1 Features
• 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 tON(min) for high VIN / VOUT ratio
– 140-ns tOFF(min) for low dropout
– Lossless RDS(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 VTH 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

2 Applications
• Wireless infrastructure, cloud computing
• Industrial motor drives, test and measurement
• Personal transport vehicle: electric bike
• Asset tracking and fleet management systems
• Non-isolated PoE, IP cameras
• Inverting buck-boost regulators

3 Description
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 highperformance
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.