Analog Devices Inc./Maxim Integrated

The LT1025 is a micropower thermocouple cold junction compensator for use with type E, J, K, R, S, and T thermocouples. It utilizes wafer level and post-package trimming to achieve 0.5°C initial accuracy. Special curvature correction circuitry is used to match the "bow" found in all thermocouples so that accurate cold junction compensation is maintained over a wider temperature range.The LT1025 will operate with a supply voltage from 4V to 36V. Typical supply current is 80µA, resulting in less than 0.1°C internal temperature rise for supply voltages under 10V. A 10mV/°C output is available at low impedance, in addition to the direct thermocouple voltages of 60.9µV/°C (E), 51.7µV/°C (J), 40.3µV/°C (K, T) and 5.95µV/°C (R, S). All outputs are essentially independent of power supply voltage.A special kit is available (LTK001) which contains an LT1025 and a custom tailored thermocouple amplifier. The amplifier and compensator are matched to allow a much tighter specification of temperature error than would be obtained by adding the compensator and amplifier errors on a worst-case basis. The amplifier from this kit is available separately as LTKA0x.The LT1025 is available in either an 8-pin PDIP or 8-pin SO package for temperatures between 0°C and 70°C.ApplicationsThermocouple Cold Junction CompensatorCentigrade ThermometerTemperature Compensation Network

The LT1027LS8 is a precision reference that combines low drift and noise with excellent long-term stability and high output accuracy. The reference output will source up to 15mA and sink up to 10mA, and remain constant with input voltage variations.The hermetic package provides outstanding humidity and thermal hysteresis performance. The LT1027LS8 is only 5mm × 5mm × 1.5mm, offering an alternative to large through-hole metal can voltage references, such as the industry standard LT1021. The LT1027LS8 offers similar performance to the LT1027, with additional stability from the hermetic package.LT1027LS8 is based on a buried Zener diode structure, which enables temperature and time stability, and extremely low noise performance of < 1ppm peak-to-peak. The LT1027LS8 operates on a supply voltage from 8V up to 40V. The subsurface Zener exhibits better time stability than even the best bandgap reference, and the hermetic package maintains that stability over a wide range of environmental conditions.PackageLT1027N-8, S-8LT1027LS8LS8 Hermetic, Low DriftApplicationsInstrumentation and Test EquipmentHigh Resolution Data Acquisition SystemsA/D and D/A ConvertersPrecision RegulatorsPrecision ScalesDigital Voltmeters

The LT1028 (gain of –1 stable)/LT1128(gain of +1 stable) achieve a new standard of excellence in noise performance with 0.85nV/√Hz1kHz noise, 1.0nV/√Hz10Hz noise. This ultralow noise is combined with excellent high speed specifications (gain-bandwidth product is 75MHz for LT1028, 20MHz for LT1128), distortion-free output, and true precision parameters (0.1µV/°C drift, 10µV offset voltage, 30 million voltage gain). Although the LT1028/LT1128 input stage operates at nearly 1mA of collector current to achieve low voltage noise, input bias current is only 25nA.The LT1028/LT1128’s voltage noise is less than the noise of a 50Ω resistor. Therefore, even in very low source impedance transducer or audio amplifier applications, the LT1028/LT1128’s contribution to total system noise will be negligible.ApplicationsLow Noise Frequency SynthesizersHigh Quality AudioInfrared DetectorsAccelerometer and Gyro Amplifiers350 ohms Bridge Signal ConditioningMagnetic Search Coil AmplifiersHydrophone Amplifiers

The LT1029 is a 5V bandgap reference intended for use in the shunt or "Zener" mode, allowing it to be used as either a positive or negative reference. The output is pretrimmed to ± 0.2% accuracy with 20ppm/°C maximum temperature drift. A trim pin allows additional output adjustment for even more precise output voltage.Operating current range for the LT1029 is 700μA to 10mA. Extremely low dynamic impedance allows excellent output regulation even with fluctuating operating current.The LT1029 will replace an LM136-5 or LM336-5 and simplify circuits using the "minimum temperature coefficient" trim network. The LT1029 does not require this special network to meet its temperature drift specification; these application network components are simply removed. If output trimming is required for initial accuracy, the diodes in the trim network should be replaced with jumpers.ApplicationsA-to-D and D-to-A ConvertersPrecision RegulatorsPrecision Current SourcesV to F and F to V Converters

The LT1032 is a RS232 and RS423 line driver that operates over a ±5V to ±15V range on low supply current and can be shut down to zero supply current. Outputs are fully protected from externally applied voltages of ±30V by both current and thermal limiting. Since the output swings to within 200mV of the positive supply and 600mV of the negative supply, power supply needs are minimized.Also included is a strobe pin to force all outputs low independent of input or shutdown conditions. Further, slew rate can be adjusted with a resistor connected to the supply.A major advantage of the LT1032 is the high impedance output state when off or powered down.For applications requiring dual or triple RS232 driver/receiver devices, see the LT1180A (dual), LT1039A (triple) or the LT1130A data sheets.ApplicationsRS232Power Supply InverterMicropower InterfaceLevel Translator