MICROCHIP MIC2178-5.0YWM

The MIC2178 is a 200kHz synchronous buck (step-down) 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. The MIC2178 achieves high efficiency over a wide output current range by operating in either PWM or skip mode. The operating mode is externally selected, typically by an intelligent system, which chooses the appropriate mode according to operating conditions, efficiency, and noise requirements. The switching frequency is preset to 200kHz and can be synchronized to an external clock signal of up to 300kHz. The MIC2178 uses current-mode control with internal current sensing. Current-mode control provides superior line regulation and makes the regulator control loop easy to compensate. The output is protected with pulse-by-pulse current limiting and thermal shutdown. Undervoltage lockout turns the output off when the input voltage is less than 4.5V.

• Input Voltage Range: +4.5V to +16.5V
• Dual-Mode Operation for High Efficiency (up to 96%):
  • PWM Mode for >200 mA Load Current
  • Skip Mode for <200 mA Load Current
• 100 mΩ Internal Power MOSFETs at 12V Input
• 200 kHz Preset Switching Frequency
• Low Quiescent Current:
  • 1.0 mA in PWM Mode
  • 600 μA in Skip Mode
  • <5 μA 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

• High-Efficiency, Battery-Powered Supplies
• Buck (Step-Down) DC/DC Converters
• Palmtop Computers
• Laptop Computers
• Cellular Telephones
• Handheld Instruments
• Battery Chargers