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.