Automotive 42-V synchronous buck DC/DC controller with ultra-low IQ

The LM25148-Q1 is a 42V, ultra-low IQ synchronous buck DC/DC controller for high-current, single-output applications. The controller uses a peak current-mode control architecture for easy loop compensation, fast transient response, and excellent load and line regulation. The LM25148-Q1 can be set up in dual-phase mode (paralleled output) with accurate current sharing for high-current applications. The device can operate at input voltages as low as 3.5V, at nearly 100% duty cycle if needed.

The LM25148-Q1 has a unique EMI reduction feature known as Dual Random Spread Spectrum (DRSS). Combining low-frequency triangular and high-frequency random modulations mitigates EMI disturbances across lower and higher frequency bands, respectively. This hybrid technique aligns with the multiple resolution bandwidth (RBW) settings specified in industry-standard EMC tests.

Additional features of the LM25148-Q1 include 150°C maximum junction temperature operation, user-selectable diode emulation for lower current consumption at light-load conditions, open-drain power-good flag for fault reporting and output monitoring, precision enable input, monotonic start-up into prebiased load, integrated VCC bias supply regulator, internal 3ms soft-start time, and thermal shutdown protection with automatic recovery.