Datasheet Linear Technology LT1025

Datasheets

Prices

Packaging

Parametrics

Eco Plan

Application Notes

• Download
  Methods for Measuring Op Amp Settling Time &mdash AN10
  PDF, 277 Kb, File published: Jul 1, 1985
  The AN10 begins with a survey of methods for measuring op amp settling time. This commentary develops into circuits for measuring settling time to 0.0005%. Construction details and results are presented. Appended sections cover oscilloscope overload limitations and amplifier frequency compensation.
  Extract from the document

  Application Note 10
  July 1985
  Methods of Measuring Op Amp Settling Time
  Jim Williams
  Servo, DAC and data acquisition amplifiers all require
  good dynamic response. In particular, the time required
  for an amplifier to settle to final value after an input step
  is especially important. This specification allows setting
  a circuit’s timing margins with confidence that the data
  produced is accurate. The settling time is the total length
  of time from input step application until the amplifier remains within a specified error band around the final value. 10mV or less for a 10V step is of interest. No generalpurpose pulse generator is meant to hold output amplitude
  and noise within these limits. Generator output-caused
  aberration appearing at the oscilloscope probe will be
  indistinguishable from amplifier output movement, producing unreliable results. The oscilloscope connection
  presents additional problems. As probe capacitance rises,
  AC loading of the resistor junction will influence observed
  settling waveforms. The 20pF probe shown alleviates this
  problem but its 10X attenuation sacrifices oscilloscope
  gain. 1X probes are not suitable because of their excessive
  input capacitance. An active 1X FET probe will work, but
  another issue remains. Figure 1 shows one way to measure amplifier settling
  time (see References 1, 2, and 3). The circuit uses the
  “false sum node” technique. The resistors and amplifier …

• Download
  Thermocouple Measurement &mdash AN28
  PDF, 988 Kb, File published: Feb 1, 1988
  Considerations for thermocouple-based temperature measurement are discussed. A tutorial on temperature sensors summarizes performance of various types, establishing a perspective on thermocouples. Thermocouples are then focused on. Included are sections covering cold-junction compensation, amplifier selection, differential/isolation techniques, protection, and linearization. Complete schematics are given for all circuits. Processor- based linearization is also presented with the necessary software detailed.
  Extract from the document

  Application Note 28
  February 1988
  Thermocouple Measurement
  Jim Williams
  Introduction Thermocouples in Perspective In 1822, Thomas Seebeck, an Estonian physician, accidentally joined semicircular pieces of bismuth and copper
  (Figure 1) while studying thermal effects on galvanic arrangements. A nearby compass indicated a magnetic disturbance. Seebeck experimented repeatedly with different
  metal combinations at various temperatures, noting relative
  magnetic п¬Ѓeld strengths. Curiously, he did not believe that
  electric current was flowing, and preferred to describe the
  effect as “thermo-magnetism.” He published his results in
  a paper, “Magnetische Polarisation der Metalle und Erze
  durch Temperatur-Differenz” (see references). Temperature is easily the most commonly measured
  physical parameter. A number of transducers serve temperature measuring needs and each has advantages and
  considerations. Before discussing thermocouple-based
  measurement it is worthwhile putting these sensors in
  perspective. Figure 2’s chart shows some common contact
  temperature sensors and lists characteristics. Study reveals
  thermocouple strengths and weaknesses compared to
  other sensors. In general, thermocouples are inexpensive,
  wide range sensors. Their small size makes them fast and
  their low output impedance is a benefit. The inherent voltage output eliminates the need for excitation. Subsequent investigation has shown the “Seebeck Effect”
  to be fundamentally electrical in nature, repeatable, and
  quite useful. Thermocouples, by far the most common …

• Download
  Measurement and Control Circuit Collection &mdash AN45
  PDF, 1.2 Mb, File published: Jun 5, 1991
  A variety of measurement and control circuits are included in this application note. Eighteen circuits, including ultra low noise amplifiers, current sources, transducer signal conditioners, oscillators, data converters and power supplies are presented. The circuits emphasize precision specifications with relatively simple configurations.
  Extract from the document

  Application Note 45
  June 1991
  Measurement and Control Circuit Collection
  Diapers and Designs on the Night Shift
  Jim Williams
  Introduction
  During my wife’s pregnancy I wondered what it would
  really be like when the baby was finally born. Before that
  time, there just wasn’t much mothering and fathering to
  do. As a consolation, we busied ourselves watching the
  baby’s heartbeat (Figure 1) on a thrown-together fetal heart
  monitor (see References). feedings. As such, the circuits are annotated with the
  number of feedings required for their completion; e.g., a
  “3-bottle circuit” took three feedings. The circuit’s degree
  of difficulty, and Michael’s degree of cooperation, combined
  to determine the bottle rating, which is duly recorded in
  each figure.
  Low Noise and Drift Chopped Bipolar Amplifier
  Figure 2’s circuit combines the low noise of an LT®1028
  with a chopper based carrier modulation scheme to achieve
  an extraordinarily low noise, low drift DC amplifier. DC
  drift and noise performance exceed any currently available
  monolithic amplifier. Offset is inside 1ОјV, with drift less …

• Download
  Linear Technology Magazine Circuit Collection, Volume III &mdash AN67
  PDF, 1.2 Mb, File published: Sep 1, 1996
  Application Note 67 is a collection of circuits for data conversion, interface and signal processing from the first five years of Linear Technology. This application note includes circuits such as fast video multiplexers for high speed video, an ultraselective bandpass filter circuit with adjustable gain, and a fully differential, 8-channel, 12-bit A/D system. The categories included in this app note are data conversion, interface, filters, instrumentation, video/op amps and miscellaneous circuits.
  Extract from the document

  Application Note 67
  September 1996
  Linear Technology Magazine Circuit Collection, Volume III
  Data Conversion, Interface and Signal Processing
  Richard Markell, Editor
  INTRODUCTION
  Application Note 67 is a collection of circuits from the first
  five years of Linear Technology, targeting data conversion,
  interface and signal processing applications. This
  Application Note includes circuits such as fast video
  multiplexers for high speed video, an ultraselective
  bandpass filter circuit with adjustable gain and a fully differential, 8-channel, 12-bit A/D system. The categories
  included herein are data conversion, interface, filters,
  instrumentation, video/op amps and miscellaneous
  circuits. Application Note 66, which covers power products
  and circuits from Linear Technology ’s first five years, is
  also available from LTC. ARTICLE INDEX
  Data Conversion . 3
  Fully Differential, 8-Channel, 12-Bit A/D System Using the LTCВ®1390 and LTC1410 . 3
  12-Bit DAC Applications . 5
  LTC1329 Micropower, 8-Bit, Current Output DAC Used for Power Supply Adjustment,
  Trimmer Pot Replacement . 7
  12-Bit Cold Junction Compensated, Temperature Control System with Shutdown . 8 …

Design Notes

• Download
  Ultraprecise Instrumentation Amplifier Makes Robust Thermocouple Interface &mdash DN302
  PDF, 73 Kb, File published: Jan 1, 2003
  Extract from the document

  Ultraprecise Instrumentation Amplifier Makes
  Robust Thermocouple Interface – Design Note 302
  Jon Munson
  Introduction
  The versatile and precise LTC В®2053 instrumentation
  amplifier provides an excellent platform for robust, low
  power instrumentation products—as exemplified below
  by the battery-powered thermocouple amplifier circuit.
  The LTC2053 offers exceptionally low 10ОјV maximum
  input offset along with 116dB typical CMRR and PSRR,
  a result of a combination of switched capacitor and zerodrift op amp technologies. It is optimized for low voltage
  supplies from 2.7V to 11V single ended or up to В±5.5V with
  split supplies. The LTC2053 is ideal for battery-powered
  instrument applications because of its low 850ОјA typical
  current draw. The gain is easily programmed with two
  resistors, as shown in Figure 1, just like a traditional
  non-inverting op amp. The LTC2053 also features low
  1/f noise and rail-to-rail I/O to maximize dynamic range.
  The Requirements of Thermocouple Amplification
  A robust thermocouple amplification circuit must meet
  several specific requirements. First, a commonly used
  type K thermocouple develops 40.6ОјV/В°C, and a standard
  readout scale is 10mV/В°C, so a precision ampliп¬Ѓer with …

• Download
  Temperature Measurement Using Data Acquisition Systems &mdash DN5
  PDF, 77 Kb, File published: Mar 1, 1989
  Extract from the document

  Temperature Measurement Using Data Acquisition Systems
  Design Note 5
  William Rempfer and Guy Hoover
  Introduction
  Accurate temperature measurement is a difficult and
  very common problem. Whether recording a temperature, regulating a temperature or modifying a process
  to accommodate a temperature, the LTCВ®1090 family
  of data acquisition systems can provide an important
  link in the chain between the blast furnace temperature
  and the microcontroller. Features of the LTC1090 family
  can make temperature measurement easier, cheaper
  and more accurate.
  High DC input resistance and reduced span operation
  allow direct connection to many standard temperature
  sensors. Multiplexer options allow one chip to measure
  up to 8 channels of temperature information. Single
  supply operation, modest power requirements (~5mW)
  and serial interfaces make remote location possible.
  Switching power on and off lowers power consumption (560ОјW) even more for battery applications.
  Finally, because few sensors have accuracies as good as 0.1%, the 10-bit resolution and 0.05% accuracy of
  the LTC1090 family are just right for most temperature
  sensing applications.
  Thermocouple Systems …

Model Line

Manufacturer's Classification

• Signal Conditioning > Thermocouple Compensators