MIC4744 Datasheet, PDF (1/23 Pages) Micrel Semiconductor – 4 MHz Dual 2A Integrated Switch Buck Regulator

MIC4744
4 MHz Dual 2A Integrated Switch
Buck Regulator
General Description
The Micrel MIC4744 is a high efficiency dual PWM buck
(step-down) regulator that provides dual 2A current output.
The MIC4744 operates at 4MHz. A proprietary internal
compensation technique allows a closed loop bandwidth of
over 200kHz.
The low on-resistance internal P-Channel MOSFET of the
MIC4744 allows efficiencies over 90%, reduces external
components count and eliminates the need for an
expensive current sense resistor.
The MIC4744 operates from 2.9V to 5.5V input and the
output can be adjusted down to 0.6V. The device can
operate with a maximum duty cycle of 100% for use in low-
dropout conditions.
The MIC4744 is available in the exposed pad 16-pin
3mm x 3mm MLF^® and ETSSOP-16 packages with
junction operating temperature ranging from –40°C to
+125°C.
All support documentation can be found on Micrel’s web
site at: www.micrel.com.
Features
• 2.9 to 5.5V supply voltage
• 4MHz PWM mode
• 2A Dual output
• Greater than 90% efficiency
• 100% maximum duty cycle
• Output voltage adjustable down to 0.6V
• Ultra-fast transient response
• Ultra-small external components
Stable with a 0.47µH inductor and a 10µF output
capacitor
• Fully integrated 2A MOSFET switches
• Micro-power shutdown
• Thermal shutdown and current limit protection
• Available in 3mm x 3mm 16-pin MLF^® and 16-pin
TSSOP packages
• –40°C to +125°C junction temperature range
Applications
• Broadband: xDSL modems
• Automotive satellite radios
• HD STB, DVD/TV recorder
• Computer peripherals: printers and graphic cards
• FPGA/ASIC
• General point of load
Typical Application
2A 4MHz Dual Buck Regulator
5.0Vin 3.3Vout Efficiency
100
98
96
94
92
90
88
86
84
82
80
0.0
0.4
0.8
1.2
1.6
2.0
OUTPUT CURRENT (A)
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
March 2009
1
M9999-030209-C