42V, 4A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current

The LT8614 step-down regulator features Silent Switcher architecture designed to minimize EMI emissions while delivering high efficiency at frequencies up to 3MHz. Assembled in a 3mm × 4mm QFN, the monolithic construction with integrated power switches and inclusion of all necessary circuitry yields a solution with a minimal PCB footprint. An ultralow 2.5μA quiescent current—with the output in full regulation— enables applications requiring highest efficiency at very small load currents. Transient response remains excellent and output voltage ripple is below 10mVP-P at any load, from zero to full current.

The LT8614 allows high VIN to low VOUT conversion at high frequency with a fast minimum top switch on-time of 30ns. Operation is safe in overload even with a saturated inductor.

Essential features are included and easy to use: An open-drain PG pin signals when the output is in regulation. The SYNC pin allows clock synchronization and choice of Burst Mode operation or pulse-skipping mode. Soft-start and tracking functionality is accessed via the TR/SS pin. An accurate enable threshold can be set using the EN/UV pin and a resistor at the RT pin programs switch frequency.

Applications

* Automotive and Industrial Supplies

* General Purpose Step-Down

* GSM Power Supplies

* Silent Switcher® Architecture

* Ultralow EMI Emissions

* High Efficiency at High Frequency

* Up to 96% Efficiency at 1MHz, 12VIN to 5VOUT

* Up to 94% Efficiency at 2MHz, 12VIN to 5VOUT

* Wide Input Voltage Range: 3.4V to 42V

* Ultralow Quiescent Current Burst Mode® Operation:

* 2.5μA IQ Regulating 12VIN to 3.3VOUT

* Output Ripple < 10mVP-P