LTC7815 - Low IQ, 2.25MHz, Triple Output, Buck/Buck/Boost Synchronous Controller


  • Dual Buck Plus Single Boost Synchronous Controllers
  • Wide Bias Input Voltage Range: 4.5V to 38V
  • Outputs Remain in Regulation Through Cold Crank Down to a 2.5V Input Supply Voltage
  • Buck Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
  • Boost Output Voltage Up to 60V
  • Low Operating IQ: 28μA (One Channel On)
  • RSENSE or DCR Current Sensing
  • 100% Duty Cycle for Boost Synchronous MOSFET Even in Burst Mode® Operation
  • Phase-Lockable Frequency (320kHz to 2.25MHz)
  • Programmable Fixed Frequency (320kHz to 2.25MHz)
  • Very Low Buck Dropout Operation: 98% Duty Cycle
  • Small 38-Lead 5mm × 7mm QFN Package

Typical Application

LTC7815 Typical Application
LTC7815 Typical Application


The LTC®7815 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 2.25MHz. The LTC7815 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 LTC7815 can operate from an input supply as low as 2.5V after start-up.

The 28μA 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 LTC7815 features a precision 0.8V reference for the bucks, 1.2V reference for the boost and a power good output indicator. The PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.


For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC7815EUHF#PBF 5x7 QFN-38 UHF E 05-08-1701 Yes
LTC7815EUHF#TRPBF 5x7 QFN-38 UHF E 05-08-1701 Yes
LTC7815HUHF#PBF 5x7 QFN-38 UHF H 05-08-1701 Yes
LTC7815HUHF#TRPBF 5x7 QFN-38 UHF H 05-08-1701 Yes
LTC7815IUHF#PBF 5x7 QFN-38 UHF I 05-08-1701 Yes
LTC7815IUHF#TRPBF 5x7 QFN-38 UHF I 05-08-1701 Yes

LTC7815 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LTC7815EUHF#PBF 5x7 QFN-38 E $6.22 $4.35 Yes
LTC7815EUHF#TRPBF 5x7 QFN-38 E $6.28 $4.41 Yes
LTC7815HUHF#PBF 5x7 QFN-38 H $7.40 $5.18 Yes
LTC7815HUHF#TRPBF 5x7 QFN-38 H $7.46 $5.24 Yes
LTC7815IUHF#PBF 5x7 QFN-38 I $6.97 $4.88 Yes
LTC7815IUHF#TRPBF 5x7 QFN-38 I $7.03 $4.94 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC2738A LTC7815EUHF Demo Board | 4.5V ≤ VIN ≤ 36V; VOUT1: 5V @ 8A, VOUT2: 3.3V @ 8A, VOUT3: 10V @ 7A Contact Factory
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  • Automotive Always-On and Start-Stop Systems
  • Battery Operated Digital Devices
  • Distributed DC Power Systems
  • Multioutput Buck-Boost Applications

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

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