3.5-V to 80-V, current mode synchronous buck controller

The LM5148 is a 80-V, 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 LM5148 can be set up in idual-phase mode (paralleled output) with accurate current sharing for high-current applications. It can operate at input voltages as low as 3.5 V, at nearly 100% duty cycle if needed.

The LM5148 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 LM5148 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 3-ms soft-start time, and thermal shutdown protection with automatic recovery.

The LM5148 controller comes in a 3.5-mm × 5.5-mm thermally enhanced, 24-pin VQFN package.