The LM5149QRGYRQ1 is an 80V ultralow IQ synchronous step-down DC/DC controller for high current single output applications. The controller uses a peak current mode control architecture for simple loop compensation, fast transient response, and excellent load and line regulation. The LM5149-Q1 can be programmed to operate in dual-phase mode for precise current sharing for high current applications. The device can operate from VIN as low as 3.5V and near 100% duty cycle if required.

The LM5149QRGYRQ1 has two unique EMI reduction features: an active EMI filter and dual random spread spectrum (DRSS). Active EMI filters detect any noise or ripple voltage on the DC input bus and inject out-of-phase cancellation signals to reduce interference. DRSS combines low-frequency triangular modulation with high-frequency random modulation to reduce EMI in the low-frequency and high-frequency bands, respectively. This hybrid technology complies with various resolution bandwidth (RBW) settings specified in industry-standard EMC tests.

Additional features of the LM5149QRGYRQ1 include 150°C maximum operating junction temperature, user-selectable diode emulation for reduced current consumption at light loads, open-drain power-good flag for fault reporting and output monitoring, precision enable input, monotonic Start-up to pre-biased load, integrated VCC bias supply regulator and bootstrap diode, 3ms internal soft-start time and thermal shutdown protection with auto-recovery.

The LM5149QRGYRQ1 controller is housed in a 3.5mm × 5.5mm thermally enhanced 24-pin VQFN package with wettable side leads for easy optical inspection during manufacturing.