LMR54410, LMR54406
SLUSEG8 – OCTOBER 2021
LMR544xx SIMPLE SWITCHER® 4-V to 36-V, 0.6-A/1-A Buck Converter
in a SOT-23 Package
1 Features
3 Description
•
Functional Safety-Capable
The LMR544xx is
a
wide-VIN, easy-to-use
synchronous buck converter capable of driving up to
1-A and 0.6-A load current. With a wide input range of
4 V to 36 V, the device is suitable for a wide range of
industrial applications for power conditioning from an
unregulated source.
– Documentation available to aid functional safety
system design
•
Configured for rugged industrial applications
– 4-V to 36-V input voltage range
– 0.6-A/1-A continuous output current
– 60-ns minimum switching on time
– 1.1-MHz fixed switching frequency
– –40°C to 150°C junction temperature range
– 98% maximum duty cycle
– Monotonic start-up with pre-biased output
– Short circuit protection with hiccup mode
– Precision enable
– ±1% tolerance voltage reference
Small solution size and ease of use
– Integrated synchronous rectification
– Internal compensation for ease of use
– SOT-23 package
The LMR544xx operates at 1.1-MHz switching
frequency to support use of relatively small inductors
for an optimized solution size. It has a PFM version
to realize high efficiency at light load and a FPWM
version to achieve constant frequency and small
output voltage ripple over the full load range. Soft-
start and compensation circuits are implemented
internally, which allow the device to be used with
minimal external components.
•
The device has built-in protection features, such as
cycle-by-cycle current limit, hiccup mode short-circuit
protection, and thermal shutdown in case of excessive
power dissipation.
•
•
Pin-to-pin compatible with the LMR14010A,
LMR50410, and TPS560430
Various options in pin-to-pin compatible package
Device Information
PACKAGE(1)
BODY SIZE (NOM)
– PFM and forced PWM (FPWM) options
PART NUMBER
LMR54410
2 Applications
SOT-23
2.90 mm × 1.60 mm
LMR54406
•
•
•
•
Major appliances
PLC, DCS, and PAC
Smart meters
General purpose wide VIN power supplies
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
VIN up to 36 V
CB
VIN
CIN
CBOOT
L
VOUT
SW
FB
EN
RFBT
GND
COUT
RFBB
Simplified Schematic
Efficiency Versus Output Current; VOUT = 5 V, 1100
kHz
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. ADVANCE INFORMATION for preproduction products; subject to change
without notice.