LMR36503
LMR36503
www.ti.com
SNVSBB4A – DECEMBER 2019 – REVISED DECEMBER 2020
SNVSBB4A – DECEMBER 2019 – REVISED DECEMBER 2020
LMR36503 3-V to 65-V, 0.3-A Ultra-Small Synchronous Buck Converter
with Ultra-Low IQ
1 Features
3 Description
•
Designed for rugged industrial applications:
– Junction temperature range –40°C to +150°C
– Input transient protection up to 70 V
– Wide input voltage range: 3.0 V (falling
threshold) to 65 V
– Low EMI and minimized switch node ringing
– Adjustable, 5-V fixed output voltage options
available
The LMR36503 is the industry's smallest 65 V, 0.3 A
synchronous step-down DC/DC converter in 2-mm x
2-mm HotRod™ package. This easy-to-use converter
can handle input voltage transients up to 70 V,
provide excellent EMI performance and support fixed
5 V and other adjustable output voltages. The
transient tolerance reduces the necessary design
effort to protect against input overvoltage and meets
the surge immunity requirements of IEC 61000-4-5.
•
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Suited for scalable industrial power supplies:
– Pin compatible with LMR36506 (65 V, 600 mA)
– Adjustable switching frequency: 200 kHz to 2.2
MHz with RT pin variant
Minimized solution size and cost:
– Highest power density with internal
compensation and reduced external component
count
The LMR36503 uses the peak current mode control
architecture with internal compensation to maintain
stable operation with minimal output capacitance. The
LMR36503 with the right resistor selection from the
RT pin to ground can be externally programmed to
any desired switching frequency of operation over a
wide range from 200 kHz to 2.2 MHz. The precision
EN/UVLO feature allows precise control of the device
during the start-up and shutdown. The power-good
flag, with built-in glitch filter and delayed release,
offers a true indication of the system status,
eliminating the requirement for an external supervisor.
The compact solution size and rich feature set of
LMR36503 simplifies implementation for a wide range
of industrial applications.
– Ultra-small, 2-mm × 2-mm HotRod™ package
with wettable flanks
High efficiency across load range with low power
dissipation:
– >90% peak efficiency at 1 MHz (5 VOUT
adjustable)
Ultra-low operating quiescent current at no load
– 4 µA at 24 VIN to 3.3 VOUT (fixed output option)
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Device Information
PART NUMBER
PACKAGE(1)
BODY SIZE (NOM)
2 Applications
LMR36503
VQFN-HR (9)
2.00 mm × 2.00 mm
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Factory automation: field transmitters and process
sensors
Building automation: HVAC and fire safety
Appliances: garden and power tools
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
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100
90
80
70
60
50
BOOT
VIN
CIN
VIN
CBOOT
LIND
EN/
VOUT
COUT
SW
UVLO
RT
40
VCC
PGOOD
FB
VIN = 12V
VIN = 24V
VIN = 36V
VIN = 48V
VIN = 54V
30
RFBT
CVCC
20
RFBB
10
GND
0
10m
100m
1m 10m
Load Current (A)
100m
LMR3
Efficiency versus Output Current VOUT = 5 V (Fix),
1 MHz
Simplified Schematic
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. PRODUCTION DATA.
Product Folder Links: LMR36503
Copyright © 2020 Texas Instruments Incorporated
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