Analog Devices LT8642S

Description

The LT®8642S synchronous step-down regulator featuressecond generation Silent Switcher architecturedesigned to minimize EMI emissions while deliveringhigh efficiency at high switching frequencies. Thisincludes the integration of bypass capacitors to optimizeall the fast current loops inside and make it easyto achieve advertised EMI performance by eliminatinglayout sensitivity. This performance makes the LT8642Sideal for noise sensitive applications and environments.The fast, clean, low-overshoot switching edges enablehigh efficiency operation even at high switching frequencies,leading to a small overall solution size. Peak currentmode control with a 25ns minimum on-time allows highstep down ratios even at high switching frequencies.External compensation via the VC pin allows for fasttransient response at high switching frequencies. TheVC pin also enables current sharing and a CLKOUT pinenables synchronizing other regulators to the LT8642S.Burst Mode operation enables low standby current consumption,forced continuous mode can control frequencyharmonics across the entire output load range, or spreadspectrum operation can further reduce EMI emissions.Soft-start and tracking functionality is accessed via theSS pin, and an accurate input voltage UVLO thresholdcan be set using the EN/UV pin.

Features

• Silent Switcher®2 Architecture
• Ultralow EMI Emissions On Any PCB
• Eliminates PCB Layout Sensitivity
• Internal Bypass Capacitors Reduce Radiated EMI
• Optional Spread Spectrum Modulation
• High Efficiency at High Frequency
• Up to 96% Efficiency at 1MHz, 12VIN to 3.3VOUT
• Up to 95% Efficiency at 2MHz, 12VIN to 3.3VOUT
• Wide Input Voltage Range: 2.8V to 18V
• 10A Output Current
• External Compensation: Fast Transient Response and Current Sharing
• Low Quiescent Current Burst Mode® Operation
• 240μA IQ Regulating 12VIN to 1.2VOUT
• Output Ripple < 10mVP-P
• Fast Minimum Switch On-Time: 25ns
• Low Dropout Under All Conditions: 50mV at 1A
• Forced Continuous Mode
• Adjustable and Synchronizable: 200kHz to 3MHz
• Output Soft-Start and Power Good
• Small 24-Lead 4mm × 4mm LQFN Package

Typical applications

• General Purpose Step-Down
• Server Power Applications

More information

• Datasheet