MCP1603/B/L 2.0 MHz, 500 mA Synchronous Buck Regulator Features General Description Over 90% Typical Efficiency The MCP1603/B/L is a high-efficiency, fully-integrated 500 mA synchronous buck regulator whose 2.7V to Output Current Up To 500 mA 5.5V input voltage range makes it ideally suited for Low PFM Quiescent Current = 45 A, typical applications powered from 1-cell Li-Ion or 2-cell/3-cell (MCP1603/L) NiMH/NiCd batteries. Low Shutdown Current = 0.1 A, typical At heavy loads, the MCP1603/B/L operates in the Adjustable Output Voltage: 2.0MHz fixed frequency pulse-width modulation - 0.8V to 4.5V (PWM) mode, which provides a low noise, low-output Fixed Output Voltage: ripple, small-size solution. When the load is reduced to - 1.2V, 1.5V, 1.8V, 2.5V, 3.3V (MCP1603/L) light levels, the MCP1603/L automatically changes operation to a Pulse Frequency Modulation (PFM) - 1.8V, 3.3V (MCP1603B) mode to minimize quiescent current draw from the 2.0 MHz Fixed-Frequency PWM (Heavy Load) battery. No intervention is necessary for a smooth Automatic PWM-to-PFM Mode Transition transition from one mode to another. These two modes (MCP1603/L) of operation allow the MCP1603/L to achieve the PWM Mode Only Option (MCP1603B) highest efficiency over the entire operating current 100% Duty Cycle Operation range. Internally Compensated The MCP1603B device disables the PFM mode Undervoltage Lockout (UVLO) switching, and operates only in normal PWM mode Overtemperature Protection over the entire load range (without skipping). MCP1603B is for applications that cannot tolerate the Space Saving Packages: low-frequency output ripple associated with PFM - 5-Lead TSOT, Two Pinout Types (MCP1603/L) switching. - 8-Lead 2 x 3 DFN The MCP1603/B/L family is available with either an adjustable or fixed-output voltage. The available fixed Applications output voltage options for MCP1603/L are 1.2V, 1.5V, Cellular Telephones 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 Portable Computers small external components are needed to form a Organizers / PDAs complete solution. Couple this with the low profile, USB Powered Devices small-foot print packages and the entire system Digital Cameras solution is achieved with minimal size. Portable Equipment Additional protection features include: UVLO, +5V or +3.3V Distributed Systems overtemperature and overcurrent protection. Headsets 2007-2012 Microchip Technology Inc. DS22042B-page 1MCP1603/B/L Package Types MCP1603/MCP1603B MCP1603L MCP1603 TSOT TSOT 2x 3 DFN* L 1 8 GND V /V X V 1 5 L SHDN 1 5 FB OUT IN X NC 2 7 V EP IN GND 2 GND 2 9 SHDN NC 3 6 V /V 4 5 NC L V FB OUT SHDN34 V /V 34 X IN FB OUT * Includes Exposed Thermal Pad (EP) see Table 3-1. Typical Application Circuit L V V 1 IN OUT 4.7 H 2.7V to 4.5V 1.8V 500 mA V L X IN C C IN OUT 4.7 F V 4.7 F SHDN FB GND 100 V = 2.7V V = 1.8V IN OUT 90 80 70 60 50 40 V = 3.6V IN V = 4.5V IN 3030 PFM/PWM (MCP1603/L) 20 --- PWM (MCP1603B) 10 0.1 1 10 100 1000 Output Current (mA) DS22042B-page 2 2007-2012 Microchip Technology Inc. Efficiency (%)