Analog Devices Inc. LT8640/LT8640-1 Step-Down Regulators

Analog Devices Inc. LT8640/LT8640-1 Step-Down Regulators feature Silent Switcher architecture designed to minimize EMI/EMC emissions while delivering high efficiency at frequencies up to 3MHz. An ultralow 2.5µA quiescent current—with the output in full regulation—enables applications requiring the highest efficiency at very small load currents. The LT8640/LT8640-1 allows high VIN to low VOUT conversion at high frequency with a fast minimum top switch on-time of 30ns. The SYNC/MODE pin selects between Burst Mode operation, spread spectrum mode, synchronization to an external clock, and either pulse-skipping (LT8640) or forced continuous mode (LT8640-1).


  • Silent Switcher® architecture
    • Ultra-low EMI/EMC emissions
    • Spread spectrum frequency modulation
  • High efficiency at high frequency
    • Up to 96% efficiency at 1MHz, 12VIN to 5VOUT
    • Up to 95% efficiency at 2MHz, 12VIN to 5VOUT
  • 3.4V to 42V wide input voltage range 
  • 5A maximum continuous output, 7A peak transient output
  • Ultra-low quiescent current Burst Mode® operation
    • 2.5µA IQ regulating 12VIN to 3.3VOUT
    • Output Ripple < 10mVP-P
  • 30ns fast minimum switch on-time
  • 100mV at 1A low dropout under all conditions 
  • Forced continuous mode (LT8640-1 only)
  • Safely tolerates inductor saturation in overload
  • 200kHz to 3MHz adjustable and synchronizable
  • Peak current mode operation
  • Output soft-start and tracking
  • Small 18-lead 3mm×4mm QFN and side wettable QFN


  • Automotive supplies
  • Industrial supplies
  • General-purpose step-down
  • GSM power supplies

Typical Application

Application Circuit Diagram - Analog Devices Inc. LT8640/LT8640-1 Step-Down Regulators
Publicado: 2018-12-18 | Actualizado: 2023-02-15