Linear Technology Corp. announces the LT8609, a 2A, 42V input synchronous step-down switching regulator. A unique synchronous rectification topology delivers 93 percent efficiency while switching at 2 MHz enabling designers to avoid critical noise-sensitive frequency bands, such as AM radio, while providing a highly compact solution footprint. Burst Mode® operation keeps quiescent current under 2.5µA in no-load standby conditions, making it ideal for always-on systems. The LT8609’s 3 to 42 V input voltage range makes it ideal for automotive applications which must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3 V and load dump transients in excess of 40 V. Its internal 3.5A switches can deliver up to 2A of continuous output current with peak load currents of 3A.

The LT8609 maintains a minimum dropout voltage of only 200 mV (at1A) under all conditions, enabling it to excel in scenarios such as automotive cold-crank. Spread spectrum frequency modulation and special design techniques offer low-EMI operation to minimize noise concerns in automotive and industrial environments. Furthermore, a fast minimum on-time of only 45 ns enables 2 MHz constant frequency switching from a 16 V input to a 1.5 V output. The LT8609’s 10-lead thermally enhanced MSOP package and high switching frequency keeps external inductors and capacitors small, providing a compact, thermally efficient footprint.

The LT8609 utilizes internal top and bottom high efficiency power switches with the necessary boost diode, oscillator, control and logic circuitry integrated into a single die. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 10mVPK-PK. Unique design techniques and a new high speed process enable high efficiency over a wide input voltage range, and the LT8609’s current-mode topology enables fast transient response and excellent loop stability. Other features include internal compensation, a power good flag, output soft start/tracking and thermal protection.

The LT8609EMSE is packaged in thermally enhanced MSOP-10 package and is priced at $2.50 each. An industrial temperature version, the LT8609IMSE, is tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and is priced at $2.75. All pricing is for 1,000 piece quantities and all versions are available from stock. For more information, visit

Summary of Features: LT8609

  • Wide Input Voltage Range: 3.0V to 42V
  • 2A of Continuous Output Current with 3A Peak Capability
  • Ultralow Quiescent Current Burst Mode® Operation: 2.5µA IQ Regulating 12VIN to 3.3VOUT, Output Ripple < 10mVP-P
  • High Efficiency Synchronous Operation at fSW = 2MHz: 93% Efficiency at 1A, 5VOUT from 12VIN
  • Fast Minimum Switch-On Time: 45ns
  • Spread Spectrum Frequency Modulation for Low EMI
  • Low Dropout Under All Conditions
  • Minimum Output Voltage of 0.8V
  • Allows Use of Small Inductors
  • Adjustable & Synchronizable: 200kHz to 2.2MHz
  • Current Mode Operation
  • Accurate 1V Enable Pin Threshold
  • Internal Compensation
  • Output Soft-Start & Tracking
  • Small Thermally Enhanced 10-Lead MSOP Package

Linear Technology Corp., a member of the S&P 500, has been designing, manufacturing and marketing a broad line of high performance analog integrated circuits for major companies worldwide for over three decades. The Company’s products provide an essential bridge between our analog world and the digital electronics in communications, networking, industrial, automotive, computer, medical, instrumentation, consumer, and military and aerospace systems. Linear Technology produces power management, data conversion, signal conditioning, RF and interface ICs, µModule® subsystems, and wireless sensor network products. For more information, visit