MIC23153

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
September 2011
M9999-092211-B
Micrel Inc.
MIC23153
Ordering Information
Marking
Code
Part Number
Nominal Output Voltage
Junction
Temperature 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
Sense: Connect to VOUT as close to output capacitor as possible to sense output
voltage.
4
-
NC
Not Internally Connected.
Pin Name
Pin Function
-
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 pull-up 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
September 2011
Input Voltage: Connect a capacitor to ground to decouple the noise.
Power Ground.
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M9999-092211-B
Micrel Inc.
MIC23153
Absolute Maximum Ratings(1)
Operating Ratings(2)
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
Junction Temperature (TJ) .......................................+150°C
Storage Temperature Range (TS) .............−65°C to +150°C
Lead Temperature (soldering, 10s)............................ 260°C
ESD Rating(3) ................................................. ESD Sensitive
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
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.
Supply Voltage Range
Undervoltage Lockout Threshold
2.7
(Turn-On)
2.45
Undervoltage Lockout Hysteresis
IOUT = 0mA , SNS > 1.2 * VOUT Nominal
Shutdown Current
VEN = 0V; VIN = 5.5V
Output Voltage Accuracy
VIN = 3.6V if VOUTNOM < 2.5V, ILOAD = 20mA
VIN = 4.5V if VOUTNOM ≥ 2.5V, ILOAD = 20mA
Feedback Regulation Voltage
ILOAD = 20mA
Output Voltage Line Regulation
Output Voltage Load Regulation
PWM Switch ON-Resistance
2.55
Max.
Units
5.5
V
2.65
V
75
Quiescent Current
Current Limit
Typ.
SNS = 0.9*VOUTNOM
mV
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
%
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
0.2
ISW = −100mA NMOS
Ω
0.19
Switching Frequency
IOUT = 120mA
4
Soft-Start Time
VOUT = 90%, CSS = 470pF
320
µs
Soft-Start Current
VSS = 0V
2.7
µA
Power Good Threshold (Rising)
86
Power Good Threshold Hysteresis
92
MHz
96
7
Power Good Delay Time
Rising
Enable Threshold
Turn-On
%
%
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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MIC23153
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)
September 2011
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
0.5
2.5
0 20 40 60 80 100 120
T EM PERAT URE (°C)
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)
September 2011
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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MIC23153
Functional Characteristics (Continued)
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Functional Characteristics (Continued)
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MIC23153
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
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 5kΩ should be connected from PG to VOUT.
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.
SS
The soft start (SS) pin is used to control the output
voltage ramp up time. The approximate equation for the
ramp time in seconds 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 ⎠
⎝
where:
R1 is the top resistor, R2 is the bottom resistor.
Example feedback resistor values:
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
details.
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
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
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 details.
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MIC23153
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
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 stepdown 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
⎣
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.
⎞⎤
⎟⎟⎥
⎠⎦
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.
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.
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 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.
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.
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MIC23153
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:
L MAX
1.00
0.90
EFFICIENCY (%)
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
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
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.
⎞
⎟⎟ × 100
⎠
PDCR = IOUT2 x DCR
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.
September 2011
VIN = 3V
0.80
V
× 135ns
= OUT
2 × 50mA
⎛V
×I
Efficiency % = ⎜⎜ OUT OUT
⎝ VIN × IIN
Efficiency v s. Output Current
VOUT = 1.8V @ 25°C
From that, the loss in efficiency due to inductor
resistance can be calculated as follows:
⎡ ⎛
VOUT × IOUT
Efficiency Loss = ⎢1 − ⎜⎜
⎣⎢ ⎝ VOUT × IOUT + PDCR
⎞⎤
⎟⎥ × 100
⎟
⎠⎦⎥
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.
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MIC23153
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:
ILOAD
As shown in the previous equation, the load at which the
MIC23153 transitions from HyperLight Load™ mode to
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
100
L = 1µH
10
1
0.1
0.0001
VOUT = 1.8V
0.001
0.01
0.1
1
10
LOAD CURRENT (A)
Figure 3. SW Frequency vs. Output Current
⎛ (V − VOUT ) × D ⎞
⎟⎟
> ⎜⎜ IN
2L × f
⎝
⎠
September 2011
1000
13
M9999-092211-B
Micrel Inc.
MIC23153
Typical Application Circuit (Fixed Output)
Bill of Materials
Item
C1
C2
C3
L1
Part Number
C1608X5R0J475K
GRM188R60J475KE19D
C1608X5R0J475K
GRM188R60J475KE84D
C1608NPO0J471K
VLS3012ST-1R0N1R9
Manufacturer
TDK
Description
Qty.
(1)
1
(2)
Murata
TDK(1)
Ceramic Capacitor, 4.7µF, 6.3V, X5R, Size 0603
1
(2)
Murata
TDK(1)
TDK
(1)
Ceramic Capacitor, 470pF, 6.3V, NPO, Size 0603
1
1µH, 2A, 60mΩ, L3.0mm x W3.0mm x H1.0mm
1
LQH44PN1R0NJ0
Murata(2)
1µH, 2.8A, 50mΩ, L4.0mm x W4.0mm x H1.2mm
CRCW06031002FKEA
Vishay(3)
Resistor,10k, Size 0603
1
R4
CRCW06031002FKEA
(3)
Resistor,10k, Size 0603
1
U1
MIC23153-xYMT
4MHz 2A Buck Regulator with HyperLight Load™ Mode
1
R3
Vishay
Micrel, Inc.(4)
Notes:
1. TDK: www.tdk.com.
2. Murata: www.murata.com.
3. Vishay: www.vishay.com.
4. Micrel, Inc.: www.micrel.com.
September 2011
14
M9999-092211-B
Micrel Inc.
MIC23153
Typical Application Circuit (Adjustable Output)
Bill of Materials
Item
C1
C2
C3
Part Number
C1608X5R0J475K
GRM188R60J475KE19D
C1608X5R0J475K
GRM188R60J475KE84D
C1608NPO0J471K
−
C4
L1
VLS3010ST-1R0N1R9
Manufacturer
Description
Qty.
TDK(1)
Murata(2)
TDK(1)
1
Ceramic Capacitor, 4.7µF, 6.3V, X5R, Size 0603
1
Murata(2)
TDK(1)
−
TDK
(1)
(2)
Ceramic Capacitor, 470pF, 6.3V, NPO, Size 0603
1
Not Fitted (NF)
0
1µH, 2A, 60mΩ, L3.0mm x W3.0mm x H1.0mm
1
LQH44PN1R0NJ0
Murata
1µH, 2.8A, 50mΩ, L4.0mm x W4.0mm x H1.2mm
R1
CRCW06033013FKEA
Vishay(3)
Resistor,301k, Size 0603
1
R2
CRCW06031583FKEA
Vishay(3)
Resistor,158k, Size 0603
1
CRCW06031002FKEA
(3)
Resistor,10k, Size 0603
1
Resistor,10k, Size 0603
1
4MHz 2A Buck Regulator with HyperLight Load™ Mode
1
R3
R4
CRCW06031002FKEA
U1
MIC23153-AYMT
Vishay
(3)
Vishay
Micrel, Inc.(4)
Notes:
1. TDK: www.tdk.com.
2. Murata : www.murata.com.
3. Vishay: www.vishay.com.
4. Micrel, Inc.: www.micrel.com.
September 2011
15
M9999-092211-B
Micrel Inc.
MIC23153
PCB Layout Recommendations
Top Layer
Bottom Layer
September 2011
16
M9999-092211-B
Micrel Inc.
MIC23153
Package Information
10-Pin 2.5mm x 2.5mm Thin MLF®
September 2011
17
M9999-092211-B
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
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
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© 2009 Micrel, Incorporated.
September 2011
18
M9999-092211-B