2A Synchronous Step-Down 2MHz DC-DC Delivers 93% Efficiency
Linear Technology Corporation announces the LT8609, a 2A, 42V input synchronous step-down switching regulator. A unique synchronous rectification topology delivers 93% efficiency while switching at 2MHz 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 3.0V to 42V input voltage range makes it suited for automotive applications which must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3.0V and load dump transients in excess of 40V. 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 200mV (at 1A) 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 45ns enables 2MHz constant frequency switching from a 16V input to a 1.5V 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 to 125 degrees 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.
