LT1309 Datasheet | Linear Technology

LT1309 500k Hz Micropower DC/DC Converter for Flash Memory Features s s s s s s s s s DESCRIPTIO s 60m A Output Current at 12V from 3V or 5V Supply Shutdown to 9µA VPP VALID parator Up to 85% Efficiency Switching Frequency: 500k Hz (Typical) Quiescent Current: 650µA Low VCESAT Switch: 300m V 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 Flash Memory VPP Generators Type II and III PCMCIA Card DC/DC Converters 3V to 12V, 5V to 12V Converters Portable puters and Instruments Cellular Telephones DC/DC Converter Module Replacements The LT ® 1309 is a 500k Hz micropower DC/DC converter for Flash Memory. The regulator Features Burst Mode TM operation with a 0.5A, 300m V 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 es in an 8-lead SO package allowing extremely pact 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 parator with a logic output that goes low when the output voltage is ready to program 12V Flash Memory. This parator simplifies the interface to external control logic. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a trademark of Linear Technology Corporation. TYPICAL APPLICATI VIN 3.3V TO 5V VIN VPP VALID ON/OFF 12V, 60m A Flash Memory Programming Supply L1- 10µH D1† VPP 12V, 60m A 84 82 EFFICIENCY (%) + C1 4.7µF VPP VALID SENSE LT1309 SOFT ON/OFF START PGND GND 80 78 76 74 72 VIN = 3.3V R1 1M C3 0.1µF C2 1µF- - - MURATA ERIE...