Analog Devices LT1107 Product Info

• Operates at Supply Voltages from 2V to 30V
• Consumes Only 320µA Supply Current
• Works in Step-Up or Step-Down Mode
• Only Three External Components Required
• Low-Battery Detector Comparator On-Chip
• User Adjustable Current Limit
• Internal 1A Power Switch
• Fixed or Adjustable Output Voltage Versions
• Space Saving 8-Pin MiniDIP or SO-8 Package

The LT1107 is a versatile micropower DC/DC converter. The device requires only three external components to deliver a fixed output of 5V or 12V. Supply voltage ranges from 2V to 12V in step-up mode and to 30V in step-down mode. The LT1107 functions equally well in step-up, step-down, or inverting applications.

The LT1107 is pin-for-pin compatible with the LT1111, but has a duty cycle of 70%, resulting in increased output current in many applications. The LT1107 can deliver 150mA at 5V from a 2AA cell input and 5V at 300mA from 24V in step-down mode. Quiescent current is just 320µA, making the LT1107 ideal for power-conscious battery operated systems. The 63kHz oscillator is optimized to work with surface mount inductors and capacitors.

Switch current limit can be programmed with a single resistor. An auxiliary gain block can be configured as a low-battery detector, linear post regulator, undervoltage lock-out circuit, or error amplifier.

Applications

• Palmtop Computers
• 3V to 5V, 5V to 12V Converters
• 24V to 5V, 12V to 5V Converters
• LCD Bias Generators
• Peripherals and Add-On Cards
• Battery Backup Supplies
• Cellular Telephones
• Portable Instruments