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  Boost-then-Buck LED Drivers Enable Wide PWM Dimming Range with Wide-Ranging Input Voltages (LT3797) &mdash LT Journal
  PDF, 218 Kb, Datei veröffentlicht: Apr 9, 2014
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  Boost-then‑Buck LED Drivers Enable Wide PWM Dimming
  Range with Wide-Ranging Input Voltages
  Keith Szolusha and Taffy Wong Multichannel LED drivers are primarily designed to power
  multiple LEDs or multiple LED strings, sometimes of different
  colors or lengths, from a single IC. These drivers, however,
  include a number of features that allow for other compelling
  uses. The LT3797 3-channel LED driver, for instance, can
  be configured to produce boost-then-buck capability with
  one channel as a boost voltage preregulator while the other
  two channels are configured as buck mode LED drivers.
  When the input voltage source is wideranging and can be both above and below
  the LED string rating, a buck-boost or
  SEPIC topology is commonly used. These compared to buck-only converters, and
  lower efficiency and higher conducted
  EMI compared to boost-only regulators.
  One way to avoid these problems is to
  boost a wide-ranging input with a voltage preregulator and use that as the input
  to a buck-only LED driver. This has the
  advantages of step-up and step-down,
  high PWM dimming bandwidth, and
  lower conducted EMI. Since the LT3797
  has three channels that can be used
  for either voltage regulation or driving …

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Herstellerklassifikation

• Power Management > LED Driver ICs > Buck-Boost LED Drivers | Multitopology LED Driver | Step-Up (Boost) LED Drivers | Step-Down (Buck) LED Drivers

Andere Namen:

LT3797EUKGTRPBF, LT3797EUKG TRPBF