MIC22405 Datasheet, PDF (1/30 Pages) Micrel Semiconductor – 4A Integrated Switch High-Efficiency Synchronous Buck Regulator

MIC22405
4A Integrated Switch High-Efficiency
Synchronous Buck Regulator with
Frequency Programmable upto 4MHz
General Description
Features
The Micrel MIC22405 is a high efficiency, 4A integrated
switch synchronous buck (step-down) regulator. The
MIC22405 is optimized for highest efficiency, achieving
more than 95% efficiency while still switching at 1MHz.
The ultra-high speed control loop keeps the output voltage
within regulation even under the extreme transient load
swings commonly found in FPGAs and low-voltage ASICs.
The output voltage is pre-bias safe and can be adjusted
down to 0.7V to address all low-voltage power needs.
The MIC22405 offers a full range of sequencing and
tracking options. The Enable/Delay (EN/DLY) pin,
combined with the Power Good (PG) pin, allows multiple
outputs to be sequenced in any way during turn-on and
turn-off. The Ramp Control™ (RC) pin allows the device to
be connected to another product in the MIC22xxx and/or
MIC68xxx family, to keep the output voltages within a
certain ∆V on start-up.
The MIC22405 is available in a 20-pin 3mm x 4mm MLF^®
with a 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 range: 2.9V to 5.5V
• Output voltage adjustable down to 0.7V
• Output load current up to 4A
• Safe start-up into a pre-biased output
• Full sequencing and tracking capability
• Power Good output
• Efficiency > 95% across a broad load range
• Programmable frequency 300kHz to 4MHz
• Ultra-fast transient response
• Easy RC compensation
• 100% maximum duty cycle
• Fully-integrated MOSFET switches
• Thermal shutdown and current-limit protection
• 20-pin 3mm x 4mm MLF^®
• –40°C to +125°C junction temperature range
Applications
• High power density point-of-load conversion
• Servers, routers, and base stations
• DVD recorders / Blu-ray players
• Computing peripherals
• FPGAs, DSP and low voltage ASIC power
_________________________________________________________________________________________________________________________
Typical Application
MIC22405 4A 1MHz Synchronous Output Converter
100
95
90
85
80
75
70
0
Efficiency (VIN = 5.0V)
vs. Output Current
3.3V
1.8V
VIN = 5.0V
1
2
3
4
OUTPUT CURRENT (A)
Ramp Control 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 2011
M9999-061511-A