General Description
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.

Features
• 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