1 Features

? Functional Safety-Capable

– Documentation available to aid functional safety

system design

? Integrated EMI mitigation

– Selectable dual random spread spectrum

(DRSS) feature for enhanced EMI performance

across low and high-frequency bands

– Optimized for CISPR 32 Class B requirements

? Versatile synchronous buck DC/DC controller

– Wide input voltage range of 3.5 V to 80 V

– 1 accurate, fixed 3.3 V, 5 V, 12 V, or

adjustable output from 0.8 V to 55 V

– 150°C maximum junction temperature

– Lossless DCR or shunt current sensing

– Shutdown mode current of 2.3 μA

– No-load sleep current of 9.5 μA

– Internal soft-start ramp of 3 ms

– Stackable up to two phases

– Internal bootstrap diode

? Switching frequency from 100 kHz to 2.2 MHz

– SYNC in and SYNC out capability

– Selectable PFM or FPWM modes

? Inherent protection features for robust design

– Internal hiccup mode overcurrent protection

– ENABLE and PGOOD functions

– VCC, VDDA, and gate-drive UVLO protection

– Internal or external loop compensation

– Thermal shutdown protection with hysteresis

? Create a custom design using the LM5148 with

WEBENCH? Power Designer

2 Applications

? Building automation

? Industrial transport

? Power delivery

? Test and measurement

? Aerospace and defense

3 Description

The LM5148 is a 80-V, ultra-low IQ synchronous

buck DC/DC controller for high-current, single-output

applications. The controller uses a peak current-mode

control architecture for easy loop compensation,

fast transient response, and excellent load and line

regulation. The LM5148 can be set up in idual-phase

mode (paralleled output) with accurate current sharing

for high-current applications. It can operate at input

voltages as low as 3.5 V, at nearly 100 duty cycle if

needed.

The LM5148 has a unique EMI reduction

feature known as dual random spread spectrum

(DRSS). Combining low-frequency triangular and

high-frequency random modulations mitigates EMI

disturbances across lower and higher frequency

bands, respectively. This hybrid technique aligns with

the multiple resolution bandwidth (RBW) settings

specified in industry-standard EMC tests.