Datasheet Linear Technology LTC3649

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Design Notes

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  80ВµA Quiescent Current Synchronous Step-Down Controller Extends Battery Life in Automotive Applications &mdash DN1014
  PDF, 103 Kb, File published: Dec 18, 2006
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  advertisement 80µA Quiescent Current Synchronous Step-Down Controller Extends Battery Life in Automotive Applications – Design Note 1014
  Julian Zhu Introduction
  Battery powered applications that have a significant
  amount of time in standby mode, require electrical circuits
  to operate with a low quiescent current to preserve battery life. The LTC3835 synchronous step-down controller
  is an excellent solution with its ultralow quiescent current (80µA). Other features make it uniquely qualified to
  satisfy the needs of automotive applications. A wide 4V
  to 36V input voltage range protects the supply against
  high input voltage transients and is compatible with low
  voltage cold crank conditions. The constant frequency
  current-mode architecture with high-side inductor current sensing provides excellent line and load regulation
  and reliable current limiting and sharing. The 0.8V to
  10V output voltage range provides flexibility for a variety
  of applications. Solution size is small due to the 650kHz
  switching frequency, which reduces external component
  sizes, and the integrated synchronous FET driver, which
  keeps component count low. Furthermore, the LTC3835
  provides high efficiency over a wide load range up to 20A.
  Other important features include:
  CLKOUT The output voltage can be ramped during start-up with
  an adjustable soft-start or it can track an external ramp
  signal. The controller can be synchronized to an external clock
  via a phase-locked loop. The CLKOUT pin and current mode control allow interleaved operation of multiple parallel controllers for …

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  60V Input Monolithic Converter Powers Critical Circuits without Supercaps or Other Additional Components &mdash DN1040
  PDF, 203 Kb, File published: Nov 15, 2016
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  60V Input Monolithic Converter Powers Critical Circuits
  without Supercaps or Other Additional Components
  Design Note 1040
  Victor Khasiev
  Introduction
  The LTC3649 is a monolithic step-down regulator capable of operating from an input voltage range of 3.1V
  to 60V, and efficiently producing a (single) resistorprogrammable output voltage at up to 4A of output
  current. These features alone make it a compelling
  industrial or automotive supply for output voltages
  from (VIN – 0.5V) to ground. One unique feature of
  the LTC3649 is that it is capable of providing power
  RIB
  169k to critical systems when there is a power outage,
  without any extra components.
  Hold-up circuits supply power to critical systems when
  the main power rail fails, allowing them to perform
  important housekeeping tasks, such as data retention, for a short period before all available energy
  L, LT, LTC, LTM, Linear Technology, the Linear logo and LTspice are
  registered trademarks of Linear Technology Corporation. All other trademarks
  are the property of their respective owners. INTVCC
  D1
  PDS760
  VIN …

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  60V, 4A Synchronous Monolithic Step-Down Regulator Has Rail-to Rail Operation &mdash DN550
  PDF, 346 Kb, File published: Apr 5, 2016
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  60V, 4A Synchronous Monolithic Step-Down Regulator Has
  Rail-to Rail Operation
  Design Note 550
  Victor Khasiev
  Introduction
  The LTC3649 is a high efficiency synchronous monolithic step-down regulator, which integrates top and
  bottom N-channel MOSFETs on the die. This regulator
  features a wide input voltage range, 3.1V to 60V, and
  a wide output voltage range from 0V to (VIN -0.5V).
  This extremely wide range of operating voltages
  makes the LTC3649 especially attractive for industrial,
  medical and transportation applications, where the
  rail voltage can be less than 5V or above 40V during
  voltage transient events. The input voltage range of
  the LTC3649 also covers mass produced and widely
  accepted 12V and 24V solar panels, where it is used as
  a downstream converter in alternative energy systems.
  In contrast to the majority of DC/DC controllers and
  regulators, the output voltage of LTC3649 can be
  programmed by either a single resistor or the reference
  of its internal error amplifier. It also features a current
  monitoring output, IMON. The LTC3649’s unique comR2
  2.1k 4.7n bination of features opens up interesting applications …

Articles

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  60V Input Monolithic Converter Powers Critical Circuits without Supercaps or Other Additional Components &mdash LT Journal
  PDF, 147 Kb, File published: Jul 7, 2017
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  60V Input Monolithic Converter Powers Critical Circuits
  without Supercaps or Other Additional Components
  Victor Khasiev The LTC3649 is a monolithic step-down regulator capable of operating from an input voltage
  range of 3.1V to 60V, and efficiently producing a single resistor-programmable output voltage
  at up to 4A of output current. These features make it a compelling industrial or automotive
  supply for output voltages from (VIN – 0.5V) to ground. The LTC3649 is capable of providing
  power to critical systems when there is a power outage, without any extra components.
  Hold-up circuits supply power to critical
  systems when the main power rail fails,
  allowing them to perform important
  housekeeping tasks, such as data retention, for a short period before all available energy is lost. Typical hold-up RIB
  169k solutions employ dedicated controllers
  and large storage capacitors,1,2 where
  the additional cost and complexity is
  warranted if the critical circuits require
  significant power and hold-up time. But if
  the required hold-up energy is relatively INTVCC
  D1
  PDS760
  VIN
  5V TO 60V VOUT1
  5V VINREG
  VIN …

Model Line

Manufacturer's Classification

• Power Management > Switching Regulator > Step-Down (Buck) Regulators > Internal Power Switch Buck | High Input Voltage Buck