LM5149RGYR

The LM5149 is a 80-V, ultra-low IO 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 LM5149 can be set up in interleaved dual-phase mode with accurate current sharing for high-current applications. The device can operate with VIN as low as 3.5 V, at nearly 100% duty cycle if needed. The LM5149 has two unique EMI reduction features: active EMI filter and dual random spread spectrum (DRSS). The 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 disturbance. DRSS combines low-frequency triangular and high-frequency randomized modulations to mitigate EMI 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 LM5149 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 and bootstrap diode, internal 3-ms soft-start time, and thermal shutdown protection with automatic recovery. The LM5149- controller comes in a 3.5-mm × 5.5-mm thermally enhanced, 24-pin VQFN package with an exposed pad to aid in thermal dissapation.

Applications

• Building automation
• Industrial transport
• Wireless infrastucture
• Test and measurement

Key features

• Functional Safety-Capable Documentation available to aid functional safety system design
• Active EMI Filter for enhanced EMI performance at lower frequencies
• Selectable 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 input filter size by 50% and lowers systems cost
• Optimized for CISPR 32 Class B requirements
• Versatile synchronous buck DC/DC controller
• Wide input voltage range of 3.5 V to 80 V
• 1% accurate, fixed 3.3 V, 5 V, 12 V, or adjustable output from 0.8 V to 55 V
• 150°C maximum junction temperature
• Shutdown mode current: 2.3 μA
• No-load sleep current: 9.5 μA
• Stackable up to two phases
• Advanced dropout with frequency foldbac
• 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 LM5149 with WEBENCH Power Designer