LT8609 - 42V, 2A/3A Peak Synchronous Step-Down Regulator

Linear Technology Corporation’s LT8609 is a 2A, 42V input synchronous step-down switching regulator with unique synchronous rectification topology that delivers 93% efficiency while switching at 2MHz.

This enables designers to avoid noise-sensitive frequency bands, such as AM radio, while providing a highly compact package.

LTC’s Burst Mode® operation keeps quiescent current under 2.5μA while not under load (standby mode), making it ideal for always-on systems. The LT8609’s 3.0V to 42V 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 3.0V and load dump transients in excess of 40V.

The LT8609 maintains a minimum dropout voltage of only 200mV (at1A) under all conditions, making it ideal for automotive cold-cranking. Noise concerns in automotive and industrial environments are also addressed through spread spectrum frequency modulation and special design techniques to offer low-EMI operation.

A fast minimum on-time of only 45ns also 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 features internal top and bottom high efficiency power switches with the necessary boost diode, oscillator, control and logic circuitry integrated into a single die.

Other design benefits such as low-ripple Burst Mode operation, which maintains high efficiency at low output currents while keeping output ripple below 10mVPK-PK, and a new high speed process that enables high efficiency over a wide input voltage range, enable fast transient response and excellent loop stability. The LT8609’s feature set is rounded off by internal compensation, a power good flag, output soft start/tracking and thermal protection.