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