General Description
The Micrel MIC2178 is a 200kHz synchronous buck (stepdown) switching regulator designed for high-efficiency, battery-powered applications.
The MIC2178 operates from a 4.5V to 16.5V input and features internal power MOSFETs that can supply up to 2.5A output current. It can operate with a maximum duty cycle of 100% for use in low-dropout conditions. It also features a shutdown mode that reduces quiescent current to less than 5µA.

Features
• 4.5V to 16.5V input voltage range
• Dual-mode operation for high efficiency (up to 96%)
    PWM mode for > 200mA load current
    Skip mode for < 200mA load current
• 100mΩ internal power MOSFETs at 12V input
• 200kHz preset switching frequency
• Low quiescent current
    1.0mA in PWM mode
    600µA in skip mode
    < 5µA in shutdown mode
• Current-mode control
    Simplified loop compensation
    Superior line regulation
• 100% duty cycle for low dropout operation
• Current limit
• Thermal shutdown
• Undervoltage lockout

Applications
• High-efficiency, battery-powered supplies
• Buck (step-down) dc-to-dc converters
• Palmtop computers
• Laptop computers
• Cellular telephones
• Hand-held instruments
• Battery Chargers