LTC3859
Info : RECOMMENDED FOR NEW DESIGNS
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LTC3859

Low IQ, Triple Output, Buck/Buck/Boost Synchronous Controller

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Info : RECOMMENDED FOR NEW DESIGNS tooltip
Info : RECOMMENDED FOR NEW DESIGNS tooltip
Part Details
Part Models 8
1ku List Price Starting From $5.19
Features
  • Dual Buck Plus Single Boost Synchronous Controllers
  • Outputs Remain in Regulation Through Cold Crank Down to 2.5V
  • Low Operating IQ: 55μA (One Channel On)
  • Wide Bias Input Voltage Range: 4.5V to 38V
  • Buck Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
  • Boost Output Voltage Up to 60V
  • RSENSE or DCR Current Sensing
  • 100% Duty Cycle for Boost Synchronous MOSFET
  • Phase-Lockable Frequency (75kHz to 850kHz)
  • Programmable Fixed Frequency (50kHz to 900kHz)
  • Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Loads
  • Very Low Buck Dropout Operation: 99% Duty Cycle
  • Adjustable Output Voltage Soft-Start or Tracking
  • Low Shutdown IQ: 14μA
  • Small 38-Pin 5mm × 7mm QFN and TSSOP Packages
Additional Details
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The LTC3859 is a high performance triple output (buck/ buck/boost) synchronous DC/DC switching regulator controller that drives all N-channel power MOSFET stages. Constant frequency current mode architecture allows a phase-lockable switching frequency of up to 850kHz. The LTC3859 operates from a wide 4.5V to 38V input supply range. When biased from the output of the boost converter or another auxiliary supply, the LTC3859 can operate from an input supply as low as 2.5V after start-up.

The 55μA no-load quiescent current extends operating runtime in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC3859 features a precision 0.8V reference for the bucks, 1.2V reference for the boost and a power good output indicator.

Independent TRACK/SS pins for each controller ramp the output voltages during start-up. Current foldback limits MOSFET heat dissipation during short-circuit conditions. The PLLIN/ MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.

Quiescent Current (Burst Mode) Notes
LTC3859AL 28μA-One channel on, Buck
38μA-All three channels on
Internal clamp on the INTVCC pin
LTC3859A 55μA-One channel on, Buck
80μA-All three channels on
Internal clamp on the INTVCC pin. For new designs, we recommend LTC3859AL
LTC3859 55μA-One channel on, Buck
80μA-All three channels on
For new designs, we recommend LTC3859AL

Applications

  • Automotive Always-On and Start-Stop Systems 
  • Battery Operated Digital Devices
  • Distributed DC Power Systems
Part Models 8
1ku List Price Starting From $5.19

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Documentation

Documentation

Part Model Pin/Package Drawing Documentation CAD Symbols, Footprints, and 3D Models
LTC3859EFE#PBF
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LTC3859EUHF#TRPBF
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LTC3859IUHF#PBF
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Product Lifecycle

PCN

Apr 6, 2022

- 22_0068

Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL

LTC3859EFE#PBF

PRODUCTION

LTC3859EFE#TRPBF

PRODUCTION

LTC3859IFE#PBF

PRODUCTION

LTC3859IFE#TRPBF

PRODUCTION

Jul 31, 2020

- 20_0245

Notification of Wafer Fab Location Change for 0.6µm BICMOS Process Devices from ADI Milpitas (Hillview) to Vanguard Int. (Taiwan)

LTC3859EFE#PBF

PRODUCTION

LTC3859EFE#TRPBF

PRODUCTION

LTC3859EUHF#PBF

PRODUCTION

LTC3859EUHF#TRPBF

PRODUCTION

LTC3859IFE#PBF

PRODUCTION

LTC3859IFE#TRPBF

PRODUCTION

LTC3859IUHF#PBF

PRODUCTION

LTC3859IUHF#TRPBF

PRODUCTION

Filter by Model

reset

Reset Filters

Part Models

Product Lifecycle

PCN

Apr 6, 2022

- 22_0068

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Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL

LTC3859EFE#PBF

PRODUCTION

LTC3859EFE#TRPBF

PRODUCTION

LTC3859IFE#PBF

PRODUCTION

LTC3859IFE#TRPBF

PRODUCTION

Jul 31, 2020

- 20_0245

arrow down

Notification of Wafer Fab Location Change for 0.6µm BICMOS Process Devices from ADI Milpitas (Hillview) to Vanguard Int. (Taiwan)

LTC3859EFE#PBF

PRODUCTION

LTC3859EFE#TRPBF

PRODUCTION

LTC3859EUHF#PBF

PRODUCTION

LTC3859EUHF#TRPBF

PRODUCTION

LTC3859IFE#PBF

PRODUCTION

LTC3859IFE#TRPBF

PRODUCTION

LTC3859IUHF#PBF

PRODUCTION

LTC3859IUHF#TRPBF

PRODUCTION

Software & Part Ecosystem

Software & Part Ecosystem

Tools & Simulations

Tools & Simulations 1

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

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