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LMR36503

ACTIVE

3-V to 65-V, 0.3-A ultra-small synchronous buck converter with 6 μA IQ

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Data sheet

LMR36503

ACTIVE
Data sheet Order now

Product details

Rating Catalog Operating temperature range (°C) -40 to 150 Topology Buck Type Converter Iout (max) (A) 0.3 Vin (min) (V) 3 Vin (max) (V) 65 Switching frequency (min) (kHz) 200 Switching frequency (max) (kHz) 2200 Features Enable, Fixed Output, Forced PWM, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Soft Start Fixed, Synchronous Rectification, Wettable flanks package EMI features Low parasitic Hotrod packaging Control mode current mode Vout (min) (V) 1 Vout (max) (V) 60 Iq (typ) (µA) 7 Duty cycle (max) (%) 98
Rating Catalog Operating temperature range (°C) -40 to 150 Topology Buck Type Converter Iout (max) (A) 0.3 Vin (min) (V) 3 Vin (max) (V) 65 Switching frequency (min) (kHz) 200 Switching frequency (max) (kHz) 2200 Features Enable, Fixed Output, Forced PWM, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Soft Start Fixed, Synchronous Rectification, Wettable flanks package EMI features Low parasitic Hotrod packaging Control mode current mode Vout (min) (V) 1 Vout (max) (V) 60 Iq (typ) (µA) 7 Duty cycle (max) (%) 98
VQFN-HR (RPE) 9 4 mm² 2 x 2
  • 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
  • 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
    • Ultra-small, 2-mm × 2-mm HotRod™ package with wettable flanks available
  • 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)
  • 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
  • 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
    • Ultra-small, 2-mm × 2-mm HotRod™ package with wettable flanks available
  • 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)

The LMR36503 is the industry smallest 65 V, 0.3 A synchronous step-down DC/DC converter in 2-mm × 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.

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.

The LMR36503 is the industry smallest 65 V, 0.3 A synchronous step-down DC/DC converter in 2-mm × 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.

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.
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Technical documentation

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* Data sheet LMR36503 3-V to 65-V, 0.3-A Ultra-Small Synchronous Buck Converter with Ultra-Low IQ datasheet (Rev. B) PDF | HTML 08 Nov 2022
Certificate LMR36503MSCEEVM EU Declaration of Conformity (DoC) 17 Apr 2024
Application note Step-Dwn (Buck) Convrtr Pwer Solutions for Programmable Logic Controller Systems (Rev. A) PDF | HTML 26 Jul 2021
Technical article Choosing buck converters and LDOs for miniature industrial automation equipment PDF | HTML 29 Jan 2020
EVM User's guide LMR36503RFEVM User's Guide 03 Apr 2019
Application brief Powering Drones With a Wide VIN DC-DC Converter (Rev. A) 05 Feb 2019
Analog Design Journal Accurately measuring efficiency of ultralow-IQ devices 22 Jan 2014

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

BOOSTXL-IOLINKM-8 — Eight port IO-Link master BoosterPack™

This BoosterPack™ was designed to operate with the LP-AM243 TI LaunchPad™ kit with Sitara™ AM243x MCU. Together this design implements an eight port IO-Link Master with fast and deterministic timing and independent cycle and bit rate configuration. This design can be used to build (...)

User guide: PDF
Not available on TI.com
Evaluation board

LMR36503EVM — 3-V to 65-V, 0.3-A ultra-small synchronous buck converter evaluation module

The LMR36503 evaluation module (EVM) is a fully assembled and tested circuit for evaluating the LMR36503 synchronous step-down converter.
User guide: PDF
Not available on TI.com
Simulation model

LMR36503R5 PSpice Unencrypted Transient Model

SNVMC52.ZIP (233 KB) - PSpice Model
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Simulation model

LMR36503RF Unencrypted PSpice Transient Model

SNVMC45.ZIP (226 KB) - PSpice Model
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Simulation model

LMR36506R PSpice Unencrypted Transient Model

SNVMBW4.ZIP (166 KB) - PSpice Model
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Calculation tool

LMR36503E-Q1-CALC — LMR36503, LMR36503-Q1, LMR36503E-Q1 converter quickstart tool

Welcome to the quickstart design tool for the LMR36503, LMR36503-Q1, and LMR36503E-Q1. This tool facilitates and assists the power supply engineer with the design of a DC/DC buck regulator based on the above converter family to meet application requirements.
Supported products & hardware

Supported products & hardware

Products
AC/DC & DC/DC converters (integrated FET)
LMR36503E-Q1 — Automotive 3V-to-65V 0.3A buck converter LMR36503 — 3-V to 65-V, 0.3-A ultra-small synchronous buck converter with 6 μA IQ LMR36503-Q1 — Automotive 3-V to 65-V, 0.3-A buck converter optimized for size and light load efficiency
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VQFN-HR (RPE) 9 Ultra Librarian
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