MIC23254 Datasheet, PDF (1/17 Pages) Micrel Semiconductor – 4MHz Dual 400mA Synchronous Buck Regulator with Low Input Voltage and HyperLight Load™

MIC23254
4MHz Dual 400mA Synchronous Buck
Regulator with Low Input Voltage and
HyperLight Load™
General Description
Features
The MIC23254 is a low-input voltage, 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. MIC23254 operates from an input voltage
down to 2.5V for low battery states. The MIC23254 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.
• Low input voltage range: 2.5V to 5.5V
• 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®
• –40°C to +125°C junction temperature range
The MIC23254 has a very-low quiescent current of 33µA
with both outputs enabled and can achieve over 85%
efficiency at 1mA. At higher loads the MIC23254 provides a
constant switching frequency around 4MHz while providing
peak efficiencies over 90%.
The MIC23254 fixed output voltage option is available in a
10-pin 2mm x 2mm Thin MLF^®. The MIC23254 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.
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
VOUT = 1.8V
100
90
VIN = 3.0V
80
70
60
VIN = 2.7V
VIN = 3.6V
50
40
VIN = 4.2V
30
20
10
0
1
L = 1µH
COUT = 4.7µF
10
100
1000
LOAD (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
May 2010
M9999-052510