Analog Devices LT8685S | Demoboard EVAL-LT8685S

Description

Demonstration circuit EVAL-LT8685S-AZ is a 4-rail power supply featuring the LT ® 8685S, a 42V quad monolithic synchronous step-down silent switcher. The demo circuit is designed for 5V, 3.3V, 1.8V, and 1.2V outputs from a nominal 12V input. The 5V and 3.3V rails are powered from the 12V input, while the 1.8V and 1.2V rails are powered from one of the high voltage buck regulators of 5V or 3.3V. The current capability is 2.5A for the channels 1 and 2. The current ratings for the low voltage channels are 4A. 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 track/soft-start, current limit, independent enable and power good for each channel simplify the complex design of quad-output power converters. All regulators can be synchronized to a common external clock input or internal oscillator that can be programmed with a single resistor for switching frequency from 350kHz to 3MHz, allowing for optimal system design per specific applications.

Features

• Silent Switcher®2 Architecture
• Ultralow EMI Emissions
• Optional Spread Spectrum Modulation
• Two High Voltage Synchronous Buck Regulators
• 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 Regulators
• 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)AEC-Q100 Qualified for Automotive Applications

Typical applications

• Power Supplies
• Automotive Systems
• dustrial Controls

More information

• Datasheet
• IC product information