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.