MIC2179YSM-TR

The Micrel MIC2179 is a 200kHz synchronous buck (step-down) switching regulator designed for high-efficiency, battery-powered applications.

The MIC2179 operates from a 4.5V to 16.5V input and features internal power MOSFETs that can supply up to 1.5A 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 MIC2179 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 MIC2179 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.

The MIC2179 and is packaged in a 20-lead SSOP package with an operating temperature range of -40°C to +85°C.

Key Features

• 4.5V to 16.5V input voltage range
• Dual-mode operation for high efficiency (up to 96%)
• PWM mode for > 150mA load current
• Skip mode for <150mA load current
• 150mΩ 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