FEATURES
nn Ultralow Quiescent Current nn 2.5µA IQ at 12VIN to 3.3VOUT
nn Low Ripple Burst Mode® Operation nn Output Rip...
FEATURES
nn Ultralow Quiescent Current nn 2.5µA IQ at 12VIN to 3.3VOUT
nn Low Ripple Burst Mode® Operation nn Output Ripple < 10mVP-P
nn Wide Input Voltage Range: 4.2V to 42V Operating nn Adjustable Switching Frequency: 200kHz to 2.2MHz nn Integrated Boost and Catch Diodes nn 750mA Output Current nn Excellent Start-Up and Dropout Performance nn Fixed Output Voltages: 3.3V, 5V
nn 1.9µA IQ at 12VIN nn Accurate Programmable Undervoltage Lockout nn Low Shutdown Current: IQ = 0.75µA nn Internal Catch Diode Current Limit nn Power Good Flag nn Thermal Shutdown nn Small, Thermally Enhanced 10-Lead MSOP and
(3mm × 3mm) DFN Packages
APPLICATIONS
nn Automotive Battery Regulation nn Power for Portable Products nn Industrial Supplies nn Gate Drive Bias
LT3973/LT3973-3.3/LT3973-5 42V, 750mA Step-Down
Regulator with 2.5µA Quiescent Current and Integrated Diodes
DESCRIPTION
The LT®3973 is an adjustable frequency monolithic buck switching
regulator that accepts a wide input voltage range up to 42V, and consumes only 2.5µA of quiescent current. A high efficiency switch is included on the die along with the catch diode, boost diode, and the necessary oscillator, control and logic circuitry. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping the output ripple below 10mV in a typical application. A minimum dropout voltage of 530mV is maintained when the input voltage drops below the programmed output voltage, such as during automotive cold crank. Curre...