Datasheet Linear Technology LT3045IDD#PBF

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Application Notes

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  Measuring 2nV/в€љHz Noise and 120dB Supply Rejection on Linear Regulators &mdash AN159
  PDF, 1.1 Mb, File published: Feb 2, 2016
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  Application Note 159
  February, 2016
  Measuring 2nV/в€љHz Noise and 120dB Supply Rejection
  on Linear Regulators
  The Quest for Quiet
  Todd Owen and Amit Patel
  Introduction MEASURING OUTPUT VOLTAGE NOISE A quiet, well regulated supply is important for optimum
  performance with a number of circuit applications. Voltage controlled oscillators (VCOs) and precision voltage
  controlled crystal oscillators (VCXOs) respond to small
  changes in their supply very quickly. Phase-locked loops
  (PLLs) require a stable supply as signal on the supply
  translates directly to phase noise in the output. RF amplifiers require quiet supplies as they have little to no ability
  to reject supply variations and regulator variation will
  appear as unwanted side bands and lower the signal-tonoise ratio. Low noise amplifiers and analog-to-digital
  converters (ADCs) do not have infinite supply rejection
  and the cleaner the regulator output is, the higher their
  performance. These are just a few applications where linear
  regulators are required to provide quiet power supply rails,
  but how does one ensure that the regulator is performing
  as advertised? Being Quiet is Nothing New Once fully built, one can determine if the supply being
  used has low enough noise for the application. Oscillator
  phase noise is measured and compared against results
  achieved with a known good supply, ADCs are checked …

Articles

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  Industry's First 0.8µVRMS Noise LDO Has 79dB Power Supply Rejection Ratio at 1MHz &mdash LT Journal
  PDF, 1.1 Mb, File published: Apr 7, 2015
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  April 2015 I N T H I S I S S U E patent-pending boost-buck
  LED driver topology 8 I2C programmable
  supervisors with EEPROM
  12 Volume 25 Number 1 Industry’s First 0.8µVRMS Noise
  LDO Has 79dB Power Supply
  Rejection Ratio at 1MHz
  Amit Patel 18V buck-boost converter
  with intelligent PowerPath
  control delivers >2A 16 advantages of 75W boost
  mode LED driver 22 how to design an isolated,
  high frequency, push-pull
  DC/DC converter 25 When it comes to powering noise-sensitive analog/RF applications,
  low dropout (LDO) linear regulators are generally preferred over their
  switching counterparts. Low noise LDOs power a wide range of
  analog/RF designs, including frequency synthesizers (PLLs/VCOs),
  RF mixers and modulators, high speed and high resolution data
  converters (ADCs and DACs) and precision sensors. Nevertheless,
  these applications have reached capabilities and sensitivities
  that are testing the limits of conventional low noise LDOs.
  For instance, in many high end VCOs, power supply noise
  directly affects the VCO output phase noise (jitter). Moreover,
  to meet overall system efficiency requirements, the LDO
  usually post-regulates the output of a relatively noisy …

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Manufacturer's Classification

• Power Management > LDO Linear Regulators > Positive Linear Regulators (LDO)

Other Names:

LT3045IDDPBF, LT3045IDD PBF