LM25149-Q1

The LM25149-Q1 is a 42-V synchronous buck DC/DC controller for high-current single-output applications. Refer to the Errata. The device uses peak current-mode control architecture for easy loop compensation, fast transient response, and excellent load and line regulation. The LM25149-Q1 can be set up in interleaved mode (paralleled output) with accurate current sharing for high-current applications. The LM25149-Q1 can operate at input voltages as low as 3.5 V, at nearly 100% duty cycle if needed.

The LM25149-Q1 has two unique EMI reduction features: active EMI filter and Dual Random Spread Spectrum (DRSS). Active EMI filter senses any noise or ripple voltage on the DC input bus and injects an out-of-phase cancellation signal to reduce the noise or ripple voltage. DRSS combines a low-frequency triangular and high-frequency random modulation to optimize EMI preformance in the low-frequency and high-frequency radio frequency bands.

Additional features of the LM25149-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 2.8-ms soft-start time, and thermal shutdown protection with automatic recovery.

The LM25149-Q1 controller comes in a 3.5-mm × 5.5-mm thermally-enhanced, 24-pin VQFN package with wettable flank pins to facilitate optical inspection during manufacturing.