1 Features

• AEC-Q100 qualified for automotive applications:

– Device temperature grade 1: –40°C to +125°C

ambient operating temperature

• Functional Safety-Capable

– Documentation available to aid functional safety

system design

• Versatile synchronous buck DC/DC controller

– Wide input voltage range of 3.5 V to 65 V

– 1 accurate, fixed 3.3-V, 5-V, or adjustable

outputs from 0.6 V to 55 V

– 150°C maximum junction temperature

– 3.3-μA typical shutdown mode current

– 15-μA typical no-load standby current

• Two interleaved synchronous buck channels

– Dual channel or single-output multiphase

– 65-ns tON(min) for high VIN/VOUT ratio

– 60-ns tOFF(min) for low dropout

• Inherent protection features for robust design

– Hiccup mode overcurrent protection

– Independent ENABLE and PGOOD functions

– Adjustable output voltage soft start

– VCC, VDDA, and gate-drive UVLO protection

– Thermal shutdown protection with hysteresis

• Optimized for CISPR 25 class 5 EMI requirements

– Slew-rate controlled adaptive gate drivers

– Spread spectrum reduces peak emissions

• 100-kHz to 2.2-MHz switching frequency

– SYNC in and SYNC out capability

– Selectable diode emulation or FPWM modes

• VQFN-40 package with wettable flank pins

• Create a custom design using the LM5143A-Q1

with WEBENCH® Power Designer

2 Applications

• Automotive electronic systems

• Infotainment systems, instrument clusters

• Advanced driver assistance systems (ADAS)

• Body electronics and lighting

3 Description

The LM5143A-Q1 is a 65-V DC/DC synchronous

buck controller for high-current single or dual outputs.

Deriving from a family of wide-VIN range controllers,

the device uses an interleaved, stackable, peak

current-mode control architecture for easy loop

compensation, fast transient response, excellent load

and line regulation, and accurate current sharing with

paralleled phases for higher output current. A highside

switch minimum on time of 65 ns provides large

step-down ratios, enabling the direct conversion from

12-V, 24-V, or 48-V inputs to low-voltage rails for

reduced system complexity and cost. The LM5143AQ1

continues to operate during input voltage dips as

low as 3.5 V, at nearly 100 duty cycle if needed.

The 15-μA no-load quiescent current with the

output voltage in regulation extends operating runtime

in battery-powered automotive systems. Power

the LM5143A-Q1 from the output of the switching

regulator or another available source for even lower

input quiescent current and power loss.