MIC2202
High Efficiency 2MHz Synchronous Buck
Converter 1µF Stable PWM Regulator
General Description
The Micrel MIC2202 is a high efficiency 2MHz PWM
synchronous buck regulator. The fast 2MHz operation
along with a proprietary compensation scheme allows the
smallest possible external components. The MIC2202 can
operate with a 1µF ceramic output capacitor and a small,
low DC-resistance, 2.2µH inductor, reducing system size
and cost while allowing a high level of efficiency.
The MIC2202 operates from 2.3V to 5.5V input and
features internal power MOSFETs that can supply over
600mA of output current with output voltages down to
0.5V. The MIC2202 implements a constant 2MHz pulse-
width-modu-lation (PWM) control scheme which reduces
noise in sensitive RF, audio, and communications
applications. Additionally, the MIC2202 can be
synchronized to an external clock, or multiple MIC2202s
can easily be daisy-chained with the SYNCLOCK feature.
The MIC2202 has a high bandwidth loop (up to 500kHz)
which allows ultra fast transient response times. This is
very useful when powering applications that require fast
dynamic response such as CPU cores and RF circuitry in
high performance cellular phones and PDAs. The
MIC2202 is available in 10-pin MSOP and 10-pin 3mm ×
3mm MLF
®
package options with an operating junction
temperature range from –40°C to +125°C.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
Input voltage range: 2.3V to 5.5V
Output down to 0.5V/600mA
2MHz PWM operation
Stable with 1µF ceramic output capacitor.
Ultra-fast transient response (up to 500kHz GBW)
Internal compensation
All ceramic capacitors
>95% efficiency
Fully integrated MOSFET switches
Easily synchronized to external clock
SYNCLOCK feature to daisy chain multiple 2202s
Requires only 4 external components
1% line and load regulation
Logic controlled micropower shutdown
Thermal shutdown and current limit protection
10-pin MSOP and 10-pin 3mm×3mm MLF
®
package
options
•
–40°C to +125°C junction temperature range
•
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•
•
•
•
•
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Applications
•
•
•
•
•
Cellular phones
PDAs
802.11 WLAN power supplies
FPGA/ASIC power supplies
Dynamically adjustable power supply for CDMA/W-
CDMA RF power amps
•
DSL modems
•
Tape drives
___________________________________________________________________________________________________________
Typical Application
2.2µH
V
OUT
3.3V
600mA
10
9
8
7
6
1.78k
10nF
10k
1µF
100
95
EFFICIENCY (%)
90
85
80
75
70
65
Efficiency 3.3V
OUT
4.2V
IN
5V
IN
V
IN
2.3V to 5.5V
SYNC_IN
SYNC_OUT
EN
1
2
3
4
5
L = 2.2µH
C
OUT
= 1µF
Adjustable Output Synchronous Buck Regulator
60
0
0.1 0.2 0.3 0.4 0.5
OUTPUT CURRENT (A)
0.6
MLF and
MicroLeadFrame
are registered trademarks of 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
March 2007
1
M9999-031907
Micrel, Inc.
MIC2202
Ordering Information
Part Number
MIC2202BMM
MIC2202BML
MIC2202YMM
MIC2202YML
Voltage
Adj.
Adj.
Adj.
Adj.
Temperature Range
–40° to +125°C
–40° to +125°C
–40° to +125°C
–40° to +125°C
Package
10-Pin MSOP
10-Pin MLF
®
10-Pin MSOP
10-Pin MLF
®
Lead Finish
Standard
Standard
Pb-Free
Pb-Free
Pin Configuration
SW 1
VIN 2
SYNC_IN 3
SYNC_OUT 4
EN 5
10 GND
9 GND
8 GND
7 BIAS
6 FB
10-Pin MSOP (MM)
10-Pin MLF
®
(ML)
SW 1
VIN 2
SYNC_IN 3
SYNC_OUT 4
EN 5
EP
10 GND
9 GND
8 GND
7 BIAS
6 FB
Pin Description
Pin Number
1
2
3
4
5
6
7
8, 9, 10
EP
Pin Name
SW
VIN
SYNC_IN
SYNC_OUT
EN
FB
BIAS
GND
GND
Pin Function
Switch (Output): Internal power MOSFET output switches.
Supply Voltage (Input): Requires bypass capacitor to GND.
SYNC_IN for the MIC2202: Sync the main switching frequency to an external
clock.
SYNC_OUT an open collector output.
A low level EN will power down the device, reducing the quiescent current to
under 1µA.
Input to the error amplifier, connect to the external resistor divider network to set
the output voltage.
Internal circuit bias supply, nominally 2.3V. Must be de-coupled to signal ground
with a 0.01µF capacitor.
Ground.
Ground, backside pad.
March 2007
2
M9999-031907
Micrel, Inc.
MIC2202
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) .........................................................6V
Output Switch Voltage (V
SW
) ............................................6V
Logic Input Voltage (V
EN
, V
SYNC_IN
).................... V
IN
to –0.3V
Power Dissipation .....................................................
Note 3
Storage Temperature (T
s
) .........................–65°C to +150°C
ESD Rating
(4)
.................................................................. 2kV
Operating Ratings
(2)
Supply Voltage (V
IN
)..................................... +2.3V to +5.5V
Junction Temperature (T
J
) ..................–40°C
≤
T
J
≤
+125°C
Package Thermal Resistance
MSOP-10L (θ
JA
) ...............................................115°C/W
3x3 MLF-10 (θ
JA
) ...............................................60°C/W
Electrical Characteristics
(5)
T
A
= 25°C with V
IN
= 3.5V unless otherwise noted;
bold
values indicate –40°C< T
J
< +125°C.
Parameter
Supply Voltage Range
Quiescent Current
MIC2202 [Adjustable] Feedback
Voltage
Output Voltage Line Regulation
Output Voltage Load Regulation
Bias Regulator Output Voltage
Maximum Duty Cycle
Current Limit
Switch ON-Resistance
Enable Input Current
Sync Frequency Range
SYNC_IN Threshold
Sync Minimum Pulse Width
SYNC_IN Input Current
Oscillator Frequency
Enable Threshold
Enable Hysteresis
Over-temperature Shutdown
Over-temperature Shutdown
Hysteresis
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Absolute maximum power dissipation is limited by maximum junction temperature where P
D(MAX)
= (T
J(MAX)
– T
A
) ÷
θ
JA
.
4. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
5. Specification for packaged product only.
Condition
EN = V
IN
; V
FB
= 0.55V (not switching)
EN = 0V
Min
2.3
Typ
350
0.01
Max
5.5
450
1
0.5125
0.5
0.5
2.6
2.5
0.9
0.75
1
2.5
1.7
1
Units
V
µA
µA
V
%
%
V
%
A
Ω
Ω
µA
MHz
V
ns
µA
MHz
V
mV
°C
°C
0.4875
V
OUT
< 2V; V
IN
= 2.3V to 5.5V, I
LOAD
= 100mA
0mA < I
LOAD
< 500mA
2.2
V
FB
= 0.7V
V
FB
= 0.7V
V
IN
= 3.5V, I
SW
= 300mA; V
FB
= 0.35V
V
IN
= 3.5V, I
SW
= 300mA; V
FB
= 0.55V
1.6
0.7
100
1
0.5
0.05
0.1
2.32
1.8
0.65
0.55
0.01
1
10
1.8
0.5
2
0.9
20
160
20
2.2
1.3
March 2007
3
M9999-031907
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