The TPS40170-Q1 device is a full-featured, synchronous PWM buck controller that operates at an input voltage between 4.5 V and 60 V and is optimized for high-power-density, high-reliability dc-dc converter applications. The controller implements voltage-mode control with input-voltage feed-forward compensation that enables instant response to an input voltage change. The switching frequency is programmable from 100 kHz to 600 kHz. The TPS40170-Q1 device has a complete set of system protection and monitoring features such as programmable UVLO, programmable overcurrent protection (OCP) by sensing the low-side FET, selectable short-circuit protection (SCP) by sensing the high-side FET, and thermal shutdown. The ENABLE pin allows for system shutdown in a low-current (1-µA typical) mode. The controller supports pre-biased output, provides an open-drain PGOOD signal, and has closed-loop soft-start, output-voltage tracking, and adaptive dead-time control. The TPS40170-Q1 device provides accurate output-voltage regulation within 1% accuracy. Additionally, the controller implements a novel scheme of bidirectional synchronization with one controller acting as the primary and other downstream controllers acting as secondaries, synchronized to the primary in-phase or 180° out-of-phase. Secondary controllers can be synchronized to an external clock within ±30% of the free-running switching frequency. New products (LM5145-Q1 and LM5146-Q1) offer reduced BOM cost, higher efficiency, and reduced design size among many other features.