ML4961

October 1996 ML4961 Adjustable Output Low Voltage Boost Regulator with Detect GENERAL DESCRIPTION The ML4961 is a boost regulator designed for DC to DC conversion in 1 to 3 cell battery powered systems. The combination of BiCMOS process technology, internal synchronous rectification, variable frequency operation, and low supply current make the ML4961 ideal for 1 cell applications. The ML4961 is capable of start-up with input voltages as low as 1V, and the output voltage can be set anywhere between 2.5V and 6V by an external resistor divider connected to the SENSE pin. 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 ML4961 requires a minimum number of external components to build a very small adjustable regulator circuit 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 s s s s Guaranteed full load start-up and operation at 1V input Pulse Frequency Modulation and Internal Synchronous Rectification for high efficiency Minimum external components Low ON resistance internal switching FETs Micropower operation Adjustable output voltage (2.5V to 6...