Datasheet Linear Technology LT1930A

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LT1930

Design Notes

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  SOT-23 Switching Regulator with Integrated 1A Switch Delivers High Current Outputs in a Small Footprint &mdash DN232
  PDF, 91 Kb, File published: Jun 1, 2001
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  advertisement SOT-23 Switching Regulator with Integrated 1A Switch Delivers
  High Current Outputs in a Small Footprint – Design Note 232
  Albert Wu 5V Local Supply
  Figure 1 shows a typical 3.3V to 5V boost converter
  using the LT1930. The circuit can provide an impressive output current of 480mA while occupying less
  than 0.3" by 0.35" of board area (less than 0.105 in2).
  The efficiency, shown in Figure 2, remains above 83%
  over a wide load current range of 60mA to 450mA,
  reaching 86% at 200mA. The maximum output voltage
  ripple of this circuit is 40mVP-P, which corresponds
  to less than 1% of the nominal 5V output. Figure 3 is
  an oscillograph of the transient response. The lower
  waveform depicts a load step from 200mA to 300mA,
  the middle waveform shows the inductor current and
  the upper waveform shows the output voltage. The
  output voltage remains within 1% of the nominal value
  during the transient steps and displays a nice damped
  response with little ringing.
  L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks
  of Linear Technology Corporation. All other trademarks are the property of their
  respective owners. 06/00/232_conv L1
  5.6ОјH VIN
  3.3V …

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  Fiber Optic Communication Systems Benefit from Tiny, Low Noise Avalanche Photodiode Bias Supply &mdash DN273
  PDF, 246 Kb, File published: Dec 1, 2001
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  Fiber Optic Communication Systems Benefit from Tiny, Low
  Noise Avalanche Photodiode Bias Supply – Design Note 273
  Michael Negrete
  Avalanche photodiodes (APDs) are the photo detectors of
  choice for long-haul fiber optic communication systems
  because of their high sensitivity and high internal gain. An
  important characteristic of APDs is that their internal gain
  is optimal when there is a high voltage reverse bias (30V
  to 90V) across the APD. Nevertheless, the high gain is all
  for naught if the sensitivity of the APD is compromised
  by a noisy bias supply. The LT1930A, a capacitor-diode tripler and an external
  DAC provide a bias voltage of up to 90V, allowing easy
  temperature compensation (via the DAC) to optimize
  internal gain. By running the IC at a switching frequency
  of 2.2MHz, one can use tiny, low cost capacitors and
  inductors to keep the circuit footprint under 0.5in2. The
  LT1930A’s constant frequency PWM operation keeps
  output noise low and easy to filter. Traditionally, such low noise bias supplies required custom circuits that brought with them another problem:
  large space requirements. Linear Technology’s LT®1930A
  2.2MHz step-up DC/DC converter in a 5-lead SOT-23
  package solves these APD bias voltage problems and
  does so in a compact package suitable for most fiber
  optic applications. Figure 1 shows a high voltage, low noise APD bias supply …

Articles

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  1.1A Boost Provides Soft-Start Capability in Tiny ThinSOT Package &mdash LT Journal
  PDF, 475 Kb, File published: Mar 25, 2005
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  DESIGN FEATURES 1.1A Boost Provides Soft-Start
  Capability in Tiny ThinSOT Package
  Introduction by Brian Adolf L1
  2.7ВµH
  C1
  4.7ВµF OFF ON C3
  0.047ВµF 4 D1 6 1 VIN SW SHDN
  LT3467
  5
  SS R1
  402k C4
  3.3pF VOUT
  5V
  765mA AT VIN = 4.2V,
  540mA AT VIN = 3.3V,
  360mA AT VIN = 2.6V 3 FB R2
  133k GND
  2 C2
  15ВµF C1, C2: X5R OR X7R, 6.3V
  D1: ON SEMICONDUCTOR MBRM120
  L1: SUMIDA CR43-2R7 95
  90
  VIN = 4.2V 85 …

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  SOT-23 Switching Regulator with Integrated 1 Amp Switch Delivers High Current Outputs &mdash LT Journal
  PDF, 259 Kb, File published: May 1, 2000
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  DESIGN FEATURES SOT-23 Switching Regulator with
  Integrated 1 Amp Switch Delivers
  High Current Outputs
  by Albert Wu
  The LT1930 is the only SOT-23
  switching regulator in the industry
  that includes an integrated 1A switch.
  The LT1930 utilizes a constant frequency, internally compensated,
  current mode PWM architecture. Its
  1.2MHz switching frequency allows
  the use of tiny, low cost capacitors
  and low profile inductors. With an
  input voltage range of 2.6V to 16V,
  the LT1930 is a good fit for a variety of
  applications. The onboard switch features a low VCESAT voltage of 400mV at
  1A, resulting in very good efficiency
  even at high load currents.
  Figure 1 shows a typical 3.3V to 5V
  boost converter using the LT1930. The circuit can provide an impressive
  output current of 480mA. The efficiency remains above 83% over a
  wide load current range of 60mA to
  450mA, reaching 86% at 200mA. The
  maximum output voltage ripple of …

Model Line

Manufacturer's Classification

• Power Management > Switching Regulator > LCD/CCD/OLED Bias | SEPIC Regulators
• Power Management > Switching Regulator > Step-Up (Boost) Regulators > Internal Power Switch Boost