LMR66420

The LMR664x0 is a small 36-V, 3-A (available in 2-A and 1-A variants) synchronous step-down DC/DC converter in an enhanced HotRod QFN package. This easy-to-use converter supports a wide input voltage range of 2.7 V to 36 V (after start-up or after operating) with transients up to 42 V.

The LMR664x0 is specifically designed to meet low standby power requirements for always-on, industrial applications. Auto mode enables frequency foldback when operating at light loads, allowing an unloaded typical current consumption of 1.5 µA at 13.5 VIN and high light load efficiency. A seamless transition between PWM and PFM modes along with very low MOSFET ON resistances makes sure there is exceptional efficiency across the entire load range. The control architecture (peak current mode) and feature set are optimized for an ultra-small design size with minimal output capacitance. The device minimizes input filter size by using dual-random spread spectrum (DRSS), a low-EMI enhanced HotRod QFN package, and an optimized pin-out. The MODE/SYNC and RT pin variants can be used to set or synchronize the frequency to avoid noise sensitive frequency bands. There are NC pins between critical high voltage pins, reducing potential failures (optimal pin FMEA). The rich feature set of the LMR664x0 is designed to simplify implementation for a wide range of industrial end equipment.