Analog Devices LT8650S | Demoboard LT Journal V1.2018

Description

LTJournalThe LT®8650S is a dual step-down regulator that delivers up to 4A of continuous current from both channels and supports loads up to 6A from each channel. The LT8650S features the second generation Silent Switcher architecture to minimize EMI emissions while delivering high efficiency at high switching frequencies. This includes integration of bypass capacitors to optimize high frequency current loops and make it easy to achieve advertised EMI performance by eliminating layout sensitivity.The fast, clean, low-overshoot switching edges enable high efficiency operation even at high switching frequencies, leading to a small overall solution size. Peak current mode control with a 40ns minimum on-time allows high step down ratios at high switching frequencies.Burst Mode operation features a 6.2μA quiescent current resulting in high efficiency at low output currents, forced continuous mode allows fixed switching frequency operation over the entire output load range, and spread spectrum operation can further reduce EMI emissions. External VC pins allow optimal loop compensation for fast transient response. The VC pins can also be used for current sharing and the CLKOUT pin enables synchronizing two LT8650S chips to generate a 4-phase, 16A supply.

Features

• Silent Switcher®2 Architecture:
• Ultralow EMI on Any PCB
• Eliminates PCB Layout Sensitivity
• Internal Bypass Capacitors Reduce Radiated EMI
• Optional Spread Spectrum Modulation
• 4A DC from Each Channel Simultaneously
• Up to 6A on Either Channel
• Ultralow Quiescent Current BurstMode® Operation:
• 6.2μA IQ Regulating 12VIN to 5VOUT1 and 3.3VOUT2
• Output Ripple <10mVP-P
• Optional External VC Pin: Fast Transient Responseand Current Sharing (Extra 50μA IQ/Channel)
• Forced Continuous Mode
• High Efficiency at High Frequency
• 94.6% Efficiency at 2A, 5VOUT from 12VIN at 2MHz
• 93.3% Efficiency at 4A, 5VOUT from 12VIN at 2MHz
• Fast Minimum Switch-On Time: 40ns
• Wide Input Voltage Range: 3.0V to 42V
• Adjustable and Synchronizable: 300kHz to 3MHz
• Small 4mm × 6mm 32-Pin LQFN Package

Typical applications

• General Purpose Step-Down
• Automotive and Industrial Supplies

More information

• Datasheet
• IC product information