The LM5125A-Q1 is a stackable, dual-phase, synchronous boost controller. The device provides a regulated output voltage for lower or equal input voltage also supporting VI to VOUT bypass mode to save power. Stack two devices with or without external clock. Dynamically program VOUT using the analog or digital ATRK/DTRK function. VI is supported down to 2.5V after start-up as the internal VCC supply is automatically switched from VBIAS to VOUT for VBIAS < 4.5V. The fixed switching frequency is set between 100kHz and 2.2MHz through a resistor on the RT pin or the SYNCIN clock. The switching modes FPWM or diode emulation can be changed during operation. The implemented protections peak current limit, average input current limit, average inductor current monitor, over and undervoltage protection, and the thermal shutdown protect the device and the application.