LM25149-Q1

• AEC-Q100 qualified for automotive applications:
  • Device temperature grade 1: –40°C to +125°C ambient operating temperature
• Two integrated EMI mitigation mechanisms
  • Active EMI filter for enhanced EMI performance at lower frequencies
  • Dual random spread spectrum (DRSS) for enhanced EMI performance across low and high-frequency bands
  • EMI reduced by an average of 25 dBµV
  • Reduces the external differential-mode filter size by 50% and lowers systems cost
• Versatile synchronous buck DC/DC controller
  • Wide input voltage range of 3.5 V to 42 V
  • 1% accurate, fixed 3.3-V, 5-V, 12-V, or adjustable outputs from 0.8 V to 36 V
  • 150°C maximum junction temperature
  • Shutdown mode current: 2.2 µA
  • No-load standby current: 9 µA
• Switching frequency from 100 kHz to 2.2 MHz
  • SYNC in and SYNC out capability
• Inherent protection features for robust design
  • Internal hiccup-mode overcurrent protection
  • ENABLE and PGOOD functions
  • VCC, VDDA, and gate-drive UVLO protection
  • Internal or external loop compensation
  • Thermal shutdown protection with hysteresis
• Create a custom design using the LM25149-Q1 with WEBENCH Power Designer

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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.