DESCRIPTION
The LT®3975 is an adjustable frequency monolithic buck switching regulator that accepts a wide input voltage range up to 42V. Low quiescent current design consumes only 2.7µA of supply current while regulating with no load. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping the output ripple below 15mV in a typical application. The LT3975 can supply up to 2.5A of load current and has current limit foldback to limit power dissipation during short circuit. A low dropout voltage of 500mV is maintained when the input voltage drops below the programmed output voltage, such as during automotive cold crank.

FEATURES
■ Ultralow Quiescent Current: 2.7µA IQ at 12VIN to 3.3VOUT
■ Low Ripple Burst Mode® Operation Output Ripple < 15mVP-P
■ Wide Input Range: Operation from 4.3V to 42V
■ 2.5A Maximum Output Current
■ Excellent Start-Up and Dropout Performance
■ Adjustable Switching Frequency: 200kHz to 2MHz
■ Synchronizable Between 250kHz to 2MHz
■ Accurate Programmable Undervoltage Lockout
■ Low Shutdown Current: IQ = 700nA
■ Power Good Flag
■ Soft-Start Capability
■ Thermal Shutdown Protection
■ Current Limit Foldback with Soft-Start Override
■ Saturating Switch Design: 75mΩ On Resistance
■ Small, Thermally Enhanced 16-Lead MSOP Package

APPLICATIONS
■ Automotive Battery Regulation
■ Portable Products
■ Industrial Supplies