Datasheet Linear Technology LTC7820

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Design Notes

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  High Efficiency, High Density, Switched Capacitor Converter Suitable for High Power Applications &mdash DN1043
  PDF, 360 Kb, File published: Jun 8, 2017
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  High Efficiency, High Density, Switched Capacitor
  Converter Suitable for High Power Applications
  Design Note 1043
  By Jian Li, Jeff Zhang, Ya Liu, and Marvin Macairan
  Introduction
  The power density of a DC/DC converter is generally
  limited by bulky magnetic components, especially in
  applications where the input and output voltages are
  relatively high. One way to reduce inductor/transformer size is to increase the switching frequency,
  but this reduces converter efficiency because of
  switching-related losses.
  Another way to increase power density is to use an
  inductorless switched capacitor converter (charge
  pump) topology. Charge pumps can increase power
  density as much as 10X over a conventional converter
  without sacrificing efficiency. Instead of an inductor,
  a “flying capacitor” is used to store and transfer the
  energy from input to output. Despite the advantages
  of a charge pump design, switched capacitor converters have been limited to low power applications, due to the challenges presented in start-up, protection,
  gate drive and regulation.
  The LTC7820 is a fixed ratio, high voltage, high power
  switched capacitor controller that yields small and
  cost effective solutions for high power, nonisolated …

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  170W Voltage Doubler in 23mm x 16.5mm Package &mdash DN571
  PDF, 525 Kb, File published: Jan 17, 2018
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  Design Note
  170W Voltage Doubler in 23mm Г— 16.5mm Package
  Ya Liu, Jian Li, Jeff Zhang and Brian Lin
  Introduction
  For high voltage input/output applications, inductorless,
  switched capacitor converters (charge pumps) significantly
  improve efficiency and reduce solution size over
  conventional inductor-based buck or boost topologies.
  By using a charge pump instead of an inductor, a “flying
  capacitor” is used to store and transfer the energy from
  input to output. The energy density of capacitors is much
  higher than inductors, improving power density by a factor
  of 10 using a charge pump. However, charge pumps have
  traditionally been limited to low power applications, due
  to the challenges presented in start-up, protection, gate
  drive and regulation.
  The LTC В®7820 overcomes these problems, allowing high
  power density, high efficiency (to 99%) solutions. This
  fixed-ratio high voltage, high power switched capacitor controller includes four N-channel MOSFET gate drivers,
  for use with external power MOSFETs, to produce a voltage
  divider, doubler, or inverter: specifically, 2:1 step-down
  from inputs to 72V, 1:2 step-up from input voltages to
  36V, or a 1:1 inverter from inputs to 36V. Each power …

Articles

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  High Efficiency, High Density, Switched Capacitor Converter for High Power Applications &mdash LT Journal
  PDF, 625 Kb, File published: Jul 7, 2017
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  design features High Efficiency, High Density, Switched Capacitor Converter
  for High Power Applications
  Jian Li, Jeff Zhang, Ya Liu, and Marvin Macairan The power density of a DC/DC converter is generally limited by bulky magnetic components,
  especially in applications where the input and output voltages are relatively high. Inductor/
  transformer size can be reduced by increasing the switching frequency, but this reduces
  converter efficiency because of switching-related losses. Better, eliminate the magnetics
  altogether with an inductorless switched capacitor converter (charge pump) topology.
  Charge pumps can increase power density as much as 10Г— over a conventional
  converter without sacrificing efficiency. Instead of an inductor, a “flying capacitor” stores
  and transfers the energy from input to output. Despite the advantages of charge pump
  designs, switched capacitor converters are traditionally limited to low power applications,
  due to the challenges presented in start-up, protection, gate drive and regulation.
  The LTCВ®7820 is a fixed ratio, high
  voltage, high power switched capacitor
  controller that yields small and cost-effective solutions for high power, nonisolated
  intermediate bus applications with fault
  protection. The LTC780’s features include: Low profile, high power density, capable
  of 500W+ Soft switching: 99% peak efficiency and
  low EMI VIN max for voltage divider (2:1): 72V Soft start-up into steady state operation VIN max for voltage doubler (1:2)/
  inverter (1:1): 36V Input current sensing and overcurrent
  protection Wide bias VCC range: 6V to 72V Integrated gate drivers Output short-circuit/OV/UV protection
  with programmable timer and retry Figure 1. A 48V to 24V/20A voltage divider with a power density of 4000W/in3
  10О© …

Model Line

Manufacturer's Classification

• Power Management > Inductorless (Charge Pump) DC/DC Converters > Unregulated Doubling/Inverting Charge Pumps | High Voltage Charge Pumps