Datasheet Linear Technology LT1468

Datasheets

Prices

Packaging

Parametrics

Eco Plan

Application Notes

• Download
  Component and Measurement Advances Ensure 16-Bit DAC Settling Time &mdash AN74
  PDF, 980 Kb, File published: Jul 1, 1998
  DAC DC specifications are relatively easy to verify. AC specifications require more sophisticated approaches to produce reliable information. In particular, the settling time of the DAC and its output amplifier is extraordinarily difficult to determine to 16-bit resolution. This application note presents methods for 16-bit DAC settling time measurement and compares results. Appendices discuss oscilloscope overdrive, frequency compensation, circuit and optimization techniques, layout, power stages and a historical perspective of precision DACs.
  Extract from the document

  Application Note 74
  July 1998
  Component and Measurement Advances Ensure
  16-Bit DAC Settling Time
  The art of timely accuracy
  Jim Williams
  Introduction
  Instrumentation, waveform generation, data acquisition,
  feedback control systems and other application areas are
  beginning to utilize 16-bit data converters. More specifically, 16-bit digital-to-analog converters (DACs) have
  seen increasing use. New components (see Components
  for 16-Bit Digital-to-Analog Conversion, page 2) have
  made 16-bit DACs a practical design alternative1. These
  ICs provide 16-bit performance at reasonable cost compared to previous modular and hybrid technologies. The
  DC and AC specifications of the monolithic DAC’s
  approach or equal previous converters at significantly
  lower cost.
  DAC Settling Time
  DAC DC specifications are relatively easy to verify. Measurement techniques are well understood, albeit often
  tedious. AC specifications require more sophisticated
  approaches to produce reliable information. In particular,
  the settling time of the DAC and its output amplifier is
  extraordinarily difficult to determine to 16-bit resolution. …

• Download
  Linear Technology Magazine Circuit Collection, Volume V: Data Conversion, Interface and Signal Conditioning Products &mdash AN87
  PDF, 1.5 Mb, File published: Nov 1, 2000
  Application Note 87 is the fifth in a series that excerpts useful circuits from Linear Technology magazine. Data conversion, interface and signal conditioning circuits from issue VI:1 (February 1996) through issue VIII:4 (November 1998) are featured. Like its predecessor, AN67, this Application Note includes circuits for high speed video, interface and hot swap circuits, active RC and switched capacitor filter circuitry and a variety of data conversion and instrumentation circuits. All circuits are conveniently indexed by type.
  Extract from the document

  Application Note 87
  November 2000 Linear Technology Magazine Circuit Collection, Volume V
  Data Conversion, Interface and Signal Conditioning Products
  Richard Markell, Editor
  INTRODUCTION
  Application Note 87 is the fifth in a series that excerpts
  useful circuits from Linear Technology magazine to preserve them for posterity. This application note highlights
  data conversion, interface and signal conditioning circuits
  from issue VI:1 (February 1996) through issue VIII:4
  (November 1998). Like its predecessor, AN67, this Application Note includes circuits for high speed video, interface and hot swap circuits, active RC and switched capacitor filter circuitry and a variety of data conversion and instrumentation circuits. There are also several circuits
  that cannot be so neatly categorized. So, without further
  ado, I’ll let the authors describe their circuits.
  Note: Article Titles appear in this application note exactly
  as they originally appeared in Linear Technology magazine. This may result in some inconsistency in the usage
  of terminology. TABLE OF CONTENTS
  Introduction . 1
  DATA CONVERTERS
  The LTC®1446 and LTC1446L: World’s First Dual 12-Bit DACs in SO-8 Packages . 3
  Multichannel A/D Uses a Single Antialiasing Filter. 4
  LTC1454/54L and LTC1458/58L: Dual and Quad 12-Bit, Rail-to-Rail, Micropower DACs . 5
  Micropower ADC and DAC in SO-8 Give PC 12-Bit Analog Interface . 7
  The LTC1594 and LTC1598: Micropower 4-and 8-Channel 12-Bit ADCs . 10
  MUX the LTC1419 Without Software . 13 …

Design Notes

• Download
  DC Accurate Driver for the LTC2377-20 Achieves 2ppm Linearity &mdash DN1032
  PDF, 189 Kb, File published: Jan 6, 2014
  Extract from the document

  DC Accurate Driver for the LTC2377-20 Achieves
  2ppm Linearity – Design Note 1032
  Guy Hoover
  Introduction
  As resolution and sample rates continue to rise for
  analog-to-digital converters (ADCs), the driver circuitry
  for the ADC analog input, not the ADC itself, has increasingly become the limiting factor in determining
  overall circuit accuracy. First, the driver circuitry must
  buffer the input signal and provide gain. In addition,
  it must level shift or convert a single-ended signal to
  a fully differential signal to satisfy the input voltage
  range and common mode requirements of the ADC.
  All must be done without adding distortion to the
  original signal. by the LTC2377-20 (U1). The LTC2377-20 is a 20-bit,
  500ksps, low power SAR ADC with a typical integral
  nonlinearity (INL) of В±0.5ppm. The voltage at AIN is
  buffered by U4, which in turn drives the U5 resistor
  string, acting as a precision divider. U3 operates in
  a gain of minus one-half and drives the center of the
  U5 resistor string to maintain the ADC common mode
  voltage at VREF/2.
  U3 and U4 are LTВ®1468A low offset highly linear
  op amps. U5 is a LT5400A quad matched resistor …

• Download
  Selecting Op Amps for Precision 16-Bit DACs &mdash DN214
  PDF, 76 Kb, File published: Oct 1, 1999
  Extract from the document

  Selecting Op Amps for Precision 16-Bit DACs – Design Note 214
  Kevin R. Hoskins, Jim Brubaker and Patrick Copely
  The LTC В®1597 16-bit current output DAC offers a new
  level of accuracy and cost efficiency. It has exceptionally high accuracy and low drift: ±1LSB (max) INL and
  DNL over temperature. It eliminates costly external
  resistors in bipolar applications because it includes
  tightly trimmed, on-chip 4-quadrant resistors. To help
  achieve the best circuit DC performance, this design
  note offers two sets of easy-to-use design equations for
  evaluating an op amp’s effects on the DAC’s accuracy
  in terms of INL, DNL, offset (unipolar), zero (bipolar),
  unipolar and bipolar gain errors. With this information,
  selecting an op amp that gives the accuracy you need
  in a unipolar or bipolar application is easy.
  Figure 1 shows a unipolar application that combines the
  LTC1597 DAC and LTВ®1468 fast settling op amp. The
  equations for evaluating the effects of the op amp on
  the DAC’s accuracy are shown in Table 1. Quick work on
  Table 1’s equations with a calculator gives the results
  shown in Table 2. These are the changes the op amp can cause to the INL, DNL, unipolar offset and gain error
  of the DAC. Note, all are substantially less than 1LSB.
  Thus, the LT1468 is an excellent choice.
  The LTC1597’s internal design is very insensitive to …

Articles

• Download
  Component and Measurement Advances Ensure 16-Bit DAC Settling Time (Part One) &mdash LT Journal
  PDF, 262 Kb, File published: Aug 1, 1998
  Extract from the document

  DESIGN INFORMATION Component and Measurement
  Advances Ensure 16-Bit DAC
  by Jim Williams
  Settling Time (Part One)
  Introduction
  Instrumentation, waveform generation, data acquisition, feedback
  control systems and other application
  areas are beginning to utilize 16-bit
  data converters. More specifically, 16bit digital-to-analog converters (DACs)
  have seen increasing use. New components (see the sidebar “Components
  for 16-Bit Digital-to-Analog Conversion” on page 31) have made 16-bit
  DACs a practical design alternative.
  These ICs provide 16-bit performance
  at reasonable cost compared to previous modular and hybrid technologies.
  The DC and AC specifications of the
  monolithic DACs approach or equal
  previous converters at significantly
  lower cost. DAC Settling Time
  DAC DC specifications are relatively
  easy to verify. Measurement techniques are well understood, albeit often
  tedious. AC specifications require
  more sophisticated approaches to
  produce reliable information. In particular, the settling time of the DAC …

• Download
  A Composite Amplifier Topology Wrings More Performance Out of the LTC1597 16-Bit Current Output DAC &mdash LT Journal
  PDF, 146 Kb, File published: Mar 1, 2002
  Extract from the document

  DESIGN IDEAS A Composite Amplifier Topology
  Wrings More Performance Out of the
  LTC1597 16-Bit Current Output DAC
  by Derek Redmayne
  The LTC1597 16-bit current output
  DAC is capable of settling in the neighborhood of 1.7Вµs to 2Вµs using the
  16-bit accurate LT1468 as an I-V
  converter1. For applications needing
  higher throughput such as in-circuit
  testing, electrostatic sorting of organic materials, or electrostatic
  actuation of MEMS as examples, 1Вµs
  settling seems to be a common goal.
  This article shows a composite
  amplifier that can achieve settling in
  1Вµs.
  The topology shown in Figure 1
  combines the low noise, low offset,
  low input current qualities of the
  LT1468, with the fast slewing output
  of the LT1227. The output of the first
  stage is still taken as the node that
  drives the compensation capacitor,
  but the second stage, the LT1227, …

• Download
  LT1468: An Operational Amplifier for Fast, 16-Bit Systems &mdash LT Journal
  PDF, 221 Kb, File published: Nov 1, 1998
  Extract from the document

  DESIGN FEATURES LT1468: An Operational Amplifier
  for Fast, 16-Bit Systems
  by George Feliz
  Introduction
  The LT1468 is a single operational
  amplifier that has been optimized for
  accuracy and speed in 16-bit systems. Operating from В±15V supplies,
  the LT1468 in a gain of –1 configuration will settle in 900ns to 150µ V for
  a 10V step. The LT1468 also features
  the excellent DC specifications
  required for 16-bit designs. Input offset voltage is 75Вµ V max, input bias
  current is 10nA maximum for the
  inverting input and 40nA maximum
  for the noninverting input and DC
  gain is 1V/ВµV minimum. The LT1468
  specifications are summarized in
  Table 1. Two key applications that
  illustrate its use are current-to-voltage (I/V) conversion following a fast,
  16-bit current output digital-to-analog converter (DAC), such as LTC1597
  (Figure 1), and buffering the input of
  an analog-to-digital converter (ADC),
  such as the 333ksps LTC1604 (Figure 2). Both applications will be
  discussed in detail to highlight the …

Model Line

Manufacturer's Classification

• Signal Conditioning > Amplifiers > Operational Amplifiers (Op Amps) > High Speed Amplifiers (GBW > 50MHz) | Low Noise Amplifiers (