MIC23051
4MHz PWM Buck Regulator with
HyperLight Load™ and Voltage Scaling
General Description
Features
The Micrel MIC23051 is a high efficiency 600mA PWM
HyperLight Load™
•
Input voltage: 2.7V to 5.5V
synchronous buck (step-down) regulator featuring
•
600mA output current
HyperLight Load™, a patented switching scheme that
•
Fixed output voltage from 0.72V to 3.3V
offers best in class light load efficiency and transient
•
Output voltage scaling option
performance while providing very small external
•
Ultra fast transient response
components and low output ripple at all loads.
•
20µA typical quiescent current
The MIC23051 has an output voltage scaling feature that
can toggles between two different voltage levels.
•
4MHz in CCM PWM operation in normal mode
The MIC23051 also has a very low typical quiescent
•
0.47µH to 2.2µH inductor
current draw of 20µA and can achieve over 85% efficiency
•
Low voltage output ripple
even at 1mA. The device allows operation with a tiny
– 25mVpp in HyperLight Load mode
inductor ranging from 0.47µH to 2.2µH and uses a small
– 3mV output voltage ripple in full PWM mode
output capacitor that enables a sub-1mm height solution.
•
>93% efficiency
In contrast to traditional light load schemes HyperLight
•
~85% at 1mA
Load™ architecture does not need to trade off control
speed to obtain low standby currents and in doing so the
•
Micropower shutdown
device only needs a small output capacitor to absorb the
•
Available in 8-pin 2mm x 2mm MLF
®
load transient as the powered device goes from light load
•
–40°C to +125°C junction temperature range
to full load.
At higher loads the MIC23051 provides a constant
Applications
switching frequency of greater than 4MHz while providing
peak efficiencies greater than 93%.
•
Cellular phones
The MIC23051
is available in fixed output voltage options
•
Digital cameras
from 0.72V to 3.3V eliminating external feedback
•
Portable media players
components.
The MIC23051 is available in an 8-pin 2mm x
•
Wireless LAN cards
2mm MLF
®
with a junction operating range from –40°C to
•
WiFi/WiMax/WiBro modules
+125°C.
•
USB Powered Devices
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
____________________________________________________________________________________________________________
Typical Application
Efficiency V
OUT
= 1.8V
100
90
80
V
IN
= 3.3V
70
60
50
1
V
IN
= 2.7V
V
IN
= 3.6V
V
OUT
= 1.8V
L = 1µH
10
100
1000
OUTPUT CURRENT (mA)
HyperLight Load is a trademark of Micrel, Inc.
MLF and
MicroLeadFrame
are registered trademarks of Amkor Technology, Inc.
Protected by US Patent No. 7064531
M9999-111908-E
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
November 2008
Micrel, Inc.
MIC23051
Ordering Information
Part Number
Marking
Voltage
Scaled to
with VSC low
1.0V
1.0V
1.15V
0.95V
Nominal
Output
Voltage
1.8V
1.2V
1.40V
1.25V
Junction
Temp. Range
–40° to +125°C
–40° to +125°C
–40° to +125°C
–40° to +125°C
Package
Lead Finish
MIC23051-CGYML
MIC23051-C4YML
MIC23051-16YML
MIC23051-945YML
Note
1.
2.
JCG
JC4
J16
945
8-Pin 2x2 MLF
®
8-Pin 2x2 MLF
®
8-Pin 2x2 MLF
8-Pin 2x2 MLF
®
®
Pb-Free
Pb-Free
Pb-Free
Pb-Free
Other output voltage combinations (0.72 to 3.3V) available, contact Micrel Marketing for details.
MLF is a GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
®
Pin Configuration
SW
EN
VSC
SNS
1
2
3
4
8
7
6
5
PGND
VIN
AGND
CFF
8-Pin 2mm x 2mm MLF
®
(Top View)
Pin Description
Pin Number
1
2
3
4
5
6
7
8
Pin Name
SW
EN
VSC
SNS
CFF
AGND
VIN
PGND
Pin Name
Switch (Output): Internal power MOSFET output switches.
Enable (Input). Logic low will shut down the device, reducing the quiescent
current to less than 4µA. Do not leave floating.
Voltage scaling pin (input): A low on this pin will scale the output voltage
down to specified level. Do not leave floating.
Connect to V
OUT
to sense output voltage.
Feed Forward Capacitor. Connect a 560pF capacitor.
Analog Ground.
Supply Voltage (Input): Requires bypass capacitor to GND.
Power Ground.
November 2008
2
M9999-111908-E
Micrel, Inc.
MIC23051
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) .........................................................6V
Output Switch Voltage (V
SW
) ............................................6V
Output Switch Current (I
SW
)..............................................2A
Logic Input Voltage (V
EN
, V
LQ
)........................... V
IN
to –0.3V
Storage Temperature Range (T
s
)..............–65°C to +150°C
ESD Rating
(3)
.................................................................. 3kV
Operating Ratings
(2)
Supply Voltage (V
IN
)......................................... 2.7V to 5.5V
Logic Input Voltage (V
EN)
....................................-0.3V to V
IN
Junction Temperature (T
J
) ..................–40°C
≤
T
J
≤
+125°C
Thermal Resistance
2x2 MLF-8 (θ
JA
) .................................................90°C/W
Electrical Characteristics
(4)
T
A
= 25°C with V
IN
= V
EN
= V
SC
= 3.6V; L = 1µH; C
FF
= 560pF; C
OUT
= 4.7µF; I
OUT
= 20mA unless otherwise specified.
Bold
values indicate –40°C< T
J
< +125°C. Important design targets are in
italics.
Parameter
Supply Voltage Range
Under-Voltage Lockout Threshold
UVLO Hysteresis
Quiescent Current,
Hyper LL mode
Shutdown Current
Output Voltage Accuracy
VSC Low, V
IN
= 3.0V, I
LOAD
= 20mA
SNS pin input current
Current Limit in PWM Mode
Output Voltage Line Regulation
Output Voltage Load Regulation
Output Voltage Line Regulation
Output Voltage Load Regulation
Maximum Duty Cycle
PWM Switch ON-Resistance**
See Design Note
Frequency
SoftStart Time
VSC threshold voltage
VSC hysteresis
Output transition time
Enable Threshold
Enable Hysteresis
Enable Input Current
Over-temperature Shutdown
Over-temperature Shutdown
Hysteresis
V
OUT
= 1V
SNS = 0.9*V
NOM
V
IN
= 3.0V to 5.5V, I
LOAD
= 20mA, V
SC
= 3.6V
20mA < I
LOAD
< 500mA, V
SC
= 3.6V
V
IN
= 3.0V to 5.5V, I
LOAD
= 20mA, V
SC
= 0V
20mA < I
LOAD
< 500mA, V
SC
= 0V
SNS
≤
V
NOM,
V
OUT
= 1.8V
I
SW
= 100mA PMOS
I
SW
= -100mA NMOS
V
SC
= 3.6V, I
LOAD
= 120mA
V
SC
= 0V, I
LOAD
= 120mA
V
OUT
= 90%
-2.5
1
1
0.5
0.3
0.5
0.3
89
0.45
0.5
4
4
650
20
800
800
0.5
35
0.1
165
20
1.2
2
V
mV
µA
°C
°C
+2.5
Condition
(turn-on)
Min
2.7
2.45
2.55
100
20
0.01
-2.5
Typ
Max
5.5
2.65
Units
V
V
mV
µA
µA
%
%
%
%
µA
A
%
%
%
%
%
Ω
Ω
MHz
MHz
µs
V
mV
µs
I
OUT
= 0mA , SNS > 1.8V
V
IN
= 5.5V; V
EN
= 0V;
VSC High, V
IN
= 3.0V, I
LOAD
= 20mA
35
4
+2.5
0.65
1.7
80
3.4
3.4
0.5
4.6
4.6
1.2
VSC from low to high
VSC from high to low
(turn-on)
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.
November 2008
3
M9999-111908-E
微控制器 MCU
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