Datasheet Linear Technology LT8614

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Application Notes

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  Reduce EMI and Improve Efficiency with Silent Switcher Designs &mdash AN144
  PDF, 159 Kb, File published: Dec 19, 2013
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  Application Note 144
  November 2013
  Reduce EMI and Improve Efficiency with
  Silent Switcher Designs
  Christian Kueck
  Switching regulators replace linear regulators in areas
  where low heat dissipation and efficiency are valued. The
  switching regulator is typically the first active component
  on the input power bus line, and therefore has a significant
  impact on the EMI performance of the complete converter
  circuit.
  Modern input filter components in surface mount technology have better performance than through-hole parts.
  However, this improvement is outpaced by the increase in
  operating switching frequencies of switching regulators.
  Higher efficiency, low minimum on-and off-times result in
  higher harmonic content due to the faster switch transitions.
  For every doubling in switching frequency the EMI becomes
  6dB worse when all other parameters, such as switch capacity and transition times, remain constant. The wideband
  EMI behaves like a first order highpass with 20dB higher
  emissions if the switching frequency increases by 10Г—.
  Savvy PCB designers will make the hot loops small and
  use shielding GND layers as close to the active layer as possible; nevertheless pinout, package construction,
  thermal design requirements and package sizes needed …

Articles

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  Silent Switcher Meets CISPR Class 5 Radiated Emissions While Maintaining High Conversion Efficiency &mdash LT Journal
  PDF, 276 Kb, File published: Jan 6, 2014
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  design features Silent Switcher Meets CISPR Class 5 Radiated Emissions
  While Maintaining High Conversion Efficiency
  Tony Armstrong & Christian KГјck When minimizing EMI is a design priority, a linear regulator can be a low noise solution,
  but heat dissipation and efficiency requirements may preclude that choice and point to a
  switching regulator. Even in EMI-sensitive applications, a switching regulator is typically
  the first active component on the input power bus line, and regardless of downstream
  converters, it significantly impacts overall converter EMI performance. Until now, there was
  no sure way to guarantee that EMI could be suppressed and efficiency requirements attained
  via power IC selection. The LT8614 Silent Switcherв„ў regulator now makes this possible.
  The LT8614 reduces EMI by more than
  20dB compared to current state-of-the-art
  switching regulators. In comparison, it
  lowers EMI by 10x in the frequency range
  above 30MHz without compromising
  minimum on-and off-times or efficiency in
  an equivalent board area. It accomplishes
  this with no additional components or
  shielding, representing a significant breakthrough in switching regulator design.
  A NEW SOLUTION TO EMI ISSUES The tried and true solution to EMI issues
  is to use a shielding box for the complete
  circuit. Of course, this adds a significant costs in required board space, components and assembly, while complicating thermal management and testing.
  Another method is to slow down the
  switching edges. This has the undesired …

Model Line

Manufacturer's Classification

• Power Management > Switching Regulator > Ultralow Noise Regulators
• Power Management > Switching Regulator > Step-Down (Buck) Regulators > Micropower Buck Regulators | Internal Power Switch Buck | High Input Voltage Buck
• Space & Harsh Environment > Extended Temperature Plastic (H & MP) > Extended Temperature (H & MP) Switching Regulators