Datasheet Linear Technology LT1790BIS6-2.5

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LT1790 LT1790ACS6-1.25 LT1790ACS6-2.048 LT1790ACS6-2.5 LT1790ACS6-3 LT1790ACS6-3.3 LT1790ACS6-4.096 LT1790ACS6-5 LT1790AIS6-1.25 LT1790AIS6-2.048 LT1790AIS6-2.5 LT1790AIS6-3 LT1790AIS6-3.3 LT1790AIS6-4.096 LT1790AIS6-5 LT1790BCS6-1.25 LT1790BCS6-2.048 LT1790BCS6-2.5 LT1790BCS6-3 LT1790BCS6-3.3 LT1790BCS6-4.096 LT1790BCS6-5 LT1790BIS6-1.25 LT1790BIS6-2.048 LT1790BIS6-3 LT1790BIS6-3.3 LT1790BIS6-4.096 LT1790BIS6-5

Application Notes

• Download
  Current Sources for Fiber Optic Lasers: A Compendium of Pleasant Current Events &mdash AN90
  PDF, 409 Kb, File published: Apr 1, 2002
  A large group of fiber optic lasers are powered by DC current. Laser drive is supplied by a current source with modulation added to the signal. The current source, although conceptually simple, constitutes an extraordinarily tricky design problem. There are a number of practical requirements for a fiber optic current source and failure to consider them can cause laser and/or optical component destruction. This application note describes ten laser current source circuits with a range of capabilities. High and low current types are presented, along with designs for grounded anode, cathode or floating operation. Each circuit also includes laser protection features. Appended sections cover laser load simulation and current source noise measurement techniques.
  Extract from the document

  Application Note 90
  April 2002
  Current Sources for Fiber Optic Lasers
  A Compendium of Pleasant Current Events
  Jim Williams, Linear Technology Corporation
  INTRODUCTION
  A large group of fiber optic lasers are powered by DC
  current. Laser drive is supplied by a current source with
  modulation added further along the signal path. The
  current source, although conceptually simple, constitutes
  an extraordinarily tricky design problem. There are a
  number of practical requirements for a fiber optic current
  source and failure to consider them can cause laser and/
  or optical component destruction. Protection features must be included to prevent laser and
  optical component damage. The laser, an expensive and
  delicate device, must be protected under all conditions,
  including supply ramp up and down, improper control
  input commands, open or intermittent load connections
  and “hot plugging.”
  Detailed Discussion of Performance Issues Design Criteria for Fiber Optic Laser Current Sources It is useful to expand on the above cursory discussion to
  clarify design goals. As such, each previously called out
  issue is treated in greater detail below. Figure 1 shows a conceptual laser current source. Inputs
  include a current output programming port, an output …

Design Notes

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  Don't Be Fooled By Voltage Reference Long-Term Drift and Hysteresis &mdash DN229
  PDF, 98 Kb, File published: Apr 3, 2001
  Extract from the document

  Don’t Be Fooled by Voltage Reference Long-Term Drift
  and Hysteresis – Design Note 229
  John Wright Lies About Long-Term Drift
  Some manufacturers are now touting phenomenal
  long-term drift specifications, based on accelerated
  high temperature testing. THIS IS A DELIBERATE
  LIE! Long-term drift cannot be extrapolated from
  accelerated high temperature testing. The only way
  long-term drift can be determined is to measure it over
  the time interval of interest. The erroneous technique
  produces numbers that are wildly optimistic and uses
  the Arrhenius Equation to derive an acceleration factor
  from elevated temperature readings. The equation is:
  AF = e EA вЋ› 1 1 вЋћ
  ⎜ – ⎟
  K вЋќ T1 T2вЋ  where: E A = Activation Energy (Assume 0.7)
  K = Boltzmann’s Constant
  T2 = Test Condition in В°Kelvin
  T1 = Use Condition Temperature in В°Kelvin Equation the acceleration factor is 767 and the projected
  “bogus” long-term drift is 0.156ppm/1000hr at 30°C.
  For a 2.5V reference, this corresponds to a 0.39ОјV shift
  after 1000 hours. This is pretty hard to determine (read
  impossible) if the peak-to-peak output noise is larger …

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  Dual 25ВµV Micropower Op Amp Fits in 3mm x 3mm Package &mdash DN331
  PDF, 82 Kb, File published: Feb 2, 2004
  Extract from the document

  Dual 25ВµV Micropower Op Amp Fits in 3mm Г— 3mm Package
  Design Note 331
  Glen Brisebois
  Introduction
  Conventional monolithic micropower op amps with a
  wide supply voltage range require a large die area and
  therefore, a large package and footprint. The unconventional LTВ®6011 dual op amp п¬Ѓts 25ОјV input precision
  micropower operation and wide 2.7V to 36V supply range
  in a tiny new package—its 3mm × 3mm DFN package
  is so small it doesn’t even have leads. The LT6011 also
  provides rail-to-rail output swing and utilizes superbeta
  input transistors to achieve picoampere input currents.
  Hall Sensor Amplifier
  Figure 1 shows the LT6011 applied as a low power Hall
  sensor amplifier. The magnetic sensitivity of a Hall sensor is proportional to the DC excitation voltage applied
  across it. With a 1V bias voltage, the sensitivity of this
  Hall sensor is specified as 4mV/mTesla of magnetic
  п¬Ѓeld. At that level of DC bias, however, the 400О© bridge
  consumes 2.5mA. Reducing the excitation voltage would
  reduce the power consumption, but it would also reduce
  the sensitivity. This is where the beauty of precision
  micropower amplification becomes especially apparent.
  The LT1790-1.25 micropower reference provides a …

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  16-Bit ADC Simplifies Current Measurements &mdash DN341
  PDF, 78 Kb, File published: Jul 1, 2004
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  16-Bit ADC Simplifies Current Measurements
  Design Note 341
  Mark Thoren
  Introduction
  The LTC®2433-1 is a high performance 16-bit Delta-Sigma ADC for DC measurements. With an input noise floor
  of 1.45ОјVRMS and a reference range of 100mV to VCC,
  the input resolution and range can be optimized for a
  wide variety of applications. The flexible SPI interface
  can be configured to self-clock, simplifying isolation
  or level shifting of digital signals in applications where
  the ADC must be referenced to a different potential than
  the data acquisition system. asynchronous communication schemes such as RS232.
  Unfortunately, the internal oscillator tolerance makes it
  risky to receive all 19 bits asynchronously. One solution
  is to apply a crystal-controlled clock signal to the FO
  pin, but there is a simpler (and cheaper) way. Data Transfer
  Figure 1a shows a –48V telecom supply current monitor
  with a 5.4A full scale. The LTC2433-1 serial interface is
  configured for internal serial clock, continuous conversion mode. This mode is selected by tying chip select
  low and pulling SCK high at power-up. In this mode,
  the LTC2433-1 continuously converts at 6.8 samples
  per second and clocks out its data at a serial data rate
  of 17.5kHz В±2%, the tolerance of the internal oscillator. While a conversion is taking place, both SCK and SDO …

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  6-Channel SAR ADCs for Industrial Monitoring and Portable &mdash DN426
  PDF, 112 Kb, File published: Sep 14, 2007
  Extract from the document

  6-Channel SAR ADCs for Industrial Monitoring and Portable
  Instruments
  Design Note 426
  Guy Hoover and Steve Logan
  The 14-bit LTC2351-14 is a 1.5Msps, low power SAR
  ADC with six simultaneously sampled differential input
  channels. It operates from a single 3V supply and features
  six independent sample-and-hold amplifiers and a single
  ADC. The single ADC with multiple S/HAs enables excellent
  range match (1mV) between channels and channel-tochannel skew (200ps).
  The versatile LTC2351-14 is ideally suited for industrial
  monitoring applications such as 3-phase power line
  monitoring to ensure line voltage compliance, portable
  power line instrumentation, power factor correction, motor control, and data acquisition. These applications may
  be battery powered, and it is here that the LTC2351-14’s low power and small size are desirable. Power consumption is a mere 16.5mW, which extends battery life. The
  3-wire serial interface means fewer pins than parallel
  output devices, allowing the LTC2351-14 to п¬Ѓt in a 32-pin,
  5mm Г— 5mm QFN package.
  Power Line Monitoring Application
  Figure 1 shows a typical power line monitoring application.
  Current is sensed by a CR Magnetics CR8348-2500-N
  current transformer. An LT1790-1.25 biases the output
  of the transformer to the middle of the LTC2351-14 input …

• Download
  12-bit DAC in TSOT-23 Includes Bidirectional REF Pin for Connection to Op Amp or External High Precision Reference &mdash DN448
  PDF, 87 Kb, File published: Aug 25, 2008
  Extract from the document

  12-bit DAC in TSOT-23 Includes Bidirectional REF Pin for
  Connection to Op Amp or External High Precision Reference
  Design Note 448
  Kevin Wrenner, Troy Seman and Mark Thoren
  Introduction
  The LTC®2630’s combination of a 12-bit DAC and low-drift
  integrated reference in a tiny SC-70 package has proven
  popular for a wide variety of applications. Two new DACs,
  the LTC2631 and LTC2640, take this winning formula and
  further expand its reach by adding a bidirectional REF pin
  and an optional I2C interface in a tiny TSOT-23. The LT1991 precision op amp is a superb choice for
  amplifying or attenuating the DAC output to achieve a
  desired output range because it requires no precision
  external resistors. Its integrated, precision resistors are
  matched to 0.04%, allowing gain to be set by simple pin
  strapping (see the data sheet for a large variety of gain
  options). Figure 1 shows the configuration for a difference
  gain of 4, resulting in a В±5V output with 12-bit programmability under I2C control. Integral nonlinearity, seen in
  Figure 2, is better than 1LSB. Like their predecessor, these parts feature 1-bit INL and
  DNL, offer excellent load regulation driving up to 10mA
  loads, and can operate rail-to-rail. See Table 1 for a list
  of options. Figure 3 shows a negative output system using a similar
  setup, this time with the LT1991 conп¬Ѓgured as an inverting …

Articles

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  SOT-23 Voltage Reference Has 0.05% Initial Accuracy, 10ppm/°C Tempco, Operates on 35µA &mdash LT Journal
  PDF, 207 Kb, File published: Sep 1, 2000
  Extract from the document

  LINEAR TECHNOLOGY
  VOLUME X NUMBER 3 SEPTEMBER 2000 IN THIS ISSUE…
  COVER ARTICLE
  SOT-23 Voltage Reference Has
  0.05% Initial Accuracy, 10ppm/В°C
  Tempco, Operates on 35Вµ A . 1
  Richard Markell and John Wright Issue Highlights . 2
  LTCВ® in the News .2 SOT-23 Voltage Reference
  Has 0.05% Initial Accuracy,
  10ppm/В°C Tempco,
  Operates on 35ВµA DESIGN FEATURES
  Tiny SOT-23 Buck Regulator
  Accepts Inputs from 4V to 25V . 5 by Richard Markell and John Wright Jeff Witt Introduction Specifications Inverting Switching Regulator
  Delivers High Current/Low Noise
  Outputs in a SOT-23 .8 The LT1790 brings ultraprecision, low
  dropout voltage references to the world
  of the very small SOT-23 package.
  This new reference boasts 0.05%
  initial accuracy and 10ppm/В°C temperature coefficient, making it the
  ideal reference for handheld and portable instrumentation and equipment
  that requires a minimum of trimming. To ensure that handheld
  equipment stays calibrated for the
  long haul, the LT1790 has excellent …

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Manufacturer's Classification

• Signal Conditioning > Voltage References > Series Voltage References | Micropower Voltage References