MICREL MIC23153YMT

MIC23153
4MHz PWM 2A Buck Regulator with
HyperLight Load™ and Power Good
General Description
Features
The MIC23153 is a high efficiency 4MHz 2A synchronous
buck regulator with HyperLight Load™ mode, Power Good
output indicator, and programmable soft-start. HyperLight
Load™ provides very high efficiency at light loads and
ultra-fast transient response which makes the MIC23153
perfectly suited for supplying processor core voltages. An
additional benefit of this proprietary architecture is very low
output ripple voltage throughout the entire load range with
the use of small output capacitors. The tiny 2.5mm x
2.5mm Thin MLF® package saves precious board space
and requires only four external components.
The MIC23153 is designed for use with a very small
inductor, down to 0.47µH, and an output capacitor as small
as 2.2 µF that enables a total solution size, less than 1mm
in height.
The MIC23153 has a very low quiescent current of 22µA
and achieves a peak efficiency of 93% in continuous
conduction mode. In discontinuous conduction mode, the
MIC23153 can achieve 85% efficiency at 1mA.
The MIC23153 is available in 10-pin 2.5mm x 2.5mm Thin
MLF® package with an operating junction temperature
range from –40°C to +125°C.
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
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Input voltage: 2.7V to 5.5V
Output voltage: fixed or adjustable (0.62V to 3.6V)
Up to 2A output current
Up to 93% peak efficiency
85% typical efficiency at 1mA
Power Good output
Programmable soft-start
22µA typical quiescent current
4MHz PWM operation in continuous mode
Ultra fast transient response
Low ripple output voltage
− 35mVpp ripple in HyperLight Load™ mode
− 5mV output voltage ripple in full PWM mode
Fully integrated MOSFET switches
0.01µA shutdown current
Thermal shutdown and current limit protection
10-pin 2.5mm x 2.5mm Thin MLF®
–40°C to +125°C junction temperature range
Applications
• Solid State Drives (SSD)
• Mobile handsets
• Portable media/MP3 players
• Portable navigation devices (GPS)
• WiFi/WiMax/WiBro modules
• Wireless LAN cards
• Portable applications
____________________________________________________________________________________________________________
Typical Application
Fixed Output Voltage
Adjustable Output Voltage
HyperLight Load is a trademark of Micrel, Inc.
MLF and MicroLeadFrame are registered trademark Amkor Technology 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
December 2009
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MIC23153
Ordering Information
Marking
Code
Part Number
Nominal Output
Voltage
Junction
Temp. Range
Package
MIC23153-GYMT
WEG
1.8V
–40°C to +125°C
10-Pin 2.5mm x 2.5mm Thin MLF®
MIC23153YMT
WEA
Adjustable
–40°C to +125°C
10-Pin 2.5mm x 2.5mm Thin MLF®
Notes:
1. Other options available (1V - 3.3V). Contact Micrel Marketing for details.
®
2. Thin MLF is GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
®
3. Thin MLF ▲ = Pin 1 identifier.
Pin Configuration
2.5mm x 2.5mm Thin MLF® (MT)
Fixed Output Voltage
(Top View)
2.5mm x 2.5mm Thin MLF® (MT)
Adjustable Output Voltage
(Top View)
Pin Description
Pin Number
Pin Number
(Fixed)
(Adjustable)
1
1
SW
Switch (Output): Internal power MOSFET output switches.
2
2
EN
Enable (Input): Logic high enables operation of the regulator. Logic low
will shut down the device. Do not leave floating.
3
3
SNS
4
-
NC
Not Internally Connected.
-
4
FB
Feedback: Connect a resistor divider from the output to ground to set the
output voltage.
5
5
PG
Power Good: Open drain output for the power good indicator. Use a pullup resistor from this pin to a voltage source to detect a power good
condition.
6
6
SS
Soft Start: Place a capacitor from this pin to ground to program the soft
start time. Do not leave floating, 100pF minimum CSS is required.
7
7
AGND
Analog Ground: Connect to central ground point where all high current
paths meet (CIN, COUT, PGND) for best operation.
8,9
8,9
VIN
10
10
PGND
December 2009
Pin Name
Pin Function
Sense: Connect to VOUT as close to output capacitor as possible to sense
output voltage.
Input Voltage: Connect a capacitor to ground to decouple the noise.
Power Ground.
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MIC23153
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VIN)... …………………………..2.7V to 5.5V
Enable Input Voltage (VEN) .. ……………………….0V to VIN
Sense Voltage (VSNS) ..................................... 0.62V to 3.6V
Junction Temperature Range (TJ)... ….-40°C ≤ TJ ≤ +125°C
Thermal Resistance
2.5mm x 2.5mm Thin MLF-10 (θJA) ...................90°C/W
2.5mm x 2.5mm Thin MLF-10 (θJC) ...................63°C/W
Supply Voltage (VIN) ........................................... -0.3V to 6V
Sense Voltage (VSNS) .........................................-0.3V to VIN
Output Switch Voltage (VSW) ..............................-0.3V to VIN
Enable Input Voltage (VEN).. ..............................-0.3V to VIN
Power Good Voltage (VPG).................................-0.3V to VIN
Storage Temperature Range .. ……………-65°C to +150°C
Lead temperature (soldering, 10 sec.) ....................... 260°C
ESD Rating(3) ................................................. ESD Sensitive
Electrical Characteristics(4)
TA = 25°C; VIN = VEN = 3.6V; L = 1.0µH; COUT = 4.7µF unless otherwise specified.
Bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted.
Parameter
Condition
Min
(turn-on)
2.45
Supply Voltage Range
Under-Voltage Lockout Threshold
IOUT = 0mA , SNS > 1.2 * VOUT Nominal
Shutdown Current
VEN = 0V; VIN = 5.5V
VIN = 3.6V if VOUTNOM < 2.5V, ILOAD = 20mA
VIN = 4.5V if VOUTNOM ≥ 2.5V, ILOAD = 20mA
ILOAD = 20mA
Current Limit
SNS = 0.9*VOUTNOM
Output Voltage Line Regulation
VIN = 3.6V to 5.5V if VOUTNOM < 2.5V, ILOAD = 20mA
VIN = 4.5V to 5.5V if VOUTNOM ≥ 2.5V, ILOAD = 20mA
20mA < ILOAD < 500mA, VIN = 3.6V if VOUTNOM < 2.5V
20mA < ILOAD < 500mA, VIN = 5.0V if VOUTNOM ≥ 2.5V
20mA < ILOAD < 1A, VIN = 3.6V if VOUTNOM < 2.5V
20mA < ILOAD < 1A, VIN = 5.0V if VOUTNOM ≥ 2.5V
ISW = 100mA PMOS
Output Voltage Load Regulation
PWM Switch ON-Resistance
Units
5.5
V
2.55
2.65
75
Quiescent Current
Feedback Regulation Voltage
Max
2.7
Under-Voltage Lockout Hysteresis
Output Voltage Accuracy
Typ
IOUT = 120mA
Soft Start Time
Soft Start Current
22
45
µA
0.01
5
µA
+2.5
%
0.635
V
-2.5
0.6045
0.62
2.2
3.3
A
0.3
%/V
0.3
%
0.7
%
0.2
ISW = -100mA NMOS
Switching Frequency
V
mV
Ω
0.19
4
MHz
VOUT = 90%, CSS = 470pF
320
µs
VSS = 0V
2.7
µA
Power Good Threshold (Rising)
86
Power Good Threshold Hysteresis
Power Good Delay Time
Rising
Enable Threshold
Turn-On
92
96
%
7
%
68
µs
0.9
1.2
V
Enable Input Current
0.1
2
µA
Over-temperature Shutdown
160
°C
Over-temperature Shutdown
Hysteresis
20
°C
0.5
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF.
4. Specification for packaged product only.
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Typical Characteristics
Efficiency v s. Output Current
VOUT = 3.3V @ 25°C
100%
100%
90%
90%
80%
80%
VIN = 5V
60%
EFFICIENCY (%)
VIN = 3V
50%
VIN = 3.6V
40%
VIN = 5V
50%
VIN = 5.5V
40%
30%
20%
20%
10%
10%
0%
10
100
1000
OUT PUT CURRENT (mA)
VIN = 4.2V
60%
30%
1
100000
70%
1
10
100
1000
OUT PUT CURRENT (mA)
10000
100
2.5
2.0
1.5
1.0
TCASE = 25°C
0.0
1.900
1.875
25
OUTPUT VOLTAGE (V)
SHUTDOWN CURRENT (nA)
3.0
20
15
10
5
3.0
3.5
4.0
4.5
INPUT VOLT AGE (V)
5.0
5.5
3.0
3.5
4.0
4.5
5.0
INPUT VOLT AGE (V)
1.80
IOUT = 1A
1.70
3.5
4.0
4.5
5.0
INPUT VOLT AGE (V)
1.900
1.875
1.875
1.850
1.850
1.825
1.800
1.775
1.750
1.725
5.5
90
80
1.83
70
PG DELAY (µs)
1.81
1.80
1.79
1.78
0.02
0.04
0.06
0.08
OUT PUT CURRENT (A)
December 2009
VIN = 3.6V
0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9
OUT PUT CURRENT (A)
90%
PG Rising
PG Falling
PG Rising
89%
88%
87%
86%
85%
84%
PG Falling
83%
82%
81%
0
0 20 40 60 80 100 120
T EM PERAT URE (°C)
1.750
91%
30
1.76
ILOAD = 20mA
1.775
PG Thresholds
v s. Input Voltage
40
10
1.75
1.800
0.1
50
20
5.5
1.700
60
1.77
3.5
4.0
4.5
5.0
INPUT VOLT AGE (V)
1.825
PG Delay Tim e
v s. Input Voltage
1.84
1.82
3.0
1.725
VIN = 3.6V
0
1.85
IOUT = 130mA
Output Voltage v s.
Output Current (CCM)
1.900
Output Voltage
v s. Temperature
-40 -20
IOUT = 1mA
1.750
2.5
1.700
3.0
1.775
5.5
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
IOUT = 300mA
2.5
1.800
Output Voltage v s.
Output Current (HLL)
1.90
1.75
IOUT = 20mA
1.825
1.700
2.5
Line Regulation
(High Loads)
1.85
1.850
1.725
TCASE = 25°C
0
2.5
10000
100000 1000000
CSS (pF)
Line Regulation
(Low Loads)
30
0.5
1000
Shutdown Current
v s. Input Voltage
3.5
CURRENT LIM IT (A)
100
VIN = 3.6V
10000
4.0
OUTPUT VOLTAGE (V)
1000
1
Current Limit
v s. Input Voltage
OUTPUT VOLTAGE (V)
10000
10
PG THRESHOLD (% of VREF)
EFFICIENCY (%)
70%
VOUT Rise Tim e
v s. C SS
1000000
RISE TIM E (µs)
Efficiency v s. Output Current
VOUT = 1.8V @ 25°C
2.5
3.0
3.5
4.0
4.5
5.0
INPUT VOLT AGE (V)
4
5.5
2.5
3.0
3.5
4.0
4.5
5.0
INPUT VOLT AGE (V)
5.5
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MIC23153
Typical Characteristics (Continued)
UVLO Threshold
v s. Tem perature
Enable Threshold
v s. Input Voltage
UVLO_ON
2.54
VEN THRESHOLD (V)
UVLO THRESHOLD (V)
2.55
2.53
2.52
2.51
2.50
2.49
UVLO_OFF
2.48
1.2
1.2
1.1
1.1
VEN THRESHOLD (V)
2.56
Enable Threshold
v s. Temperature
1.0
0.9
0.8
0.7
0.9
0.8
0.7
0.6
0.6
2.47
1.0
TCASE = 25°C
2.46
VIN = 3.3V
0.5
-40 -20
0 20 40 60 80 100 120
T EM PERAT URE (°C)
0.5
2.5
3.0
3.5
4.0
4.5
INPUT VOLT AGE (V)
5.0
5.5
-40 -20
0 20 40 60 80 100 120
T EM PERAT URE (°C)
Feedback Voltage
v s. Tem perature
Switching Frequency
v s. Load Current
0.65
10000
1000
100
FEEDBACK VOLTAGE (V)
SW FREQUENCY (kHz)
L = 2.2µH
L = 1µH
10
1
VOUT = 1.8V
0.1
0.0001
0.001
0.01
0.1
LOAD CURRENT (A)
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1
10
0.64
0.63
VIN = 3.6V
VIN = 5.5V
0.62
VIN = 2.6V
0.61
0.60
0.59
-40 -20
0
20 40 60 80 100 120
T EM PERAT URE (°C)
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MIC23153
Functional Characteristics
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Functional Characteristics (Continued)
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Functional Characteristics (Continued)
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Functional Diagram
Figure 1. Simplified MIC23153 Functional Block Diagram – Fixed Output Voltage
Figure 2. Simplified MIC23153 Functional Block Diagram – Adjustable Output Voltage
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MIC23153
current in PWM mode. The current loop for the power
ground should be as small as possible and separate
from the analog ground (AGND) loop as applicable.
Refer to the layout recommendations for more details.
Functional Description
VIN
The input supply (VIN) provides power to the internal
MOSFETs for the switch mode regulator along with the
internal control circuitry. The VIN operating range is 2.7V
to 5.5V so an input capacitor, with a minimum voltage
rating of 6.3V, is recommended. Due to the high
switching speed, a minimum 2.2µF bypass capacitor
placed close to VIN and the power ground (PGND) pin is
required. Refer to the layout recommendations for
details.
PG
The power good (PG) pin is an open drain output which
indicates logic high when the output voltage is typically
above 92% of its steady state voltage. A pull-up resistor
of more than 5kOhms should be connected from PG to
VOUT.
SS
The soft start (SS) pin is used to control the output
voltage ramp up time. The approximate equation for the
ramp time in milliseconds is 270x103 x ln(10) x CSS. For
example, for a CSS = 470pF, Trise ~ 300µs. See the
Typical Characteristics curve for a graphical guide. The
minimum recommended value for CSS is 100pF.
EN
A logic high signal on the enable pin activates the output
voltage of the device. A logic low signal on the enable
pin deactivates the output and reduces supply current to
0.01µA. MIC23153 features external soft-start circuitry
via the soft start (SS) pin that reduces in-rush current
and prevents the output voltage from overshooting at
start up. Do not leave the EN pin floating.
FB
The feedback (FB) pin is provided for the adjustable
voltage option (no internal connection for fixed options).
This is the control input for programming the output
voltage. A resistor divider network is connected to this
pin from the output and is compared to the internal
0.62V reference within the regulation loop.
The output voltage can be programmed between 0.65V
and 3.6V using the following equation:
SW
The switch (SW) connects directly to one end of the
inductor and provides the current path during switching
cycles. The other end of the inductor is connected to the
load, SNS pin and output capacitor. Due to the high
speed switching on this pin, the switch node should be
routed away from sensitive nodes whenever possible.
R1 ⎞
⎛
VOUT = VREF ⋅ ⎜1 +
⎟
R2 ⎠
⎝
SNS
The sense (SNS) pin is connected to the output of the
device to provide feedback to the control circuitry. The
SNS connection should be placed close to the output
capacitor. Refer to the layout recommendations for more
details.
Where: R1 is the top resistor, R2 is the bottom resistor.
Example feedback resistor values:
AGND
The analog ground (AGND) is the ground path 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 layout recommendations for
more details.
VOUT
R1
R2
1.2V
274k
294k
1.5V
316k
221k
1.8V
301k
158k
2.5V
324k
107k
3.3V
309k
71.5k
PGND
The power ground pin is the ground path for the high
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MIC23153
in inductance. Ensure the inductor selected can handle
the maximum operating current. When saturation current
is specified, make sure that there is enough margin so
that the peak current does not cause the inductor to
saturate. Peak current can be calculated as follows:
Application Information
The MIC23153 is a high performance DC-to-DC step
down regulator offering a small solution size. Supporting
an output current up to 2A inside a tiny 2.5mm x 2.5mm
Thin MLF® package, the IC requires only three external
components while meeting today’s miniature portable
electronic device needs. Using the HyperLight Load™
switching scheme, the MIC23153 is able to maintain
high efficiency throughout the entire load range while
providing ultra-fast load transient response. The
following sections provide additional device application
information.
⎡
⎛ 1 − VOUT /VIN ⎞⎤
⎟⎟⎥
IPEAK = ⎢IOUT + VOUT ⎜⎜
⎝ 2 × f × L ⎠⎦
⎣
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 the 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.
The transition between high loads (CCM) to Hyperlight
load (HLL) mode is determined by the inductor ripple
current and the load current.
Input Capacitor
A 2.2µF ceramic capacitor or greater should be placed
close to the VIN pin and PGND pin for bypassing. A
Murata GRM188R60J475ME84D, size 0603, 4.7µF
ceramic capacitor is recommended based upon
performance, size and cost. A X5R or X7R temperature
rating is recommended for the input capacitor. Y5V
temperature rating capacitors, aside from losing most of
their capacitance over temperature, can also become
resistive at high frequencies. This reduces their ability to
filter out high frequency noise.
Output Capacitor
The MIC23153 is designed for use with a 2.2µF or
greater ceramic output capacitor. Increasing the output
capacitance will lower output ripple and improve load
transient response but could also increase solution size
or cost. A low equivalent series resistance (ESR)
ceramic output capacitor such as the Murata
GRM188R60J475ME84D, size 0603, 4.7µF ceramic
capacitor is recommended based upon performance,
size and cost. Both the X7R or X5R temperature rating
capacitors are recommended. The Y5V and Z5U
temperature rating capacitors are not recommended due
to their wide variation in capacitance over temperature
and increased resistance at high frequencies.
The diagram shows the signals for high side switch drive
(HSD) for Ton control, the Inductor current and the low
side switch drive (LSD) for Toff control.
In HLL mode, the inductor is charged with a fixed Ton
pulse on the high side switch (HSD). After this, the LSD
is switched on and current falls at a rate VOUT/L. The
controller remains in HLL mode while the inductor falling
current is detected to cross approximately -50mA. When
the LSD (or Toff) time reaches its minimum and the
inductor falling current is no longer able to reach this 50mA threshold, the part is in CCM mode and switching
at a virtually constant frequency.
Once in CCM mode, the Toff time will not vary.
Therefore, it is important to note that if L is large enough,
the HLL transition level will not be triggered.
That inductor is:
V
⋅135ns
LMAX = OUT
2 ⋅ 50mA
Inductor Selection
When selecting an inductor, it is important to consider
the following factors (not necessarily in the order of
importance):
•
Inductance
•
Rated current value
•
Size requirements
•
DC resistance (DCR)
The MIC23153 is designed for use with a 0.47µH to
2.2µH inductor. For faster transient response, a 0.47µH
inductor will yield the best result. For lower output ripple,
a 2.2µH inductor is recommended.
Maximum current ratings of the inductor are generally
given in two methods; permissible DC current and
saturation current. Permissible DC current can be rated
either for a 40°C temperature rise or a 10% to 20% loss
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MIC23153
output currents.
Over 100mA, 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 which 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 follows:
Compensation
The MIC23153 is designed to be stable with a 0.47µH to
2.2µH inductor with a 4.7µF ceramic (X5R) output
capacitor.
Duty Cycle
The typical maximum duty cycle of the MIC23153 is
80%.
Efficiency Considerations
Efficiency is defined as the amount of useful output
power, divided by the amount of power supplied.
⎛V
×I
Efficiency % = ⎜⎜ OUT OUT
⎝ VIN × IIN
PDCR = IOUT2 x DCR
From that, the loss in efficiency due to inductor
resistance can be calculated as follows:
⎞
⎟⎟ × 100
⎠
Maintaining high efficiency serves two purposes. It
reduces power dissipation in the power supply, reducing
the need for heat sinks and thermal design
considerations and it reduces consumption of current for
battery-powered applications. Reduced current draw
from a battery increases the devices operating time and
is critical in hand held devices.
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 Nchannel 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 driving the gates on and off at a constant 4MHz
frequency and the switching transitions make up the
switching losses.
⎡ ⎛
VOUT × IOUT
Efficiency Loss = ⎢1 − ⎜⎜
⎢⎣ ⎝ VOUT × IOUT + PDCR
Efficiency loss due to DCR is minimal at light loads and
gains significance as the load is increased. Inductor
selection becomes a trade-off between efficiency and
size in this case.
HyperLight Load™ Mode
MIC23153 uses a minimum on and off time proprietary
control loop (patented by Micrel). When the output
voltage falls below the regulation threshold, the error
comparator begins a switching cycle that turns the
PMOS on and keeps it on for the duration of the
minimum-on-time. This increases the output voltage. If
the output voltage is over the regulation threshold, then
the error comparator turns the PMOS off for a minimumoff-time until the output drops below the threshold. The
NMOS acts as an ideal rectifier that conducts when the
PMOS is off. Using a NMOS switch instead of a diode
allows for lower voltage drop across the switching device
when it is on. The asynchronous switching combination
between the PMOS and the NMOS allows the control
loop to work in discontinuous mode for light load
operations. In discontinuous mode, the MIC23153 works
in pulse frequency modulation (PFM) to regulate the
output. As the output current increases, the off-time
decreases, thus provides more energy to the output.
This switching scheme improves the efficiency of
MIC23153 during light load currents by only switching
when it is needed. As the load current increases, the
MIC23153 goes into continuous conduction mode (CCM)
and switches at a frequency centered at 4MHz. The
equation to calculate the load when the MIC23153 goes
into continuous conduction mode may be approximated
by the following formula:
Efficiency v s. Output Current
VOUT = 1.8V @ 25°C
1.00
VIN = 3V
0.90
EFFICIENCY (%)
0.80
0.70
0.60
VIN = 5V
VIN = 3.6V
0.50
0.40
0.30
0.20
0.10
0.00001
0.001
0.1
OUT PUT CURRENT (A)
10
Figure 2. Efficiency Under Load
⎛ (V − VOUT ) × D ⎞
⎟⎟
ILOAD > ⎜⎜ IN
2L × f
⎝
⎠
As shown in the previous equation, the load at which the
MIC23153 transitions from HyperLight Load™ mode to
The figure above shows an efficiency curve. From no
load to 100mA, efficiency losses are dominated by
quiescent current losses, gate drive and transition
losses. By using the HyperLight Load™ mode, the
MIC23153 is able to maintain high efficiency at low
December 2009
⎞⎤
⎟⎥ × 100
⎟
⎠⎥⎦
12
M9999-121409-A
Micrel Inc.
MIC23153
PWM mode is a function of the input voltage (VIN), output
voltage (VOUT), duty cycle (D), inductance (L) and
frequency (f). As shown in Figure 3, as the Output
Current increases, the switching frequency also
increases until the MIC23153 goes from HyperLight
Load™ mode to PWM mode at approximately 120mA.
The MIC23153 will switch at a relatively constant
frequency around 4MHz once the output current is over
120mA.
Switching Frequency
v s. Load Current
10000
SW FREQUENCY (kHz)
L = 2.2µH
1000
100
L = 1µH
10
1
VOUT = 1.8V
0.1
0.0001
0.001
0.01
0.1
1
10
LOAD CURRENT (A)
Figure 3. SW Frequency vs. Output Current
December 2009
13
M9999-121409-A
Micrel Inc.
MIC23153
Typical Application Circuit (Fixed Output)
Bill of Materials
Item
C1
Part Number
C1608X5R0J475K
Manufacturer
TDK
Description
Qty.
(1)
1
GRM188R60J475KE19D
Murata(2)
C1608X5R0J475K
TDK
GRM188R60J475KE84D
Murata
C1608NPO0J471K
TDK
Ceramic Capacitor, 470pF, 6.3V, NPO, Size 0603
VLS3012ST-1R0N1R9
TDK
1µH, 2A, 60mΩ, L3.0mm x W3.0mm x H1.0mm
LQH44PN1R0NJ0
Murata
R3
CRCW06031002FKEA
Vishay(3)
Resistor,10k, Size 0603
1
R4
CRCW06031002FKEA
Vishay
Resistor,10k, Size 0603
1
U1
MIC23153-xYMT
Micrel, Inc.(4)
4MHz 2A Buck Regulator with HyperLight Load™ Mode
1
C2
C3
L1
Ceramic Capacitor, 4.7µF, 6.3V, X5R, Size 0603
1
1
1
1µH, 2.8A, 50mΩ, L4.0mm x W4.0mm x H1.2mm
Notes:
1. TDK: www.tdk.com
2. Murata: www.murata.com
3. Vishay: www.vishay.com
4. Micrel, Inc.: www.micrel.com
December 2009
14
M9999-121409-A
Micrel Inc.
MIC23153
Typical Application Circuit (Adjustable Output)
Bill of Materials
Item
C1
Part Number
C1608X5R0J475K
Manufacturer
TDK
GRM188R60J475KE19D
Murata(2)
C1608X5R0J475K
TDK
GRM188R60J475KE84D
Murata
C3
C1608NPO0J471K
TDK
C4
-
-
VLS3010ST-1R0N1R9
TDK
C2
L1
LQH44PN1R0NJ0
Description
Qty.
(1)
1
Ceramic Capacitor, 4.7µF, 6.3V, X5R, Size 0603
1
Ceramic Capacitor, 470pF, 6.3V, NPO, Size 0603
1
Not Fitted (NF)
0
1µH, 2A, 60mΩ, L3.0mm x W3.0mm x H1.0mm
(2)
Murata
1µH, 2.8A, 50mΩ, L4.0mm x W4.0mm x H1.2mm
1
R1
CRCW06033013FKEA
Vishay(3)
Resistor,301k, Size 0603
1
R2
CRCW06031583FKEA
Vishay
Resistor,158k, Size 0603
1
R3
CRCW06031002FKEA
Vishay
Resistor,10k, Size 0603
1
R4
CRCW06031002FKEA
Vishay
Resistor,10k, Size 0603
1
U1
MIC23153-AYMT
Micrel, Inc.(4)
4MHz 2A Buck Regulator with HyperLight Load™ Mode
1
Notes:
1. TDK: www.tdk.com
2. Murata : www.murata.com
3. Vishay: www.vishay.com
4. Micrel, Inc.: www.micrel.com
December 2009
15
M9999-121409-A
Micrel Inc.
MIC23153
PCB Layout Recommendations
Top Layer
Bottom Layer
December 2009
16
M9999-121409-A
Micrel Inc.
MIC23153
Package Information
10-Pin 2.5mm x 2.5mm Thin MLF
December 2009
17
®
M9999-121409-A
Micrel Inc.
MIC23153
Recommended Land Pattern
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
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its
use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
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.
© 2009 Micrel, Incorporated.
December 2009
18
M9999-121409-A