LM5146

• Functional Safety-Capable
  • Documentation available to aid functional safety system design
• Versatile synchronous buck DC/DC controller
  • Wide input voltage range of 5.5 V to 100 V
  • 150°C maximum junction temperature
  • 0.8-V reference with ±1% feedback accuracy
  • Adjustable output voltage from 0.8 V to 60 V
  • 40-ns t_ON(min) for high V_IN / V_OUT ratio
  • 140-ns t_OFF(min) for low dropout
  • Lossless R_DS(on) or shunt current sensing
  • Optimized for CISPR 11 and CISPR 32 Class B EMI requirements
• Switching frequency from 100 kHz to 1 MHz
  • SYNC in and SYNC out capability
  • Selectable diode emulation or FPWM
• 7.5-V gate drivers for standard V_TH MOSFETs
  • 14-ns adaptive dead-time control
  • 2.3-A source and 3.5-A sink capability
• Fast line and load transient response
  • Voltage-mode control with line feedforward
  • High gain-bandwidth error amplifier
• Inherent protection features for robust design
  • Adjustable output voltage soft start
  • Hiccup-mode overcurrent protection
  • Input UVLO with hysteresis
  • VCC and gate-drive UVLO protection
  • Precision enable input and open-drain PGOOD indicator for sequencing and control
  • Thermal shutdown protection with hysteresis
• 20-pin VQFN package with wettable flanks
• Create a custom design using the LM5146 with WEBENCH Power Designer

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The LM5146 100-V synchronous buck controller regulates from a high input voltage source or from an input rail subject to high-voltage transients, minimizing the need for external surge suppression components. A high-side switch minimum on-time of 40 ns gives large step-down ratios, enabling the direct step-down conversion from a 48-V nominal input to low-voltage rails for reduced system complexity and solution cost. The LM5146 continues to operate during input voltage dips as low as 5.5 V, at nearly 100% duty cycle if needed, making it an excellent choice for high-performance industrial controls, robotics, datacom, and RF applications.

Forced-PWM (FPWM) operation eliminates switching frequency variation to minimize EMI, while user-selectable diode emulation lowers current consumption at light-load conditions. The adjustable switching frequency as high as 1 MHz can be synchronized to an external clock source to eliminate beat frequencies in noise-sensitive applications.