MIC23051_09 Datasheet, PDF (1/13 Pages) Micrel Semiconductor – 4MHz PWM Buck Regulator with HyperLight Load and Voltage Scaling

MIC23051
4MHz PWM Buck Regulator with
HyperLight Load™ and Voltage Scaling
General Description
Features
The Micrel MIC23051 is a high efficiency 600mA PWM
synchronous buck (step-down) regulator featuring
HyperLight Load™, a patented switching scheme that
offers best in class light load efficiency and transient
performance while providing very small external
components and low output ripple at all loads.
• Input voltage: 2.7V to 5.5V
HyperLight Load™
• 600mA output current
• Fixed output voltage from 0.72V to 3.3V
• Output voltage scaling option
• Ultra fast transient response
The MIC23051 has an output voltage scaling feature that
can toggles between two different voltage levels.
The MIC23051 also has a very low typical quiescent
current draw of 20µA and can achieve over 85% efficiency
even at 1mA. The device allows operation with a tiny
inductor ranging from 0.47µH to 2.2µH and uses a small
output capacitor that enables a sub-1mm height solution.
In contrast to traditional light load schemes HyperLight
Load™ architecture does not need to trade off control
speed to obtain low standby currents and in doing so the
device only needs a small output capacitor to absorb the
load transient as the powered device goes from light load
to full load.
• 20µA typical quiescent current
• 4MHz in CCM PWM operation in normal mode
• 0.47µH to 2.2µH inductor
• Low voltage output ripple
– 25mVpp in HyperLight Load mode
– 3mV output voltage ripple in full PWM mode
• >93% efficiency
• ~85% at 1mA
• Micropower shutdown
• Available in 8-pin 2mm x 2mm MLF^®
• –40°C to +125°C junction temperature range
At higher loads the MIC23051 provides a constant
switching frequency of greater than 4MHz while providing
peak efficiencies greater than 93%.
The MIC23051 is available in fixed output voltage options
from 0.72V to 3.3V eliminating external feedback
components. The MIC23051 is available in an 8-pin 2mm x
2mm MLF^® with a junction operating range from –40°C to
+125°C.
Applications
• Cellular phones
• Digital cameras
• Portable media players
• Wireless LAN cards
• WiFi/WiMax/WiBro modules
Data sheets and support documentation can be found on • USB Powered Devices
Micrel’s web site at: www.micrel.com.
____________________________________________________________________________________________________________
Typical Application
Efficiency VOUT = 1.8V
100
90
VIN = 2.7V
80
VIN = 3.6V
VIN = 3.3V
70
60
VOUT = 1.8V
L = 1µH
50
1
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
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
July 2009
M9999-070809-F