LT1106

LT1106 Micropower Step-Up DC/DC Converter for PCMCIA Card Flash Memory FEATURES s s s s s s s s DESCRIPTIO 60mA Output Current at 12V from 3V Supply Shutdown to 10µA Programmable 12V or 5V Output Up to 85% Efficiency Quiescent Current: 750µA Low VCESAT Switch: 300mV at 0.5A Typical Uses Low Value, Thin, Surface Mount Inductors Ultra-Thin 20-Lead TSSOP Package APPLICATI s s s s S PCMCIA Card Flash Memory VPP Generator Portable Computers Portable Instruments DC/DC Converter Module Replacements The LT ®1106 is the industry’s first DC/DC converter designed for use on Type I and Type II PCMCIA cards. The device senses the VPP1 and VPP2 lines at the PCMCIA socket and generates a regulated 12V, 60mA programming supply if the socket does not provide it. Internal logic simplifies the interface to PCMCIA card microcontrollers. One input selects a 12V or 5V regulated output, while another input controls micropower shutdown. Two logic outputs indicate when the selected programming voltage is valid and whether the input supply is 3.3V or 5V. The regulator features Burst ModeTM operation with a 0.5A, 300mV switch for efficiency up to 85%. High frequency 500kHz switching permits the use of small value, flat inductors that fit neatly on PCMCIA cards. The device requires just 1µF of output capacitance. Quiescent current is 750µA which drops to 350µA when the card runs off the socket supply. The shutdown pin reduces supply current to only 10µA. The device includes a soft start feature w...