LTC7812 - Low IQ, 38V Synchronous Boost+Buck Controller

The LTC®7812 is a high performance synchronous Boost+Buck DC/DC switching regulator controller that drives all N-channel power MOSFET stages. It contains independent step-up (boost) and step-down (buck) controllers that can regulate two separate outputs or be cascaded to regulate an output voltage from an input voltage that can be above, below or equal to the output voltage. The LTC7812 operates from a wide 4.5V to 38V input supply range. When biased from the output of the boost regulator, the LTC7812 can operate from an input supply as low as 2.5V after start-up. The 33μA no-load quiescent current extends operating run time in battery-powered systems.

Unlike conventional buck-boost regulators, the LTC7812’s cascaded Boost+Buck solution has continuous, nonpulsating, input and output currents, substantially reducing voltage ripple and EMI. The LTC7812 has independent feedback and compensation points for the boost and buck regulation loops, enabling a fast output transient response that can be easily optimized externally.

Features
  • Synchronous Boost and Buck Controllers
  • When Cascaded, Allows VIN Above, Below or Equal to Regulated VOUT
  • Output Remains in Regulation Through Input Dips (e.g., Cold Crank) Down to 2.5V
  • Wide Bias Input Voltage Range: 4.5V to 38V
  • Low Input and Output Ripple
  • Low EMI
  • Fast Output Transient Response
  • High Light Load Efficiency
  • Low Operating IQ: 33μA (Both Channels On)
  • Low Operating IQ: 28μA (Buck Channel On)
  • RSENSE or Lossless DCR Current Sensing
  • Buck Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
  • Boost Output Voltage Up to 60V
  • Phase-Lockable Frequency (75kHz to 850kHz)
  • Small 32-Pin 5mm × 5mm QFN Package
Typical Application
LTC7812 Typical Application
Applications
  • Automotive and Industrial Power Systems
  • High Power Battery Operated Systems
Packaging
LTC7812 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC7812EUH#PBF5x5 QFN-32E$5.71$4.00
LTC7812EUH#TRPBF5x5 QFN-32E$4.06
LTC7812HUH#PBF5x5 QFN-32H$6.56$4.59
LTC7812HUH#TRPBF5x5 QFN-32H$4.65
LTC7812IUH#PBF5x5 QFN-32I$6.13$4.29
LTC7812IUH#TRPBF5x5 QFN-32I$4.35
Demo Boards
Part NumberDescriptionPrice
DC2422A-ALTC7812EUH Demo Board | Sync Buck + Sync Boost, 4V ≤ VIN ≤ 36V; VOUT = 12V @ 8A$200.00
DC2422A-BLTC7812EUH Demo Board | Sync Boost + Sync Buck, 4V ≤ VIN ≤ 36V; VOUT1 (Quasi Regulated) = 10V-16V @ 6-8A$200.00
DC2422A-CLTC7812EUH Demo Board | Sync Boost + Sync Buck, 4V ≤ VIN ≤ 36V; VBoost = 12V, Vbuck = 12V to 5V @ 8A$150.00
Datasheet
Press Release
CAD Symbol
LTpowerCAD
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LTC7812 Footprints and Symbols
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