Analog Devices LT8643S

Description

The LT®8640S/LT8643S synchronous step-down regulatorfeatures second generation Silent Switcher architecturedesigned to minimize EMI/EMC emissions while deliveringhigh efficiency at high switching frequencies. Thisincludes the integration of bypass capacitors to optimizeall the fast current loops inside and make it easy to achieveadvertised EMI performance by reducing layout sensitivity.This performance makes the LT8640S/LT8643S ideal fornoise- sensitive applications and environments.The fast, clean, low overshoot switching edges enable highefficiency operation even at high switching frequencies,leading to a small overall solution size. Peak currentmode control with a 30ns minimum on-time allows highstep-down ratios even at high switching frequencies.The LT8643S has external compensation via the VC pinto enable current sharing and fast transient responseat high switching frequencies. A CLKOUT pin enablessynchronizing other regulators to the LT8640S/LT8643S.Burst Mode operation enables ultralow standby currentconsumption, forced continuous mode can controlfrequency harmonics across the entire output load range,or spread spectrum operation can further reduce EMI/EMC emissions. Soft-start and tracking functionality isaccessed via the TR/SS pin, and an accurate input voltageUVLO threshold can be set using the EN/UV pin.

Features

nn Silent Switcher ®2 Architecturenn Ultralow EMI/EMC Emissions on Any PCBnn Eliminates PCB Layout Sensitivitynn Internal Bypass Capacitors Reduce Radiated EMInn Optional Spread Spectrum Modulationnn High Efficiency at High Frequencynn Up to 96% Efficiency at 1MHz, 12VIN to 5VOUTnn Up to 95% Efficiency at 2MHz, 12VIN to 5VOUTnn Wide Input Voltage Range: 3.4V to 42Vnn 6A Maximum Continuous, 7A Peak Outputnn Ultralow Quiescent Current Burst Mode® Operationnn 2.5μA IQ Regulating 12VIN to 3.3VOUT (LT8640S)nn Output Ripple < 10mVP-Pnn External Compensation: Fast Transient Responseand Current Sharing (LT8643S)nn Fast Minimum Switch On-Time: 30nsnn Low Dropout Under All Conditions: 100mV at 1Ann Forced Continuous Modenn Adjustable and Synchronizable: 200kHz to 3MHznn Output Soft-Start and Trackingnn Small 24-Lead 4mm × 4mm LQFN Package

Typical applications

• automotive and industrial Supplies
• General purpose step-Down

More information

• Datasheet
• IC product information