LT1309

LT1309 500kHz Micropower DC/DC Converter for Flash Memory FEATURES s s s s s s s s s DESCRIPTIO s 60mA Output Current at 12V from 3V or 5V Supply Shutdown to 9µA VPP VALID Comparator Up to 85% Efficiency Switching Frequency: 500kHz (Typical) Quiescent Current: 650µA Low VCESAT Switch: 300mV at 0.5A (Typical) Soft Start Reduces Supply Current Transients Uses Low Value, Small Size, Surface Mount Inductors Available in 8-Lead SO Package APPLICATI s s s s s s S Flash Memory VPP Generators Type II and III PCMCIA Card DC/DC Converters 3V to 12V, 5V to 12V Converters Portable Computers and Instruments Cellular Telephones DC/DC Converter Module Replacements The LT ® 1309 is a 500kHz micropower DC/DC converter for Flash Memory. The regulator features Burst ModeTM operation with a 0.5A, 300mV switch, enabling 85% efficiency at the fixed 12V output. High frequency operation permits the use of small value, and therefore small size, surface mount inductors and capacitors. The LT1309 comes in an 8-lead SO package allowing extremely compact PC board layouts. These features make the device attractive for PCMCIA cards, cellular phones and other applications where PC board space is limited. Quiescent current is 650µA decreasing to 9µA when the part shuts down. The device includes a soft start feature which limits supply current transients during turn-on. The LT1309 contains a VPP VALID comparator with a logic output that goes low when the output voltage is ready to program 12V Flash Me...