Analog Devices

The LTC1438/LTC1439 are dual, synchronous stepdown switching regulator controllers which drive external N-channel power MOSFETs in a phase-lockable fixed frequency architecture. The Adaptive Power™output stage selectively drives two N-channel MOSFETs at frequencies up to 400kHz while reducing switching losses to maintain high efficiencies at low output currents.An auxiliary 0.5A linear regulator using an external PNP pass device provides a low noise, low dropout voltage source. A secondary winding feedback control pin (SFB1) guarantees regulation regardless of load on the main output by forcing continuous operation.An additional comparator is available for use as a low battery detector. A power-on reset timer (POR) is included which generates a signal delayed by 65536/fCLK(typ 300ms) after the output is within 5% of the regulated output voltage. Internal resistive dividers provide pin selectable output voltages with remote sense capability on one of the two outputs.The operating current levels are user-programmable via external current sense resistors. Wide input supply range allows operation from 3.5V to 30V (36V maximum).ApplicationsNotebook and Palmtop Computers, PDAsPortable InstrumentsBattery-Operated DevicesDC Power Distribution Systems

The LTC1440 is an ultralow power comparator with a built-in voltage reference. The comparator features less than 4.0µA supply current over temperature. The internal reference is 1.182V with ±1% accuracy. The LTC1440 has programmable hysteresis and TTL/CMOS outputs that sink and source current. The reference output can drive a bypass capacitor of up to 0.01µF without oscillation.The comparators operate from a single 2V to 11V supply or a dual ±1V to ±5.5V supply. Comparator hysteresis is easily programmed by using two resistors and the HYST pin. Each comparator’s input operates from the negative supply to within 1.3V of the positive supply. The comparator output stage can continuously source up to 40mA. By eliminating the cross-conducting current that normally happens when the comparator changes logic states, the power supply glitches are eliminated.The LTC1440 is available in a 3mm × 3mm × 0.75mm DFN package, as well as 8-pin PDIP and SO-8.ApplicationsBattery-Powered System MonitoringThreshold DetectorsWindow ComparatorsOscillator Circuits

The LTC1441 is an ultralow power dual comparator, featuring less than 5.7µA supply current over temperature. The TTL/CMOS outputs both sink and source current.The comparators operate from a single 2V to 11V supply or a dual ±1V to ±5.5V supply. Each comparator’s input operates from the negative supply to within 1.3V of the positive supply. The comparator output stage can continuously source up to 40mA. By eliminating the cross-conducting current that normally happens when the comparator changes logic states, the power supply glitches are eliminated.The LTC1441 is available in an 8-pin PDIP and SO package.ApplicationsBattery-Powered System MonitoringThreshold DetectorsWindow ComparatorsOscillator Circuits

The LTC1442 is an ultralow power dual comparator with a built-in voltage reference. The comparators feature less than 5.7µA supply current over temperature, a 1.182V ±1% reference, programmable hysteresis and TTL/CMOS outputs that sink and source current. The voltage reference output can drive a bypass capacitor of up to 0.01µF without oscillation.The comparators operate from a single 2V to 11V supply or a dual ±1V to ±5.5V supply. Comparator hysteresis is easily programmed by using two resistors and the HYST pin. Each comparator’s input operates from the negative supply to within 1.3V of the positive supply. The comparator output stage can continuously source up to 40mA. By eliminating the cross-conducting current that normally happens when the comparator changes logic states, the power supply glitches are eliminated.The LTC1442 is available in an 8-pin PDIP and SO package.ApplicationsBattery-Powered System MonitoringThreshold DetectorsWindow ComparatorsOscillator Circuits

The LTC1443/LTC1444/LTC1445 are ultralow power quad comparators with a built-in reference. The comparators feature less than 8.5μA supply current over temperature, an internal reference (1.182V ±1% for LTC1443 or 1.221V ±1% for LTC1444/LTC1445), programmable hysteresis LTC1444/LTC1445) and TTL/CMOS output (LTC1443/ LTC1445) that sinks and sources current (open-drain output for LTC1444). The reference output can drive a bypass capacitor of up to 0.01μF without oscillation.The comparators operate from a single 2V to 11V supply or a dual ±1V to ±5.5V supply (LTC1443). Comparator hysteresis is easily programmable using two resistors and the HYST pin (LTC1444/LTC1445). Each comparator’s input operates from the negative supply to within 1.3V of the positive supply. The LTC1443/LTC1445 comparator output stage can continuously source up to 40mA. By eliminating the cross-conducting current that normally happens when the comparator changes logic states, power supply glitches are eliminated.The LTC1443/LTC1444/LTC1445 are available in the 16-pin SO, PDIP and DFN packages.ApplicationsBattery-Powered System MonitoringThreshold DetectorsWindow ComparatorsOscillator Circuits

The LTC1443/LTC1444/LTC1445 are ultralow power quad comparators with a built-in reference. The comparators feature less than 8.5μA supply current over temperature, an internal reference (1.182V ±1% for LTC1443 or 1.221V ±1% for LTC1444/LTC1445), programmable hysteresis (LTC1444/LTC1445) and TTL/CMOS output (LTC1443/ LTC1445) that sinks and sources current (open-drain output for LTC1444). The reference output can drive a bypass capacitor of up to 0.01μF without oscillation.The comparators operate from a single 2V to 11V supply or a dual ±1V to ±5.5V supply (LTC1443). Comparator hysteresis is easily programmable using two resistors and the HYST pin (LTC1444/LTC1445). Each comparator’s input operates from the negative supply to within 1.3V of the positive supply. The LTC1443/LTC1445 comparator output stage can continuously source up to 40mA. By eliminating the cross-conducting current that normally happens when the comparator changes logic states, power supply glitches are eliminated.The LTC1443/LTC1444/LTC1445 are available in the 16-pin SO, PDIP and DFN packages.ApplicationsBattery-Powered System MonitoringThreshold DetectorsWindow ComparatorsOscillator Circuits

The LTC1443/LTC1444/LTC1445 are ultralow power quad comparators with a built-in reference. The comparators feature less than 8.5μA supply current over temperature, an internal reference (1.182V ±1% for LTC1443 or 1.221V ±1% for LTC1444/LTC1445), programmable hysteresis (LTC1444/LTC1445) and TTL/CMOS output (LTC1443/ LTC1445) that sinks and sources current (open-drain output for LTC1444). The reference output can drive a bypass capacitor of up to 0.01μF without oscillation.The comparators operate from a single 2V to 11V supply or a dual ±1V to ±5.5V supply (LTC1443). Comparator hysteresis is easily programmable using two resistors and the HYST pin (LTC1444/LTC1445). Each comparator’s input operates from the negative supply to within 1.3V of the positive supply. The LTC1443/LTC1445 comparator output stage can continuously source up to 40mA. By eliminating the cross-conducting current that normally happens when the comparator changes logic states, power supply glitches are eliminated.The LTC1443/LTC1444/LTC1445 are available in the 16-pin SO, PDIP and DFN packages.ApplicationsBattery-Powered System MonitoringThreshold DetectorsWindow ComparatorsOscillator Circuits

The LTC1446/LTC1446L are dual 12-bit digital-to-analog converters (DACs) available in an SO-8 package. They are complete with a rail-to-rail voltage output amplifier, an internal reference and an easy-to-use 3-wire cascadable serial interface.The LTC1446 has an internal reference and a full-scale output of 4.095V. It operates from a single 4.5V to 5.5V supply.The LTC1446L has an internal reference and a full-scale output of 2.5V. It operates from a single 2.7V to 5.5V supply.The low power supply current makes the LTC1446 family ideal for battery-powered applications. These DACs are available in space saving 8-pin SO and PDIP packages and require no external components for operation.ApplicationsDigital CalibrationIndustrial Process ControlAutomatic Test EquipmentCellular Telephones

The LTC1448 is a dual rail-to-rail voltage output, 12-bit digital-to-analog converter (DAC). It includes rail-to-rail output buffer amplifiers and an easy-to-use 3-wire serial interface. It is available in 8-pin SO and PDIP packages and provides the smallest footprint of any dual 12-bit DAC.The LTC1448 has an external reference input pin (REF) and its outputs swing from 0V to REF. The REF input can be tied to VCCproviding rail-to-rail operation from supplies of 2.7V to 5.5V. (For devices with internal reference see the LTC1446 data sheet.) The LTC1448 dissipates 2.5mW from a 5V supply.The low power supply current and the small SO-8 package make the LTC1448 ideal for battery-powered applications.ApplicationsDigital CalibrationIndustrial Process ControlAutomatic Test EquipmentCellular Telephones

The LTC1450/LTC1450L are complete single supply, rail-to-rail voltage output, 12-bit digital-to-analog converters (DACs) in a 24-pin SSOP or PDIP package. They include an output buffer amplifier, reference and a double buffered parallel digital interface.The LTC1450 operates from a 4.5V to 5.5V supply. The output can be pin strapped for 4.095V or 2.048V full-scale. It has a 2.048V internal reference.The LTC1450L operates from a 2.7V to 5.5V supply. The output can be pin strapped for 2.5V or 1.22V full-scale. It has a 1.22V internal reference.The LTC1450/LTC1450L offer true stand-alone performance. In addition, the reference output, high and low reference inputs and gain setting resistor are brought to pins for maximum flexibility.ApplicationsDigital CalibrationIndustrial Process ControlAutomatic Test EquipmentArbitrary Function GeneratorsBattery-Powered Data Conversion ProductsFeedback Control Loops and Gain Control