Analog Devices

The LT1105 Offline Switching Regulator is designed for high input voltage applications using an external FET switch. The LT1105 is available and its totem pole output drives the gate of an external FET. Unique design of the LT1105 eliminates the need for an optocoupler while still providing ±1% load and line regulation in a magnetic flux-sensed converter. This significantly simplifies the design of offline power supplies and reduces the number of components which must cross the isolation barrier to one, the transformer.The LT1105 current mode switching techniques are well suited to transformer isolated flyback and forward topologies while providing ease of frequency compensation with a minimum of external components.APPLICATIONSUp to 250W Isolated Mains ConverterUp to 50W Isolated Telecom ConverterFully Isolated Multiple OutputsDistributed Power Conversion Networks

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.ApplicationsPalmtop Computers3V to 5V, 5V to 12V Converters24V to 5V, 12V to 5V ConvertersLCD Bias GeneratorsPeripherals and Add-On CardsBattery Backup SuppliesCellular TelephonesPortable Instruments

The LT1108 is a versatile micropower DC/DC converter. The device requires only four 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 LT1108 functions equally well in step-up, step-down, or inverting applications.The LT1108 is pin-for-pin compatible with the LT1173, but has a duty cycle of 70%, resulting in increased outputcurrent in many applications. The LT1108 can deliver 150mA at 5V from a 2 AA cell input and 5V at 300mA from 9V in step-down mode. Quiescent current is just 110µA, making the LT1108 ideal for power conscious battery-operated systems.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, under voltage lock-out circuit, or error amplifier.ApplicationsPalmtop Computers3V to 5V, 5V to 12V Converters9V to 5V, 12V to 5V ConvertersLCD Bias GeneratorsPeripherals and Add-On CardsBattery Backup SuppliesCellular Telephones

The LT1109 is a simple step-up DC/DC converter. Available in 8-pin SO, 3-lead TO-92 (fixed output only) or miniDIP packages, the devices require only three external components to construct a complete DC/DC converter. Current drain is just 320µA at no load, making the device ideal for cost-sensitive applications where standby current must be kept to a minimum.The LT1109-5 can deliver 5V at 100mA from a 3V input and the LT1109-12 can deliver 12V at 60mA from a 5V input. The 8-pin versions also feature a logic controlledSHUTDOWNpin that turns off the oscillator when taken low. The gated-oscillator design requires no frequency compensation components. The high frequency 120kHz oscillator permits the use of small surface mount inductors and capacitors. For a 5V to 12V at 120mA converter, see the LT1109A. For a 5V to 12V at 200mA converter with 20µA shutdown current, see the LT1301.ApplicationsFlash Memory VPP Generators3V to 5V Converters5V to 12V ConvertersDisk DrivesPC Plug-In CardsPeripheralsBattery-Powered Equipment

The LT1110 is a versatile micropower DC-DC converter. The device requires only three external components to deliver a fixed output of 5V or 12V. The very low minimum supply voltage of 1.0V allows the use of the LT1110 in applications where the primary power source is a single cell. An on-chip auxiliary gain block can function as a low battery detector or linear post regulator.The 70kHz oscillator allows the use of surface mount inductors and capacitors in many applications. Quiescent current is just 300µA, making the device ideal in remote or battery powered applications where current consumption must be kept to a minimum.The device can easily be configured as a step-up or step-down converter, although for most step-down applications or input sources greater than 3V, the LT1111 is recommended. Switch current limiting is user-adjustable by adding a single external resistor. Unique reverse battery protection circuitry limits reverse current to safe, non-destructive levels at reverse supply voltages up to 1.6V.ApplicationsPagersCamerasSingle-Cell to 5V ConvertersBattery Backup SuppliesLaptop and Palmtop ComputersCellular TelephonesPortable InstrumentsLaser Diode DriversHand-Held Inventory Computers

The LT1111 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 LT1111 functions equally well in step-up, step-down, or inverting applications.The LT1111 oscillator is set at 72kHz, optimizing the device to work with off-the-shelf surface mount inductors. The device can deliver 5V at 100mA from a 3V input in step-up mode or 5V at 200mA from a 12V input in step-down mode.Switch current limit can be programmed with a single resistor. An auxiliary open-collector gain block can be configured as a low-battery detector, linear post regulator, undervoltage lock-out circuit, or error amplifier.For input sources of less than 2V use the LT1110.Applications3V to 5V, 5V to 12V Converters9V to 5V, 12V to 5V ConvertersRemote ControlsPeripherals and Add-On CardsBattery Backup SuppliesUninterruptible SuppliesLaptop and Palmtop ComputersCellular TelephonesPortable InstrumentsFlash Memory VPP Generators

The LT1112 dual and LT1114 quad op amps achieve a new standard in combining low cost and outstanding precision specifications.The performance of the selected prime grades matches or exceeds competitive devices. In the design of the LT1112/LT1114 however, particular emphasis has been placed on optimizing performance in the low cost plastic and SO packages. For example, the 75µV maximum offset voltage in these low cost packages is the lowest on any dual or quad non-chopper op amp.The LT1112/LT1114 also provide a full set of matching specifications, facilitating their use in such matching dependent applications as two and three op amp instrumentation amplifiers.Another set of specifications is furnished at ±1V supplies. This, combined with the low 320µA supply current per amplifier, allows the LT1112/LT1114 to be powered by two nearly discharged AA cells.ApplicationsPicoampere/Microvolt InstrumentationTwo and Three Op Amp Instrumentation AmplifersThermocouple and Bridge AmplifiersLow Frequency Active FiltersPhoto Current AmplifiersBattery-Powered Systems

The LT1113 achieves a new standard of excellence in noise performance for a dual JFET op amp. The 4.5nV/√Hz1kHz noise combined with low current noise and picoampere bias currents makes the LT1113 an ideal choice for amplifying low level signals from high impedance capacitive transducers.The LT1113 is unconditionally stable for gains of 1 or more, even with load capacitances up to 1000pF. Other key features are 0.4mV VOS and a voltage gain of 4 million. Each individual amplifier is 100% tested for voltage noise, slew rate and gain bandwidth.The design of the LT1113 has been optimized to achieve true precision performance with an industry standard pinout in the S0-8 package. A set of specifications are provided for ±5V supplies and a full set of matching specifications are provided to facilitate the use of the LT1113 in matching dependent applications such as instrumentation amplifier front ends.ApplicationsPhotocurrent AmplifiersHydrophone AmplifiersHigh Sensitivity Piezoelectric AccelerometersLow Voltage and Current Noise Instrumentation Amplifier Front EndsTwo and Three Op Amp Instrumentation AmplifiersActive Filters