MIC23250_10 Datasheet, PDF (1/20 Pages) Micrel Semiconductor – 4MHz Dual 400mA Synchronous Buck Regulator with HyperLight Load

MIC23250
4MHz Dual 400mA Synchronous Buck
Regulator with HyperLight Load™
General Description
Features
The MIC23250 is a high efficiency 4MHz dual 400mA
synchronous buck regulator with HyperLight Load™ mode.
HyperLight Load™ provides very high efficiency at light
loads and ultra-fast 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 fixed output MIC23250 has
a tiny 2mm x 2mm Thin MLF^® package that saves
precious board space by requiring only 6 additional
external components to drive both outputs up to 400mA
each.
The device is designed for use with a 1µH inductor and a
4.7µF output capacitor that enables a sub-1mm height.
The MIC23250 has a very low quiescent current of 33µA
with both outputs enabled and can achieve over 85%
efficiency at 1mA. At higher loads the MIC23250 provides a
constant switching frequency around 4MHz while providing
peak efficiencies up to 94%.
The MIC23250 fixed output voltage option is available in a
10-pin 2mm x 2mm Thin MLF^®. The adjustable output
options is available in a 12-pin 2.5mm x 2.5mm Thin MLF^®.
The MIC23250 is designed to operate over the junction
operating range from –40°C to +125°C.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
• Input voltage: 2.7V to 5.5V
HyperLight Load™
• Dual output current 400mA/400mA
• Up to 94% peak efficiency and 85% efficiency at 1mA
• 33µA dual quiescent current
• 1µH inductor with a 4.7µF capacitor
• 4MHz in PWM operation
• Ultra fast transient response
• Low voltage output ripple
• 20mVpp in HyperLight Load™ mode
• 3mV output voltage ripple in full PWM mode
• 0.01µA shutdown current
• Fixed output:10-pin 2mm x 2mm Thin MLF®
• Adjustable output:12-pin 2.5mm x 2.5mm Thin MLF®
• –40°C to +125°C junction temperature range
Applications
• Mobile handsets
• Portable media players
• Portable navigation devices (GPS)
• WiFi/WiMax/WiBro modules
• Digital cameras
• Wireless LAN cards
• USB Powered Devices
____________________________________________________________________________________________________________
Typical Application
Efficiency V _OUT = 1.8V
100
90 ^{VIN = 2.7V VIN = 3.0V}
80
70 VIN = 4.2V
VIN = 3.6V
60
50
40
30
20
10
011
L = 1µH
C_OUT = 4.7µF
0
100
1000
OUTPUT CURRENT (mA)
HyperLight Load is a trademark of Micrel, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
June 2010
M9999-061110-E