LT8685S Series

42V Quad, Gangable, Synchronous, Monolithic Step-Down Regulator

Catalog

42V Quad, Gangable, Synchronous, Monolithic Step-Down Regulator

Part	Voltage - Input (Min) [Min]	Frequency - Switching [Min]	Frequency - Switching [Max]	Voltage - Input (Max)	Grade	Function	Current - Output	Voltage - Output (Min/Fixed)	Topology	Package / Case	Synchronous Rectifier	Qualification	Mounting Type	Supplier Device Package	Number of Outputs	Output Configuration	Voltage - Output (Max)	Output Type	Operating Temperature [Max]	Operating Temperature [Min]
Analog Devices LT8685SRV#TRPBF	2.8 V 3 V	350 kHz	3 MHz	8 V 42 V	Automotive	Step-Down	2.5 A 4 A	0.7 V 0.8 V	Buck	36-TFQFN Exposed Pad		AEC-Q100	Surface Mount	36-LQFN (5x6)	4	Positive	8 V 42 V	Adjustable	150 °C	-40 °C
Analog Devices LT8685SRV#PBF	2.8 V 3 V	350 kHz	3 MHz	8 V 42 V	Automotive	Step-Down	2.5 A 4 A	0.7 V 0.8 V	Buck	36-TFQFN Exposed Pad		AEC-Q100	Surface Mount	36-LQFN (5x6)	4	Positive	8 V 42 V	Adjustable	150 °C	-40 °C

Catalog

42V Quad, Gangable, Synchronous, Monolithic Step-Down Regulator

Key Features

• Silent Switcher®2 ArchitectureUltralow EMI EmissionsOptional Spread Spectrum Modulation

• Ultralow EMI Emissions

• Optional Spread Spectrum Modulation

• Two High Voltage Synchronous Buck Regulators3V to 42V Input Voltage RangeOutput Currents Up to 2.5A per ChannelChannels May Be Connected in Parallel Using a Single Inductor

• 3V to 42V Input Voltage Range

• Output Currents Up to 2.5A per Channel

• Channels May Be Connected in Parallel Using a Single Inductor

• Two Low Voltage Synchronous Buck Regulators3V to 8V Input Voltage RangeOutput Currents Up to 4A per ChannelChannels May Be Connected in Parallel Using a Single Inductor

• 3V to 8V Input Voltage Range

• Output Currents Up to 4A per Channel

• Channels May Be Connected in Parallel Using a Single Inductor

• 12μA IQ All Channels Active and No-Load

• Flexible Supply Sequencing and Control

• Adjustable and Synchronizable: 350kHz to 3MHz

• Available in 36-Lead LQFN (5mm × 6mm)

Description

The LT8685S is a highly flexible, four channel, current mode, monolithic regulator able to power a wide range of automotive and industrial applications while occupying minimal board space.The LT8685S combines two 42V capable 2.5A buck regulators with two 8V capable 4A buck regulators. The two 42V regulators may be combined to provide up to 5A of output current using a single inductor. Similarly, the two 8V regulators may be combined to provide up to 8A of output current using a single inductor. Individual channel enable, track/soft-start and power good pins provide flexible power supply sequencing and control. The LT8685S features a Silent Switcher 2 architecture, plus selectable spread spectrum mode, to provide ultralow EMI/EMC emissions while delivering high efficiency at high switching frequencies.The LT8685S incorporates thermal shutdown and individual channel cycle-by-cycle current limit for short circuit protection and robust operation.APPLICATIONSAutomotive SystemsIndustrial Controls and Power Supplies