LT8640LT8640-1 Series

42V, 5A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current

Catalog

42V, 5A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current

Part	Number of Outputs	Topology	Supplier Device Package	Current - Output	Voltage - Input (Max) [Max]	Function	Output Type	Voltage - Input (Min) [Min]	Voltage - Output (Max) [Max]	Frequency - Switching [Max]	Frequency - Switching [Min]	Voltage - Output (Min/Fixed) [Min]	Mounting Type	Output Configuration	Operating Temperature [Max]	Operating Temperature [Min]	Package / Case	Voltage - Output (Min/Fixed)	Output Type
Analog Devices LT8640HUDC-1#TRPBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down	Adjustable	3.4 V	42 V	2 MHz	210 kHz	0.97 V	Surface Mount	Positive	150 °C	-40 °C	18 Leads 20-WFQFN Exposed Pad
Analog Devices LT8640JUDCF#PBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down	Adjustable	3.4 V	42 V	2 MHz	210 kHz	0.97 V	Surface Mount Wettable Flank	Positive	125 ¯C	-40 °C	18 Leads 20-WFQFN Exposed Pad
Analog Devices LT8640EUDCF-1#PBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down	Adjustable	3.4 V	42 V	2 MHz	210 kHz	0.97 V	Surface Mount Wettable Flank	Positive	125 ¯C	-40 °C	18 Leads 20-WFQFN Exposed Pad
Analog Devices LT8640EUDC#PBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down	Adjustable	3.4 V	42 V	2 MHz	210 kHz	0.97 V	Surface Mount	Positive	125 ¯C	-40 °C	18 Leads 20-WFQFN Exposed Pad
Analog Devices LT8640HUDCF#TRPBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down	Adjustable	3.4 V	42 V	2 MHz	210 kHz	0.97 V	Surface Mount Wettable Flank	Positive	150 °C	-40 °C	18 Leads 20-WFQFN Exposed Pad
Analog Devices LT8640HUDC#TRPBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down	Adjustable	3.4 V	42 V	2 MHz	210 kHz	0.97 V	Surface Mount	Positive	150 °C	-40 °C	18 Leads 20-WFQFN Exposed Pad
Analog Devices LT8640SIV#TRPBF	1	Buck	24-LQFN (4x4)	6 A	42 V	Step-Down	Adjustable	3 V	42 V	3 MHz	200 kHz	0.97 V	Surface Mount	Positive	125 ¯C	-40 °C	24-TFQFN Exposed Pad
Analog Devices LT8640EUDC#TRPBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down	Adjustable	3.4 V	42 V	2 MHz	210 kHz	0.97 V	Surface Mount	Positive	125 ¯C	-40 °C	18 Leads 20-WFQFN Exposed Pad
Analog Devices LT8640AJUDCM-3.3#TRPBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down		2.9 V		3 MHz	200 kHz		Surface Mount Wettable Flank	Positive	150 °C	-40 °C	20-WFQFN Exposed Pad 18 Leads	3.3 V	1.81 mOhm
Analog Devices LT8640EUDCF-1#TRPBF	1	Buck	20-QFN (3x4)	5 A	42 V	Step-Down	Adjustable	3.4 V	42 V	2 MHz	210 kHz	0.97 V	Surface Mount Wettable Flank	Positive	125 ¯C	-40 °C	18 Leads 20-WFQFN Exposed Pad

Catalog

42V, 5A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current

Key Features

• Silent Switcher®ArchitectureUltralow EMI EmissionsSpread Spectrum Frequency Modulation

• Ultralow EMI Emissions

• Spread Spectrum Frequency Modulation

• High Efficiency at High FrequencyUp to 96% Efficiency at 1MHz, 12VINto 5VOUTUp to 95% Efficiency at 2MHz, 12VINto 5VOUT

• Up to 96% Efficiency at 1MHz, 12VINto 5VOUT

• Up to 95% Efficiency at 2MHz, 12VINto 5VOUT

• Wide Input Voltage Range: 3.4V to 42V

• 5A Maximum Continuous Output, 7A Peak Transient Output

• Ultralow Quiescent Current Burst Mode®Operation2.5µA IQRegulating 12VINto 3.3VOUTOutput Ripple < 10mVP-P

• 2.5µA IQRegulating 12VINto 3.3VOUT

• Output Ripple < 10mVP-P

• Fast Minimum Switch On-Time: 30ns

• Low Dropout Under All Conditions: 100mV at 1A

• Forced Continuous Mode (LT8640-1 Only)

• Safely Tolerates Inductor Saturation in Overload

• Adjustable and Synchronizable: 200kHz to 3MHz

• Peak Current Mode Operation

• Output Soft-Start and Tracking

• Small 18-Lead 3mm × 4mm QFN and Side Wettable QFN

• AEC-Q100 Qualified for Automotive Applications

Description

The LT8640/LT8640-1 step-down regulator features Silent Switcher architecture designed to minimize EMI emissions while delivering high efficiency at frequencies up to 3MHz. An ultralow 2.5µA quiescent current—with the output in full regulation—enables applications requiring highest efficiency at very small load currents.The LT8640/LT8640-1 allows high VINto low VOUTconversion at high frequency with a fast minimum top switch on-time of 30ns. The SYNC/MODE pin selects between Burst Mode operation, spread spectrum mode, synchronization to an external clock, and either pulse-skipping (LT8640) or forced continuous mode (LT8640-1).PackageSYNC/MODE ≠ 0VCCOMPH-GRADECLKOUTINTERNAL CAPSLT8640QFNPulse-SkippingInternalYesNoNoLT8640-1QFNFCMInternalYesNoNoLT8640SLQFNFCMInternalNoYesYesLT8643SLQFNFCMExternalNoYesYesLT8640S-2LQFNFCMInternalYesYesNoLT8643S-2LQFNFCMExternalYesYesNoApplicationsAutomotive and Industrial SuppliesGeneral Purpose Step-DownGSM Power Supplies