Datasheet Linear Technology LT1932ES6#PBF — Datenblatt

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  High Efficiency White LED Driver Guarantees Matching LED Brightness &mdash DN267
  PDF, 80 Kb, Datei veröffentlicht: Sep 2, 2001
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  High Efficiency White LED Driver Guarantees Matching LED
  Brightness – Design Note 267
  Dave Kim
  Introduction
  White LEDs are widely used in small LCD backlight
  applications for simplicity, high reliability and low cost.
  However, due to variations in the forward voltage drop of
  white LEDs, matching the brightness becomes a major
  design consideration for multiple LED applications.
  Since LED brightness is proportional to current rather
  than voltage, a constant-current source driving LEDs in
  series should be used to ensure the same illumination
  of each LED. The LTВ®1932 uses a constant-current stepup architecture that directly regulates the LED current
  and guarantees a constant light intensity in each LED,
  regardless of differences in their forward voltage drops.
  Its unique internal current source accurately regulates
  LED current even when the input voltage is higher than
  the LED voltage, greatly simplifying the battery/adapter
  power designs. The internal 36V switch is capable of
  driving up to eight LEDs in series with 20mA of LED
  current. Li-Ion LED Driver for Four White LEDs
  The white LED driver shown in Figure 1 is an ideal solution for Li-Ion powered, 4-LED backlight applications.
  The LT1932 and п¬Ѓve external components require less …

Artikel

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  Constant-Current DC/DC Converter Drives White LEDs with 80% Efficiency &mdash LT Journal
  PDF, 140 Kb, Datei veröffentlicht: May 1, 2001
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  DESIGN FEATURES Constant-Current DC/DC Converter
  Drives White LEDs with 80% Efficiency
  by Bryan Legates
  Introduction
  flow in the LEDs, leading to brightness
  mismatch. Typical efficiencies of 75%
  to 80% are obtained using the LT1932,
  significantly higher than the 40% to
  50% efficiencies obtained in paralleldriven charge-pump solutions.
  A single external resistor sets the
  LED current between 5mA and 40mA,
  which can then be easily adjusted to
  provide dimming using either a DC
  voltage or a pulse-width-modulated
  (PWM) signal. With an input voltage
  range of 1V to 10V, the LT1932 works
  from a variety of input sources; it can
  even regulate the LED current when
  the input voltage is higher than the The new LT1932 DC/DC converter is
  specifically designed to provide high
  efficiency, constant-current drive for
  white LED backlights. To achieve the
  best possible brightness matching, …

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• Power Management > LED Driver ICs > Step-Up (Boost) LED Drivers

Andere Namen:

LT1932ES6PBF, LT1932ES6 PBF