LM3481

ACTIVE

2.97V to 48V High-Efficiency Controller for Boost, SEPIC and Flyback

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Product details

Parameters

Vin (Min) (V) 2.97 Vin (Max) (V) 48 Vout (Min) (V) 1.26 Vout (Max) (V) 500 Regulated outputs (#) 1 Switching frequency (Min) (kHz) 100 Switching frequency (Max) (kHz) 1000 Iq (Typ) (mA) 3.7 Features Adjustable Current Limit, Enable, Frequency Synchronization, Light Load Efficiency, Pre-Bias Start-Up, UVLO Adjustable Duty cycle (Max) (%) 85 Rating Catalog Operating temperature range (C) -40 to 125 open-in-new Find other Boost controllers (external switch)

Package | Pins | Size

VSSOP (DGS) 10 9 mm² 3 x 3 open-in-new Find other Boost controllers (external switch)

Features

  • LM3481QMM are Automotive-Grade Products
    That are AEC-Q100 Grade 1 Qualified (–40°C to
    +125°C Operating Junction Temperature)
  • 10-Lead VSSOP Package
  • Internal Push-Pull Driver With 1-A Peak Current
    Capability
  • Current Limit and Thermal Shutdown
  • Frequency Compensation Optimized With a Capacitor
    and a Resistor
  • Internal Softstart
  • Current Mode Operation
  • Adjustable Undervoltage Lockout With Hysteresis
  • Pulse Skipping at Light Loads
  • Key Specifications
    • Wide Supply Voltage Range of 2.97 V to 48 V
    • 100-kHz to 1-MHz Adjustable and Synchronizable
      Clock Frequency
    • ±1.5% (Over Temperature) Internal
      Reference
    • 10-µA Shutdown Current (Over Temperature)
open-in-new Find other Boost controllers (external switch)

Description

The LM3481 device is a versatile Low-Side N-FET high-performance controller for switching regulators. The device is suitable for use in topologies requiring a low-side FET, such as boost, flyback, SEPIC, and so on. The LM3481 device can be operated at extremely high switching frequencies to reduce the overall solution size. The switching frequency of the LM3481 device can be adjusted to any value between 100kHz and 1MHz by using a single external resistor or by synchronizing it to an external clock. Current mode control provides superior bandwidth and transient response in addition to cycle-by-cycle current limiting. Current limit can be programmed with a single external resistor.

The LM3481 device has built-in protection features such as thermal shutdown, short-circuit protection and overvoltage protection. Power-saving shutdown mode reduces the total supply current to 5 µA and allows power supply sequencing. Internal soft-start limits the inrush current at start-up.

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Similar but not functionally equivalent to the compared device:
LM5155 ACTIVE 2.2MHz wide VIN non-synchronous boost controller For applications requiring lower quiescent current or higher efficiency.

Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 17
Type Title Date
* Datasheet LM3481 / -Q1 High-Efficiency Controller for Boost, SEPIC and Flyback DC-DC Converters datasheet (Rev. F) Nov. 05, 2012
Application note LM34xx How to Design Flyback Converter with LM3481 Boost Controller (Rev. A) Apr. 08, 2019
Technical articles How to add overvoltage protection to a synchronous boost controller Sep. 17, 2018
Selection guide Power Management Guide 2018 (Rev. R) Jun. 25, 2018
Technical articles Eliminating noise from the factory floor Sep. 29, 2016
User guide LM3481 flyback EVM User's Guide May 19, 2016
Technical articles How do you generate a high voltage from a single cell Li Ion battery? Dec. 11, 2015
Application note Softstart Using Constant Current Constant Voltage Approach Jul. 24, 2015
Technical articles Portable speaker power: Making the bass possible May 12, 2015
Application note Demystifying Type II and Type III Compensators Using Op-Amp and OTA for DC/DC Co Jul. 11, 2014
User guide AN-1756 LM3481 Evaluation Board (Rev. A) May 01, 2013
User guide AN-2094 LM3481 SEPIC Evaluation Board (Rev. A) Apr. 25, 2013
Application note AN-1286 Compensation For The LM3478 Boost Controller (Rev. C) Apr. 23, 2013
Application note AN-1484 Designing A SEPIC Converter (Rev. E) Apr. 23, 2013
Application note AN-1990 Compensation for Current Mode Control SEPIC Converters (Rev. A) Apr. 23, 2013
Application note Modeling & Design of Current Mode Control Boost Converters (Rev. B) Apr. 23, 2013
User guide 330mW AC or DC Tiny Flyback Converter Power Supply Reference Design User Guide Jan. 27, 2012

Design & development

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

Hardware development

EVALUATION BOARD Download
49
Description
The Texas Instruments LM3481-FLYBACKEVM helps designers evaluate the performance of the LM3481 DC/DC Boost Controller in an isolated flyback topology. The EVM operates from an 5.5V to 36V input and provides a Isolated  12V output at 2A.
Features
  • Current Mode Operation
  • Adjustable Undervoltage Lockout With Hysteresis
  • Pulse Skipping at Light Loads
  • Internal Push-Pull Driver With 1-A Peak Current Capability
EVALUATION BOARD Download
99
Description

The LM3481 is a current mode, low side N channel FET controller. It can be utilized in numerous configurations including a Boost, Flyback or SEPIC (Single Ended Primary Inductor Converter). This evaluation board demonstrates the flexibility of the LM3481 in a boost topology providing 12 volt output (...)

EVALUATION BOARD Download
99
Description

The LM3481 SEPIC evaluation board is designed to provide the design engineer with a fully functional power converter solution with two output voltage options. It produces a selectable output voltage of 12 V at 1.25A or 5V at 3A. The switching frequency for the converter is set to 500 kHz. The (...)

Features

5V Output Voltage Option:

  • Input Voltage Range : 4.5V to 25V
  • Output Voltage : 5V ± 2%
  • Output Current : 0A to 3A
  • Switching Frequency : 500 kHz
  • Load Regulation : 0.1%
  • Board Size : 2.4 x 1.8 inches


12V Output Voltage Option:

  • Input Voltage Range : 4.5V to 18V
  • Output Voltage : 12V ± 2%
  • Output Current : 0A to 1.25A
  • (...)

Design tools & simulation

SIMULATION MODEL Download
SNVM170.ZIP (54 KB) - PSpice Model
SIMULATION MODEL Download
SNVM229C.TSC (600 KB) - TINA-TI Reference Design
SIMULATION MODEL Download
SNVM230C.ZIP (29 KB) - TINA-TI Spice Model
SIMULATION MODEL Download
SNVM418B.TSC (600 KB) - TINA-TI Reference Design
SIMULATION MODEL Download
SNVM713D.ZIP (117 KB) - PSpice Model
SIMULATION MODEL Download
SNVMA06.TSC (58 KB) - TINA-TI Reference Design
SIMULATION MODEL Download
SNVMA07.ZIP (8 KB) - TINA-TI Spice Model
SIMULATION MODEL Download
SNVMA10.ZIP (1 KB) - PSpice Model
SIMULATION MODEL Download
SNVMBT9.TSC (140 KB) - TINA-TI Reference Design
SIMULATION TOOL Download
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Features
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)
CALCULATION TOOL Download
Fly-Buck and Flyback Topology Selector
FLYBUCK-FLYBACK-DESIGN-CALC This tool helps a power supply engineer to select the right isolated DC-DC topology based on the specifications. Depending on the topology chosen, the calculator also recommends the right IC for the design.
Features
  • Features isolated topologies like Fly-Buck™, Fly-Buck-Boost, DCM and CCM Flyback
  • Capability to design up to 6 isolated outputs
  • Recommends ICs for desired application design
  • Incorporates loop compensation in designs
  • Compares efficiency, external component count and transformer currents for every topology (...)
CAD/CAE SYMBOL Download
SNVC023.ZIP (733 KB)

Reference designs

Many TI reference designs include the LM3481 Use our reference design selection tool to review and identify designs that best match your application and parameters.

CAD/CAE symbols

Package Pins Download
VSSOP (DGS) 10 View options

Ordering & quality

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  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring

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