500-mA DC-DC Converter Provides I/O Flexibility

The MCP1601 500-mA dc-dc synchronous step-down converter operates over a multitude of input and output conditions. This unit enables designers to efficiently transform battery or bus voltages to its system requirements. It suits cell phones, PDAs, digital cameras, and USB-powered devices. Operating in three modes, the MCP1601 automatically switches between them to follow a maximum efficiency curve for the given I/O condition. These three modes include pulse-width modulation (PWM), pulse-frequency modulation (PFM), and low-dropout (LDO) mode. The converter's integrated safety features, such as overcurrent, overtemperature, and undervoltage lockout protection, safeguard the converter circuitry. Its externally controllable shutdown mechanism minimizes drain current during system inactivity. The unit's input voltage ranges from 2.7 to 5.5 V, its output voltage ranges from 0.9 V up to VIN, and the shutdown current is typically less than 0.1 mA. Packaged in an eight-pin MSOP, the MCP1601 costs $1.85 in 1000-piece quantities.