ML4950

Tem ommercial Extended C 70˚C to C 0˚ -2 ment dheld Equip an H e bl ta or for P G FEATURIN ge perature Ran July 2000 ML4950* Adjustable Output, Low Current Single Cell Boost Regulator with Detect GENERAL DESCRIPTION The ML4950 is a low power boost regulator designed for low voltage DC to DC conversion in single cell battery powered systems. The maximum switching frequency can exceed 100kHz, allowing the use of small, low cost inductors. The combination of integrated synchronous rectification, variable frequency operation, and low supply current make the ML4950 ideal for single cell applications. The ML4950 is capable of start-up with input voltages as low as 1V, and the output voltage can be set anywhere between 2V and 3V. An integrated synchronous rectifier eliminates the need for an external Schottky diode and provides a lower forward voltage drop, resulting in higher conversion efficiency. In addition, low quiescent battery current and variable frequency operation result in high efficiency even at light loads. The ML4950 requires a minimum number of external components and is capable of achieving conversion efficiencies in excess of 90%. The circuit also contains a RESET output which goes low when the IC can no longer function due to low input voltage, or when the DETECT input drops below 200mV. FEATURES s s Guaranteed full load start-up and operation at 1V input Pulse Frequency Modulation (PFM) and internal synchronous rectification for high efficiency Minimum exter...