LT8608S Series

42V, 1.5A Synchronous Step-Down Regulator with 3μA Quiescent Current

Catalog

42V, 1.5A Synchronous Step-Down Regulator with 3μA Quiescent Current

Part	Number of Outputs	Voltage - Output (Max) [Max]	Mounting Type	Package / Case	Frequency - Switching [Max]	Frequency - Switching [Min]	Function	Voltage - Input (Min) [Min]	Operating Temperature [Min]	Operating Temperature [Max]	Current - Output	Output Configuration	Synchronous Rectifier	Voltage - Input (Max) [Max]	Voltage - Output (Min/Fixed)	Output Type	Supplier Device Package	Topology
Analog Devices LT8608SIV#TRMPBF	1	42 V	Surface Mount	12-VFQFN Exposed Pad	2.2 MHz	200 kHz	Step-Down	2.5 V	-40 °C	125 ¯C	1.5 A	Positive		42 V	0.77 V	Adjustable	12-LQFN (2x3)	Buck
Analog Devices LT8608SEV#TRMPBF	1	42 V	Surface Mount	12-VFQFN Exposed Pad	2.2 MHz	200 kHz	Step-Down	2.5 V	-40 °C	125 ¯C	1.5 A	Positive		42 V	0.77 V	Adjustable	12-LQFN (2x3)	Buck

Catalog

42V, 1.5A Synchronous Step-Down Regulator with 3μA Quiescent Current

Key Features

• Silent Switcher®2 ArchitectureUltralow EMI/EMC Emissions on Any PCBEliminates PCB Layout SensitivityInternal Bypass Capacitors Reduce Radiated EMIOptional Spread Spectrum Modulation

• Ultralow EMI/EMC Emissions on Any PCB

• Eliminates PCB Layout Sensitivity

• Internal Bypass Capacitors Reduce Radiated EMI

• Optional Spread Spectrum Modulation

• Wide Input Voltage Range: 3.0V to 42V

• Ultralow Quiescent Current Burst Mode®Operation:<3μA IQRegulating 12VINto 3.3VOUTOutput Ripple <10mVP-P

• <3μA IQRegulating 12VINto 3.3VOUT

• Output Ripple <10mVP-P

• High Efficiency 2MHz Synchronous Operation:>90% Efficiency at 0.75A, 5VOUTfrom 12VIN

• >90% Efficiency at 0.75A, 5VOUTfrom 12VIN

• 1.5A Continuous Output Current

• Fast Minimum Switch-On Time: 35ns

• Adjustable and Synchronizable: 200kHz to 2.2MHz

• Allows Use of Small Inductors

• Low Dropout

• Peak Current Mode Operation

• Internal Compensation

• Output Soft-Start and Tracking

• Small 12-Lead LQFN Package

Description

The LT8608S is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 1.7μA of quiescent current. The LT8608S can deliver 1.5A of continuous current. Top and bottom power switches are included with all necessary circuitry to minimize the need for external components. Low ripple Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mV. A SYNC pin allows synchronization to an external clock, or spread spectrum modulation of switching frequencies for low EMI operation. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VINundervoltage lockout or to shut down the LT8608S reducing the input supply current to 1μA. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up while the PG flag signals when VOUTis within ±8.0% of the programmed output voltage as well as fault conditions. The LT8608S is available in a small 12-lead LQFN package.APPLICATIONSGeneral Purpose Step DownLow EMI Step Down