Datasheet Linear Technology LTC3803

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  Triple-Output Telecom Housekeeping Converter Small Enough for a Postage Stamp Board &mdash LT Journal
  PDF, 82 Kb, File published: Feb 1, 2004
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  DESIGN IDEAS Triple-Output Telecom Housekeeping
  Converter Small Enough for a Postage
  by Goran Perica
  Stamp Board
  Many telecom applications require a
  small DC/DC converter that can deliver a few watts of output power to
  housekeeping circuitry. Small size and
  high efficiency are primary concerns in
  any converter design because telecom
  system boards are densely packed with
  circuitry. The problem is that these
  two requirements are often at odds in
  a DC/DC converter. A high switching
  frequency minimizes the size of the
  transformer and filter capacitors, but a
  low switching frequency keeps switching loses low, and efficiency high.
  The converter shown in Figure 1
  solves this problem by operating at
  200kHz, which is high enough to keep
  the circuit small, but sufficiently low
  to keep efficiency high. The control
  DESIGN IDEAS
  Triple-Output Telecom Housekeeping …

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  Simple, Fast Pulse Source Outpaces Expensive Lab Equipment &mdash LT Journal
  PDF, 91 Kb, File published: Aug 11, 2016
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  design ideas Simple, Fast Pulse Source Outpaces Expensive Lab
  Equipment
  Mitchell Lee A source of fast pulse edges, simulating a step function, is often useful in making lab
  measurements of one kind or another. For example, it is possible to evaluate the rise
  time of RG-58/U or other coaxial cables using lengths of only 10 to 20 feet if an edge
  rate on the order of 1ns–2ns is available. The ubiquitous HP8012B pulse generator,
  a workhorse in many labs, falls short at 5ns, and is not quite fast enough for the
  task at hand. The gate drive output rise and fall times of certain switching regulator
  controllers are faster than 2ns, making such devices potentially ideal pulse sources.
  Figure 1 shows a simple implementation
  using an LTC3803 constant frequency
  flyback controller. The controller selfclocks at 200kHz; applying a sample
  of the output to the SENSE pin causes
  the device to operate at its minimum
  duty cycle, producing a 300ns output
  pulse width. Supply bypassing is important, as the output delivers upwards
  of 180m A into a 50О© load. The 10Вµ F
  bypass and 200О© decoupling components minimize pulse top aberration
  without compromising droop. prime importance, back termination (as
  shown) is recommended to suppress triple
  transit echos by absorbing reflections from
  cabling and the far-end termination. Back
  termination is also useful when driving …

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Manufacturer's Classification

• Power Management > Switching Regulator > Flyback, Forward and Isolated Controllers
• Space & Harsh Environment > Extended Temperature Plastic (H & MP) > Extended Temperature (H & MP) Switching Regulators