The LM5165-Q1 converter is an easy-to-use synchronous buck DC-DC regulator that operates from a 3-V to
65-V supply voltage. The device is intended for step-down conversions from 3.3-V, 5-V, 12-V, 24-V, and 48-V unregulated, semi-regulated and fully-regulated supply rails. With integrated high-side and low-side power MOSFETs, the LM5165-Q1 delivers up to 150-mA DC load current with high efficiency and ultra-low input quiescent current in a very small solution size. Designed for simple implementation, a choice of operating modes offers flexibility to optimize its usage according to the target application. In constant on-time (COT) mode of operation, ideal for low-noise, high current, fast load transient requirements, the device operates with predictive on-time switching pulse. A quasi-fixed switching frequency over the input voltage range is achieved by using an input voltage feedforward to set the on-time. Alternatively, pulse frequency modulation (PFM) mode, complemented by an adjustable peak current limit, achieves exceptional light-load efficiency performance. Control loop compensation is not required with either operating mode, reducing design time and external component count.

The LM5165-Q1 incorporates other features for comprehensive system requirements, including an open-drain Power Good circuit for power-rail sequencing and fault reporting, internally-fixed or externally-adjustable soft-start, monotonic start-up into prebiased loads, precision enable with customizable hysteresis for programmable line undervoltage lockout (UVLO), adjustable cycle-by-cycle current limit for optimal inductor sizing, and thermal shutdown with automatic recovery. These features enable a flexible and easy-to-use platform for a wide range of applications. The pin arrangement is designed for simple Layout, requiring only a few external components.