DESCRIPTION
The LT®8685S 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.

FEATURES
n Silent Switcher®2 Architecture
n Ultralow EMI Emissions
n Optional Spread Spectrum Modulation
n Two High Voltage Synchronous Buck Regulators
n 3V to 42V Input Voltage Range
n Output Currents Up to 2.5A per Channel
n Channels May Be Connected in Parallel Using a
Single Inductor
n Two Low Voltage Synchronous Buck Regulators
n 3V to 8V Input Voltage Range
n Output Currents Up to 4A per Channel
n Channels May Be Connected in Parallel Using a
Single Inductor
n 12μA IQ All Channels Active and No-Load
n Flexible Supply Sequencing and Control
n Adjustable and Synchronizable: 350kHz to 3MHz
n Available in 36-Lead LQFN (5mm × 6mm)
n AEC-Q100 Qualified for Automotive Applications

APPLICATIONS
n Automotive Systems
n Industrial Controls and Power Supplies