 Analog Devices' LT8640 and LT8643 synchronous step-down regulators feature second-generation Silent Switcher architecture, designed to minimize EMI/EMC emissions while delivering high efficiency at high switching frequencies. This includes the integration of bypass capacitors to optimize all the fast current loops inside and make it easier to achieve advertised EMI performance by reducing layout sensitivity. This performance makes the LT8640 and LT8643 ideal for noise-sensitive applications and environments.
Analog Devices' LT8640 and LT8643 synchronous step-down regulators feature second-generation Silent Switcher architecture, designed to minimize EMI/EMC emissions while delivering high efficiency at high switching frequencies. This includes the integration of bypass capacitors to optimize all the fast current loops inside and make it easier to achieve advertised EMI performance by reducing layout sensitivity. This performance makes the LT8640 and LT8643 ideal for noise-sensitive applications and environments.
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 30 ns minimum on-time allows high step-down ratios, even at high switching frequencies.
Burst Mode operation enables ultralow standby current consumption, forced continuous mode can control frequency harmonics across the entire output load range, or spread spectrum operation can further reduce EMI/EMC emissions. Soft-start and tracking functionality is accessed via the TR/SS pin, and an accurate input voltage UVLO threshold can be set using the EN/UV pin. A CLKOUT pin enables the synchronized of other regulators to the LT8640 and LT8643.
    
        
            | Features |  |  | 
        
        
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                Silent Switcher 2 architectureUltralow EMI/EMC emissions on any PCBEliminates PCB layout sensitivityInternal bypass capacitors reduce radiated EMIOptional spread spectrum modulationHigh efficiency at high frequencyUp to 96% efficiency at 1 MHz, 12 VIN to 5 VOUTUp to 95% efficiency at 2 MHz, 12 VIN to 5 VOUTWide input voltage range: 3.4 V to 42 V6 A maximum continuous output, 7 A peak output Applications 
                Automotive and industrial suppliesGeneral purpose step-down |  | 
                Ultra-low quiescent Current Burst Mode® operation2.5 μA IQ regulating 12 VIN to 3.3 VOUTOutput ripple < 10 mVP-PFast minimum switch on-time: 30 nsLow dropout under all conditions: 100 mV at 1 AForced continuous modeSafely tolerates inductor saturation in overloadAdjustable and synchronizable: 200 kHz to 3 MHzOutput soft-start and tracking |