.com.
10. Vishay: www.vishay.com.
11. Micrel, Inc.: www.micrel.com.
Micrel, Inc.
MIC4950
March 20, 2014
16
Revision 1.1
PCB Layout Recommendations
Top Layer
Bottom Layer
Micrel, Inc.
MIC4950
March 20, 2014
18
Revision 1.1
Package Information Recommended Landing Pattern(12) (Continued)
10-Pin DFN 3mm x 4mm (FL)
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.
