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LTC6655

Application Notes

• Download
  Circuitry for Signal Conditioning and Power Conversion &mdash AN75
  PDF, 508 Kb, File published: Mar 1, 1999
  This publication includes designs for data converters and signal conditioners, transducer circuits, crystal oscillators and power converters. Wideband and micropower circuitry receive special attention. Tutorials on micropower design techniques and parasitic effects of test equipment are included.
  Extract from the document

  Application Note 75
  March 1999
  Circuitry for Signal Conditioning and
  Power Conversion
  Designs From a Once Lazy Sabbatical
  Jim Williams
  Introduction
  Linear Technology has a sabbatical program. Every five
  years employees are granted sabbatical leave, which may
  last up to six weeks. You have 18 months from each five
  year employment anniversary to take the leave. Sabbatical
  is fully company paid and has no restrictions. The time is
  yours to do with as you please.
  People exercise all degrees of freedom with their sabbaticals. They go sailing, they go to South Sea islands, they ski
  some mountain nobody ever heard of, they trek in Nepal.
  Houses get fixed, cars restored and children played with.
  For my third sabbatical I resolved to do absolutely nothing.
  For the first time in my life I was really tired, and I knew it.
  A six week rest sounded just fine. I’d walk the dog and
  spend time with my wife and son. That’s it. No transistors,
  no resistors, no op amps and, above all, no writing. I was
  so written out the thought of picking up a pencil produced
  an instant headache. …

• Download
  Instrumentation Applications for a Monolithic Oscillator: A Clock for All Reasons &mdash AN93
  PDF, 1.1 Mb, File published: Feb 1, 2003
  Instrumentation applications for a monolithic programmable oscillator are presented in this publication. Circuits include platinum and thermistor based thermometers, an isolated thermometer and three relative humidity signal conditioners. Bipolar and FET input chopper stabilized amplifiers with noise below 45nV (0.1Hz to 10Hz) are detailed. Two clock tunable sine wave generators with settable amplitude appear, as well as a tunable notch filter, an interval generator and an A to D converter. The oscillator's performance is contrasted against other approaches and its interval operation discussed.
  Extract from the document

  Application Note 93
  February 2003
  Instrumentation Applications for a Monolithic Oscillator
  A Clock for All Reasons
  Jim Williams INTRODUCTION Clock Types Oscillators are fundamental circuit building blocks. A
  substantial percentage of electronic apparatus utilize oscillators, either as timekeeping references, clock sources,
  for excitation or other tasks. The most obvious oscillator
  application is a clock source in digital systems.1 A second
  area is instrumentation. Transducer circuitry, carrier based
  amplifiers, sine wave formation, filters, interval generators and data converters all utilize different forms of
  oscillators. Although various techniques are common, a
  simply applied, broadly tunable oscillator with good accuracy has not been available. Commonly employed oscillators are resonant element
  based or RC types.2 Figure 1 shows two of each. Quartz
  crystals and ceramic resonators offer high initial accuracy
  and low drift (particularly quartz) but are essentially
  untunable over any significant range. Typical RC types
  have lower initial accuracy and increased drift but are
  easily tuned over broad ranges. A problem with conventional RC oscillators is that considerable design effort is
  required to achieve good specifications. A new device, the
  LTC1799, is also an RC type but fills the need for a simply
  applied, broadly tunable, accurate oscillator. Its accuracy
  and drift specifications fit between resonator based types
  and typical RC oscillators. Additionally, its board footprint, …

Design Notes

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  UL Isolated Self-Powered Sensing &mdash DN204
  PDF, 80 Kb, File published: Apr 3, 1999
  Extract from the document

  advertisement UL Isolated Self-Powered Sensing – Design Note 204
  Wayne Shumaker
  Introduction
  One of the major drawbacks with isolated sensing is the
  need for an isolated power supply. The LTCВ®1531 combines an isolated voltage comparator and voltage reference powered through its own internal capacitive isolation
  barrier. This barrier provides 2500VRMS of isolation. The
  LTC1531 provides a way to design control circuits that
  require an isolated sensor, such as a thermistor, thermocouple or R-bridge sensor, with power and signal communication across an isolation barrier. Often there is
  enough power available on the isolated side to deliver
  several microamps of continuous power to external micropower sensor circuits, or alternatively several milliamps
  for short durations.
  The LTC1531 powers the isolated side with a voltage
  pump driving the internal isolation caps formed in the lead
  frame. This voltage is rectified and stored on the isolated
  side. Periodically, the voltage pump stops and, if the
  isolated side has stored approximately 3.3V on an external capacitor, a comparison is done with the result sent
  back to the powered side where it is latched. This latched
  result can be used with the internal zero-cross comparator, with pulsed output, for controlling a triac. To aid in the
  isolated comparison, there is a 2.5V, 5mA, 100Вµs pulsed
  reference, VREG. The isolated comparator samples at the
  , LTC and LT are registered trademarks of Linear Technology Corporation.
  AC
  120V …

Articles

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  Avoid Debugging Cycles in Power Management for FPGA, GPU and ASIC Systems &mdash LT Journal
  PDF, 3.2 Mb, File published: Aug 25, 2016
  Extract from the document

  Avoid Debugging Cycles in Power Management for FPGA,
  GPU and ASIC Systems
  Afshin Odabaee When it comes to designing FPGA, GPU or ASIC controlled systems, the number of
  design challenges related to power management and analog systems pale in comparison
  to those related to digital design. Nevertheless, it is risky to assume that power system
  design can be left to “later,” or taken in line with digital design. Even seemingly innocuous
  problems in power supply design can significantly delay the release of a system, as any
  added time to the power system debugging cycle can halt all work on the digital side.
  A good way to put DC/DC regulation
  issues to rest is to use a verified development kit offered by the FPGA, GPU or
  ASIC vendor. Often, the design itself or
  a similar design is available as a board/
  kit by the suppliers of power products
  and FPGA, GPU and ASIC manufacturers. Using a tested and verified kit unburdens
  system designers of most power system
  and analog issues, allowing them instead
  to focus their energies on configuring the
  complex digital systems. The optimum
  power system layout is taken care of
  before significant design is undertaken. THOUGHTFUL POWER MANAGEMENT
  IS CHALLENGING AT THE START Every design task is initially daunting,
  and power management design is no
  exception. This is the case when power is …

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  4.5µA Li-Ion Battery Protection Circuit &mdash LT Journal
  PDF, 114 Kb, File published: Jun 1, 1999
  Extract from the document

  DESIGN IDEAS 4.5ВµA Li-Ion Battery Protection Circuit
  by Albert Lee Li-Ion Battery
  Undervoltage Lockout
  Figure 1 shows an ultralow power,
  precision undervoltage-lockout circuit. The circuit monitors the voltage
  of a Li-Ion battery and disconnects
  the load to protect the battery from
  deep discharge when the battery voltage drops below the lockout threshold.
  Storing a battery-powered product in
  a discharged state puts the battery at
  risk of being completely discharged.
  In a discharged condition, current to
  the protection circuitry continuously
  discharges the battery. If the battery
  is discharged below the recommended
  end-of-discharge voltage, overall battery performance degrades, the cycle
  life is shortened and the battery may
  die prematurely. In contrast, if the
  lockout voltage is set too high, maximum battery capacity is not realized.
  The low-battery mode of operation
  is indicated when, for instance, a cell
  phone automatically powers down after the battery-low indicator has been
  flashing for some time. If the phone is …

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  How to Choose a Voltage Reference &mdash LT Journal
  PDF, 282 Kb, File published: Mar 1, 2009
  Extract from the document

  L DESIGN FEATURES How to Choose a Voltage Reference
  by Brendan Whelan Why Voltage References? 5V It is an analog world. All electronic
  devices must in some way interact with
  the “real” world, whether they are in
  an automobile, microwave oven or cell
  phone. To do that, electronics must be
  able to map real world measurements
  (speed, pressure, length, temperature)
  to a measurable quantity in the electronics world (voltage). Of course, to
  measure voltage, you need a standard
  to measure against. That standard is
  a voltage reference. The question for
  any system designer is not whether he
  needs a voltage reference, but rather,
  which one?
  A voltage reference is simply that—a
  circuit or circuit element that provides
  a known potential for as long as the circuit requires it. This may be minutes,
  hours or years. If a product requires
  information about the world, such VIN 18k LTC1286
  1
  2 LT1634-4.096 0.1ВµF 3
  4 VREF VCC +IN CLK –IN DOUT GND CS/SHDN 8 5V 7 …

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Manufacturer's Classification

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