3.5-V to 65-V low Iq, dual, 2-phase synchronous buck DC-DC controller

The LM5143-Q1 is a 65-V synchronous buck DC/DC controller for high-current single or dual outputs. The device uses an interleaved, stackable, peak current-mode control architecture for easy loop compensation, fast transient response, excellent load and line regulation, and accurate current sharing with paralleled phases for higher output current. A high-side switch minimum on-time of 65 ns gives large step-down ratios, enabling the direct conversion from 12-V, 24-V, or 48-Vautomotive inputs to low-voltage rails for reduced system complexity and solution cost. The LM5143-Q1 continues to operate during input voltage dips as low as 3.5 V, at nearly 100% duty cycle if needed.

Current is sensed using the inductor DCR for highest efficiency or an optional shunt resistor for high accuracy. The 15-µA no-load quiescent current with the output voltage in regulation extends operating run-time in battery-powered systems. Power the LM5143-Q1 from the output of the switching regulator or another available source for even lower input quiescent current and power loss.