Description:

The LM5143A-Q1 is a 65V synchronous step-down DC/DC controller designed for high-current single or dual outputs. This device, derived from the wide VIN range controller family, employs an interleaved stackable peak current-mode control architecture that enables simple loop compensation, fast transient response, excellent load and line regulation, and accurate current sharing through paralleled phases for high output currents. An ultra-short 65 ns minimum on-time for the high-side switch facilitates large step-down ratios, supporting direct step-down conversion from 12V, 24V, or 48V inputs to low-voltage rails, thereby reducing system complexity and cost. The LM5143A-Q1 continues to operate with nearly 100% duty cycle as needed during input voltage droops down to 3.5V. A 15 µA no-load quiescent current, along with regulated output voltage, extends the operating runtime of battery-powered automotive systems. Powering the LM5143A-Q1 from the output of the switching regulator or other available supplies enables lower input quiescent current and power dissipation.

Features:

• AEC-Q100 qualified for automotive applications:

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

• Functional safety capable

– Documentation available to aid in functional safety system design

• Versatile synchronous step-down DC/DC controller

– Wide input voltage range: 3.5V to 65V

– 1% accuracy, 3.3V/5V fixed output or 0.6V to 55V adjustable output voltage

– 150°C maximum junction temperature

– 3.3 µA typical shutdown-mode current

– 15 µA typical no-load standby current

• Two interleaved synchronous step-down channels

– Dual-channel or single-output multiphase operation

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

– 60 ns tOFF(min) for low dropout operation

• 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 to reduce peak emissions

• 100 kHz to 2.2 MHz switching frequency

– Synchronization input and synchronization output capability

– Selectable diode emulation or FPWM mode

• VQFN-40 package with wettable flanks

• Create custom designs using LM5143A-Q1 with WEBENCH® Power Designer

Applications:

• Automotive electronic systems

• Infotainment systems, instrument clusters

• Advanced Driver Assistance Systems (ADAS)

• Body electronics and lighting