LT3973 Series

42V, 750mA Step-Down Regulator with 2.5μA Quiescent Current and Integrated Diodes

Catalog

42V, 750mA Step-Down Regulator with 2.5μA Quiescent Current and Integrated Diodes

Part	Current - Output	Function	Voltage - Output (Max)	Output Type	Voltage - Input (Max) [Max]	Package / Case	Operating Temperature [Min]	Operating Temperature [Max]	Supplier Device Package	Number of Outputs	Topology	Voltage - Output (Min/Fixed)	Output Configuration	Frequency - Switching [Min]	Frequency - Switching [Max]	Voltage - Input (Min) [Min]	Mounting Type	Output Type	Package / Case
Analog Devices LT3973IDD#TRPBF	750 mA	Step-Down	24 V	Adjustable	42 V	10-WFDFN Exposed Pad	-40 °C	125 ¯C	10-DFN (3x3)	1	Buck	1.21 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount
Analog Devices LT3973HDD-5#TRPBF	750 mA	Step-Down			42 V	10-WFDFN Exposed Pad	-40 °C	150 °C	10-DFN (3x3)	1	Buck	5 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount	1.81 mOhm
Analog Devices LT3973HMSE#PBF	750 mA	Step-Down	24 V	Adjustable	42 V	10-MSOP 10-TFSOP Exposed Pad	-40 °C	150 °C	10-MSOP-EP	1	Buck	1.21 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount		0.118 in 3 Lead
Analog Devices LT3973EMSE#PBF	750 mA	Step-Down	24 V	Adjustable	42 V	10-MSOP 10-TFSOP Exposed Pad	-40 °C	125 ¯C	10-MSOP-EP	1	Buck	1.21 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount		0.118 in 3 Lead
Analog Devices LT3973IMSE-3.3#PBF	750 mA	Step-Down			42 V	10-MSOP 10-TFSOP Exposed Pad	-40 °C	125 ¯C	10-MSOP-EP	1	Buck	3.3 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount	1.81 mOhm	0.118 in 3 Lead
Analog Devices LT3973IDD#PBF	750 mA	Step-Down	24 V	Adjustable	42 V	10-WFDFN Exposed Pad	-40 °C	125 ¯C	10-DFN (3x3)	1	Buck	1.21 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount
Analog Devices LT3973EMSE-5#TRPBF	750 mA	Step-Down			42 V	10-MSOP 10-TFSOP Exposed Pad	-40 °C	125 ¯C	10-MSOP-EP	1	Buck	5 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount	1.81 mOhm	0.118 in 3 Lead
Analog Devices LT3973IMSE-3.3#TRPBF	750 mA	Step-Down			42 V	10-MSOP 10-TFSOP Exposed Pad	-40 °C	125 ¯C	10-MSOP-EP	1	Buck	3.3 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount	1.81 mOhm	0.118 in 3 Lead
Analog Devices LT3973HMSE-3.3#PBF	750 mA	Step-Down			42 V	10-MSOP 10-TFSOP Exposed Pad	-40 °C	150 °C	10-MSOP-EP	1	Buck	3.3 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount	1.81 mOhm	0.118 in 3 Lead
Analog Devices LT3973EDD#TRPBF	750 mA	Step-Down	24 V	Adjustable	42 V	10-WFDFN Exposed Pad	-40 °C	125 ¯C	10-DFN (3x3)	1	Buck	1.21 V	Positive	195 kHz	2.15 MHz	4.2 V	Surface Mount

Catalog

42V, 750mA Step-Down Regulator with 2.5μA Quiescent Current and Integrated Diodes

Key Features

• Ultralow Quiescent Current2.5μA IQat 12VINto 3.3VOUT

• Low Ripple Burst Mode®OperationOutput Ripple < 10mVP-P

• Wide Input Voltage Range: 4.2V to 42V Operating

• Adjustable Switching Frequency: 200kHz to 2.2MHz

• Integrated Boost and Catch Diodes

• 750mA Output Current

• Excellent Start-Up and Dropout Performance

• Fixed Output Voltages: 3.3V, 5V1.9μA IQat 12VIN

• 1.9μA IQat 12VIN

• Accurate Programmable Undervoltage Lockout

• Low Shutdown Current: IQ= 0.75μA

• Internal Catch Diode Current Limit

• Power Good Flag

• Thermal Shutdown

• Small, Thermally Enhanced 10-Lead MSOP and (3mm × 3mm) DFN Packages

Description

The LT3973 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. Current mode topology is used for fast transient response and good loop stability. A catch diode current limit provides protection against shorted outputs and overvoltage conditions, with thermal shutdown providing additional fault protection. An accurate programmable undervoltage lockout feature is available, producing a low shutdown current of 0.75μA. A power good flag signals when VOUTreaches 90% of the programmed output voltage. The LT3973 is available in small, thermally enhanced 10-lead MSOP and 3mm × 3mm DFN packages.ApplicationsAutomotive Battery RegulationPower for Portable ProductsIndustrial SuppliesGate Drive Bias