Analog Devices LTC7812

Description

Boost+Buck DC/DC switching regulator controller thatdrives all N-channel power MOSFET stages. It containsindependent step-up (boost) and step-down (buck) controllersthat can regulate two separate outputs or be cascadedto regulate an output voltage from an input voltage thatcan be above, below, or equal to the output voltage. TheLTC7812 operates from a wide 4.5V to 38V input supplyrange. When biased from the output of the boost regulator,the LTC7812 can operate from an input supply as low as2.5V after start-up. The 33μA no-load quiescent currentextends operating run time in battery-powered systems.Unlike conventional buck-boost regulators, the LTC7812’scascaded Boost+Buck solution has continuous, nonpulsating,input and output currents, substantially reducingvoltage ripple and EMI. The LTC7812 has independentfeedback and compensation points for the boost and buckregulation loops, enabling a fast output transient responsethat can be easily optimized externally.

Features

Synchronous Boost and Buck ControllersWhen Cascaded, Allows VIN Above, Below, or Equal to Regulated VOUTOutput Remains in Regulation Through Input Dips (e.g., Cold Crank) Down to 2.5VWide Bias Input Voltage Range: 4.5V to 38VLow Input and Output RippleLow EMIFast Output Transient ResponseHigh Light Load EfficiencyLow Operating IQ: 33μA (Both Channels On)Low Operating IQ: 28μA (Buck Channel On)RSENSE or Lossless DCR Current SensingBuck Output Voltage Range: 0.8V ≤ VOUT ≤ 24VBoost Output Voltage Up to 60VPhase-Lockable Frequency (75kHz to 850kHz)Small 32-Pin 5mm × 5mm QFN Package

Typical applications

• High Power Battery Operated Systems
• Automotive and Industrial Power Systems

More information

• Datasheet
• IC product information