MICROCHIP MCP1603T-250I/OS

The MCP1603/B/L is a high-efficiency, fully-integrated 500 mA synchronous buck regulator whose 2.7V to 5.5V input voltage range makes it ideally suited for applications powered from 1-cell Li-Ion or 2-cell/3-cell NiMH/NiCd batteries.

At heavy loads, the MCP1603/B/L operates in the 2.0 MHz fixed frequency pulse-width modulation (PWM) mode, which provides a low noise, low-output ripple, small-size solution. When the load is reduced to light levels, the MCP1603/L automatically changes operation to a Pulse Frequency Modulation (PFM) mode to minimize quiescent current draw from the battery. No intervention is necessary for a smooth transition from one mode to another. These two modes of operation allow the MCP1603/L to achieve the highest efficiency over the entire operating current range.

The MCP1603B device disables the PFM mode switching, and operates only in normal PWM mode over the entire load range (without skipping). MCP1603B is for applications that cannot tolerate the low-frequency output ripple associated with PFM switching.

The MCP1603/B/L family is available with either an adjustable or fixed-output voltage. The available fixed output voltage options for MCP1603/L are 1.2V, 1.5V, 1.8V, 2.5V and 3.3V, and for MCP1603B are 1.8 and 3.3V. When a fixed option is used, only three additional small external components are needed to form a complete solution. Couple this with the low profile, small-foot print packages and the entire system solution is achieved with minimal size.

Additional protection features include: UVLO, overtemperature and overcurrent protection.

• Over 90% Typical Efficiency
• Output Current Up To 500 mA
• Low PFM Quiescent Current = 45 μA, typical (MCP1603/L)
• Low Shutdown Current = 0.1 μA, typical
• Adjustable Output Voltage: 0.8V to 4.5V
• Fixed Output Voltage: 1.2V, 1.5V, 1.8V, 2.5V, 3.3V (MCP1603/L); 1.8V, 3.3V (MCP1603B)
• 2.0 MHz Fixed-Frequency PWM (Heavy Load)
• Automatic PWM-to-PFM Mode Transition (MCP1603/L)
• PWM Mode Only Option (MCP1603B)
• 100% Duty Cycle Operation
• Internally Compensated
• Undervoltage Lockout (UVLO)
• Overtemperature Protection
• Space Saving Packages: 5-Lead TSOT, Two Pinout Types (MCP1603/L); 8-Lead 3x3 DFN

• Cellular Telephones
• Portable Computers
• Organizers / PDAs
• USB Powered Devices
• Digital Cameras
• Portable Equipment
• +5V or +3.3V Distributed Systems
• Headsets