MIC23150
4MHz, PWM, 2A Buck Regulator with
HyperLight Load®
General Description
The MIC23150 is a high-efficiency 4MHz 2A synchronous
®
buck regulator with HyperLight Load mode. HyperLight
Load provides very high efficiency at light loads and ultrafast transient response which is 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 2mm × 2mm Thin DFN
(TDFN) package saves precious board space and requires
only three external components.
The MIC23150 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
height.
The MIC23150 has a very low quiescent current of 23µA
and achieves a peak efficiency of 93% in continuous
conduction mode. In discontinuous conduction mode, the
MIC23150 can achieve 87% efficiency at 1mA.
The MIC23150 is available in 8-pin 2mm × 2mm Thin DFN
package 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.
HyperLight Load®
Features
•
•
•
•
•
•
•
•
•
•
•
•
Input voltage: 2.7V to 5.5V
2A output current
Up to 93% peak efficiency
87% typical efficiency at 1mA
23µA typical quiescent current
4MHz PWM operation in continuous mode
Ultra-fast transient response
Low ripple output voltage
− 14mVpp ripple in HyperLight Load mode
− 5mV output voltage ripple in full PWM mode
0.01µA shutdown current
Thermal-shutdown and current-limit protection
Output voltage as low as 0.95V
8-pin 2mm × 2mm Thin DFN (TDFN) package
Applications
•
•
•
•
•
•
Mobile handsets
Portable media/MP3 players
Portable navigation devices (GPS)
WiFi/WiMax/WiBro modules
Solid State Drives/Memory
Wireless LAN cards
Typical Application
HyperLight Load is a registered 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
February 5, 2015
Revision 2.1
Micrel, Inc.
MIC23150
Ordering Information
Marking
(1)
Code
Nominal Output
(2)
Voltage
Junction
Temperature Range
MIC23150-CYMT
QKC
1.0V
−40°C to +125°C
8-Pin 2mm × 2mm TDFN
Pb-Free
MIC23150-4YMT
QK4
1.2V
−40°C to +125°C
8-Pin 2mm × 2mm TDFN
Pb-Free
MIC23150-55YMT
QKZ
1.35V
−40°C to +125°C
8-Pin 2mm × 2mm TDFN
Pb-Free
MIC23150-GYMT
QKG
1.8V
−40°C to +125°C
8-Pin 2mm × 2mm TDFN
Pb-Free
MIC23150-SYMT
QKS
3.3V
−40°C to +125°C
8-Pin 2mm × 2mm TDFN
Pb-Free
Part Number
Package
(3)
Lead
Finish
Notes:
1. ▲= Pin 1 identifier.
2. Other voltages are available. Contact Micrel for details.
3. GREEN, RoHS-compliant package. Lead finish is NiPdAu. Mold compound is Halogen-Free.
Pin Configuration
8-Pin 2mm × 2mm Thin DFN (MM)
(Top View)
Pin Description
Pin Number
Pin Name
1, 2
SW
Switch (Output): Internal power MOSFET output switches.
3
EN
Enable (Input): Logic high enables operation of the regulator. Logic low will shut down the device. Do
not leave floating.
4
SNS
5
AGND
6, 7
VIN
8
PGND
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Pin Function
Sense: Connect to VOUT as close to output capacitor as possible to sense output voltage.
Analog Ground: Connect to central ground point where all high current paths meet (CIN, COUT, and
PGND) for best operation.
Input Voltage: Connect a capacitor-to-ground to decouple the noise.
Power Ground.
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Micrel, Inc.
MIC23150
Absolute Maximum Ratings(4)
Operating Ratings(5)
Supply Voltage (VIN) . ……………………………………….6V
Sense (VSNS).. ..................................................................6V
Output Switch Voltage (VSW) ............................................ 6V
Enable Input Voltage (VEN) .. ..............................−0.3V to VIN
Storage Temperature Range .. ……………−65°C to +150°C
(6)
ESD Rating .................................................................. 2kV
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
8-pin 2mm × 2mm Thin DFN (θJA) ..................... 90°C/W
Electrical Characteristics(7)
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.
2.7
Supply Voltage Range
Undervoltage
Lockout Threshold
2.45
(Turn-on)
Undervoltage
Lockout Hysteresis
2.55
Max.
Units
5.5
V
2.65
V
75
Quiescent Current
IOUT = 0mA , SNS > 1.2 × VOUTNOM
Shutdown Current
VEN = 0V; VIN = 5.5V
Output Voltage Accuracy
Typ.
VIN = 3.6V if VOUTNOM < 2.5V, ILOAD = 20mA
VIN = 4.5V if VOUTNOM ≥ 2.5V, ILOAD = 20mA
SNS = 0.9 × VOUTNOM
Output Voltage
Line Regulation
VIN = 3.6V to 5.5V if VOUTNOM < 2.5V, ILOAD = 20mA
Output Voltage
Load Regulation
20mA < ILOAD < 500mA, VIN = 3.6V if VOUTNOM < 2.5V
PWM Switch
ON-Resistance
ISW = 100mA PMOS
Switching Frequency
IOUT = 120mA
Soft-Start Time
VOUT = 90%
Enable Threshold
Turn-on
23
40
µA
0.01
5
µA
+2.5
%
−2.5
2.2
Current Limit
VIN = 4.5V to 5.5V if VOUTNOM ≥ 2.5V, ILOAD = 20mA
20mA < ILOAD < 500mA, VIN = 5.0V if VOUTNOM ≥ 2.5V
ISW = −100mA NMOS
0.5
mV
3.4
A
0.3
%/V
0.75
%/A
0.150
0.110
Ω
4
MHz
115
µs
0.8
1.2
V
Enable Input Current
0.1
2
µA
Overtemperature Shutdown
160
°C
Overtemperature
Shutdown Hysteresis
20
°C
Notes:
4. Exceeding the absolute maximum ratings may damage the device.
5. The device is not guaranteed to function outside its operating ratings.
6. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
7. Specification for packaged product only
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MIC23150
Typical Characteristics
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MIC23150
Typical Characteristics (Continued)
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MIC23150
Functional Characteristics
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MIC23150
Functional Characteristics (Continued)
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MIC23150
Functional Characteristics (Continued)
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MIC23150
Functional Characteristics (Continued)
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MIC23150
Functional Diagram
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MIC23150
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 PCB Layout Recommendations for
details.
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. MIC23150 features built-in soft-start circuitry that
reduces in-rush current and prevents the output voltage
from overshooting at start up. Do not leave the EN pin
floating.
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.
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 PCB Layout Recommendations for
more details.
AGND
The analog ground (AGND) is the ground path
biasing and control circuitry. The current loop
signal ground should be separate from the power
(PGND)
loop.
Refer
to
the
PCB
Recommendations for more details.
for the
for the
ground
Layout
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 PCB Layout Recommendations for more details.
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MIC23150
Application Information
The MIC23150 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 2mm × 2mm Thin
DFN package, the IC requires only three external
components while meeting today’s miniature portable
electronic device needs. Using the HyperLight Load
switching scheme, the MIC23150 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.
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 in Equation
1:
Input Capacitor
A 2.2µF ceramic capacitor or greater should be placed
close to the VIN pin and PGND pin for bypassing. A TDK
C1608X5R0J475K, 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.
1 − VOUT / VIN
IPEAK = IOUT + VOUT
2× f ×L
As shown in Equation 1, 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.
Output Capacitor
The MIC23150 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 TDK C1608X5R0J475K,
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 size of the inductor depends on the requirements of
the application. Refer to the Typical Application
Schematic and Bill of Materials sections 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” sub-section.
Compensation
The MIC23150 is designed to be stable with a 0.47µH to
2.2µH inductor with a minimum of 2.2µF ceramic (X5R)
output capacitor.
Duty Cycle
The typical maximum duty cycle of the MIC23150 is 80%.
Inductor Selection
When selecting an inductor, it is important to consider the
following factors (not necessarily in the order of
importance):
•
•
•
•
Eq. 1
Efficiency Considerations
Efficiency is defined as the amount of useful output
power, divided by the amount of power supplied.
Inductance
Rated current value
Size requirements
DC resistance (DCR)
V
×I
Efficiency% = OUT OUT
V ×I
IN IN
× 100
Eq. 2
The MIC23150 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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MIC23150
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.
The DCR losses can be calculated as shown in Equation
3:
There are two types of losses in switching converters; DC
losses and switching losses. DC losses are simply the
2
power dissipation of I R. Power is dissipated in the highside 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 driving
the gates on and off at a constant 4MHz frequency and
the switching transitions make up the switching losses.
From that, the loss in efficiency due to inductor resistance
can be calculated as in Equation 4:
PDCR = IOUT 2 × DCR
VOUT × IOUT
Efficiency Loss = 1 −
VOUT × IOUT + PDCR
× 100 Eq. 4
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.
Figure 1 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 MIC23150 is able to
maintain high efficiency at low output currents.
HyperLight Load Mode
MIC23150 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-ontime. This increases the output voltage. If the output
voltage is over the regulation threshold, then the error
comparator turns the PMOS off for a minimum-off-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 MIC23150 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 MIC23150 during light
load currents by only switching when it is needed. As the
load current increases, the MIC23150 goes into
continuous conduction mode (CCM) and switches at a
frequency centered at 4MHz. The equation to calculate
the load when the MIC23150 goes into continuous
conduction mode may be approximated by Equation 5:
Figure 1. Efficiency Under Load
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.
February 5, 2015
Eq. 3
(V − VOUT ) × D
ILOAD > IN
2L × f
13
Eq. 5
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Micrel, Inc.
MIC23150
As shown in Equation 5, the load at which MIC23150
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 2, as the output current increases, the
switching frequency also increases until the MIC23150
goes from HyperLight Load mode to PWM mode at
approximately 120mA. The MIC23150 will switch at a
relatively constant frequency around 4MHz once the
output current is over 120mA.
Figure 2. SW Frequency vs. Output Current
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MIC23150
Typical Application Schematic
Bill of Materials
Item
C1, C2
L1
Part Number
C1608X5R0J475K
(8)
TDK
VLS3010T-1R0N1R9
TDK
VLS4012T-1R0N1R6
TDK
DO2010-102ML
U1
Manufacturer
MIC23150-xYMT
Coilcraft
Description
4.7µF Ceramic Capacitor, 6.3V, X5R, Size 0603
Qty.
2
1µH, 1.9A, 60mΩ, L3.0mm × W3.0mm × H1.0mm
1µH, 2.8A, 50mΩ, L4.0mm × W4.0mm × H1.2mm
(9)
(10)
Micrel, Inc.
1
1µH, 1.8A, 162mΩ, L2.0mm × W2.0mm × H1.0mm
4MHz 2A Buck Regulator with HyperLight Load Mode
1
Notes:
8. TDK: www.tdk.com.
9. Coilcraft: www.coilcraft.com.
10. Micrel, Inc.: www.micrel.com.
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MIC23150
PCB Layout Recommendations
Top Layer
Bottom Layer
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MIC23150
Package Information and Recommended Landing Pattern(11)
8-Pin 2mm × 2mm TDFN (MM)
Note:
11. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com.
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MIC23150
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, Inc. is a leading global manufacturer of IC solutions for the worldwide high performance linear and power, LAN, and timing & communications
markets. The Company’s products include advanced mixed-signal, analog & power semiconductors; high-performance communication, clock
management, MEMs-based clock oscillators & crystal-less clock generators, Ethernet switches, and physical layer transceiver ICs. Company
customers include leading manufacturers of enterprise, consumer, industrial, mobile, telecommunications, automotive, and computer products.
Corporation headquarters and state-of-the-art wafer fabrication facilities are located in San Jose, CA, with regional sales and support offices and
advanced technology design centers situated throughout the Americas, Europe, and Asia. Additionally, the Company maintains an extensive network
of distributors and reps worldwide.
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this datasheet. 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.
© 2008 Micrel, Incorporated.
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