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LM25018

ACTIVE

7.5-48V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator

A newer version of this product is available

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LM5168 ACTIVE 6-V to 120-V wide VIN, 300-mA DC-DC converter with Fly-Buck™ capability FPWM and PFM mode option and low IQ.

Product details

Device type Converters Topology Buck Vin (min) (V) 7.5 Vin (max) (V) 48 Vout (min) (V) 1.25 Vout (max) (V) 40 Iout (max) (A) 0.3 Features Synchronous rectification Operating temperature range (°C) -40 to 125 Regulated outputs (#) 1 Control mode Constant on-time (COT) Rating Catalog
Device type Converters Topology Buck Vin (min) (V) 7.5 Vin (max) (V) 48 Vout (min) (V) 1.25 Vout (max) (V) 40 Iout (max) (A) 0.3 Features Synchronous rectification Operating temperature range (°C) -40 to 125 Regulated outputs (#) 1 Control mode Constant on-time (COT) Rating Catalog
HSOIC (DDA) 8 29.4 mm² 4.9 x 6 WSON (NGU) 8 16 mm² 4 x 4
  • Wide 7.5-V to 48-V input range
  • Integrated 325-mA, high-side and low-side switches
  • No schottky required
  • Constant on-time control
  • No loop compensation required
  • Ultra-fast transient response
  • Nearly constant operating frequency
  • Intelligent peak current limit
  • Adjustable output voltage from 1.225 V
  • Precision 2% feedback reference
  • Frequency adjustable to 1 MHz
  • Adjustable undervoltage lockout
  • Remote shutdown
  • Thermal shutdown
  • Create a custom design using the LM25018 with the WEBENCH Power Designer
  • Wide 7.5-V to 48-V input range
  • Integrated 325-mA, high-side and low-side switches
  • No schottky required
  • Constant on-time control
  • No loop compensation required
  • Ultra-fast transient response
  • Nearly constant operating frequency
  • Intelligent peak current limit
  • Adjustable output voltage from 1.225 V
  • Precision 2% feedback reference
  • Frequency adjustable to 1 MHz
  • Adjustable undervoltage lockout
  • Remote shutdown
  • Thermal shutdown
  • Create a custom design using the LM25018 with the WEBENCH Power Designer

The LM25018 device is a 48-V, 325-mA synchronous step-down regulator with integrated high-side and low-side MOSFETs. The constant on-time (COT) control scheme employed in the LM25018 device requires no loop compensation, provides excellent transient response, and enables very high step-down ratios. The on-time varies inversely with the input voltage resulting in nearly constant frequency over the input voltage range. A high-voltage startup regulator provides bias power for internal operation of the IC and for integrated gate drivers.

A peak current-limit circuit protects against overload conditions. The undervoltage lockout (UVLO) circuit allows the input undervoltage threshold and hysteresis to be independently programmed. Other protection features include thermal shutdown and bias supply undervoltage lockout.

The LM25018 device is available in WSON-8 and SO Power PAD-8 plastic packages.

The LM25018 device is a 48-V, 325-mA synchronous step-down regulator with integrated high-side and low-side MOSFETs. The constant on-time (COT) control scheme employed in the LM25018 device requires no loop compensation, provides excellent transient response, and enables very high step-down ratios. The on-time varies inversely with the input voltage resulting in nearly constant frequency over the input voltage range. A high-voltage startup regulator provides bias power for internal operation of the IC and for integrated gate drivers.

A peak current-limit circuit protects against overload conditions. The undervoltage lockout (UVLO) circuit allows the input undervoltage threshold and hysteresis to be independently programmed. Other protection features include thermal shutdown and bias supply undervoltage lockout.

The LM25018 device is available in WSON-8 and SO Power PAD-8 plastic packages.

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Technical documentation

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Type Title Date
* Data sheet LM25018 48-V, 325-mA Constant On-Time Synchronous Buck/Fly-Buck™ Regulator datasheet (Rev. G) PDF | HTML 24 May 2021
Product overview Isolated Power Topologies for PLC I/O Modules and Other Low-Power Applications PDF | HTML 09 Nov 2022
Selection guide Buck Converter Quick Reference Guide (Rev. B) 08 Apr 2021
White paper Valuing wide VIN, low EMI synchronous buck circuits for cost-driven, demanding a (Rev. A) 10 Apr 2019
Application note Stability Analysis and Design of COT Type-3 Ripple Circuit 20 Mar 2019
Technical article Create a Fly-Buck™ converter in WEBENCH® Power Designer PDF | HTML 09 Oct 2015
Analog Design Journal Fly-Buck(TM) converter provides EMC and isolation in PLC applications 29 Jan 2015
Application note AN-2292 Designing an Isolated Buck (Fly-Buck) Converter (Rev. C) 17 Dec 2014
Product overview Fly-Buck™ Solution 19 Nov 2013
User guide LM25018 Isolated Buck (FlyBuck) User's Guide 20 Jun 2013
User guide AN-2237 LM5018 Buck Evaluation Board (Rev. A) 30 Apr 2013
User guide AN-2239 LM5018 Isolated Evaluation Board (Rev. A) 30 Apr 2013
User guide LM25018 Buck Evaluation Board 03 Apr 2013

Design & development

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

Evaluation board

LM5018EVAL — LM5018 Wide Vin Synchronous Buck Regulator Evaluation Board

The LM5018 evaluation board provides the design engineer with a fully functional buck regulator, employing the constant on-time (COT) operating principle. This evaluation board provides a 10V output over an input range of 12.5V to 100V.
User guide: PDF
Not available on TI.com
Evaluation board

LM5018ISOEVAL — LM5018 Isolated Bias Supply Evaluation Board

An isolated bias supply is implemented in this evaluation board with the LM5018 Constant-On-Time (COT) regulator. The LM5018 regulator integrates both the high and low side power switches essential for creating an isolated buck converter.
User guide: PDF
Not available on TI.com
Simulation model

LM25018 PSpice Transient Model

SNVM210.ZIP (40 KB) - PSpice Model
Simulation model

LM25018 Unencrypted PSpice Model

SNVM833.ZIP (2 KB) - PSpice Model
Calculation tool

FLYBUCK-FLYBACK-DESIGN-CALC Flybuck / Flyback Calculator

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.

Supported products & hardware

Supported products & hardware

Products
Boost converters (integrated switch)
LM2577 3.5-V to 40-V, 3-A low component count step-up regulator LM2585 4-V to 40-V, 3-A step-up wide VIN flyback regulator LM2586 4-V to 40-V, 3-A step-up wide VIN flyback regulator with frequency synchronization LM2587 4V to 40V, 5A Step-Up Wide Vin Flyback Regulator LM2588 4-V to 40-V, 5-A step-up wide VIN flyback regulator with frequency synchronization LM2621 1.2V to 14V input voltage, 1A load current, step-up DC-DC LM2623 0.8V to 14V input voltage, 2A load current, step-up DC-DC LM2623-Q1 0.8-V to 14-V input voltage, 2-A load current, step-up DC/DC, AEC-Q100 qualified LM2735 520kHz/1.6MHz space efficient boost and SEPIC DC-DC regulator LM2735-Q1 520-kHz, 1.6-MHz space efficient boost and SEPIC DC/DC regulator, AEC-Q100 qualified LM3578A 2-V to 40-VIN switching regulators in buck, boost, terminal, depending upon the application LM5000 3.1-40V Wide Vin, 2A Current Mode Non-Synchronous Boost Regulator LM5001 3.1-75V Wide Vin, 1A Current Mode Non-Synchronous Switch Mode Regulator LM5001-Q1 3.1-V to 75-V wide VIN, 1-A current mode non-synchronous switch mode regulator LM5002 3.1-75V Wide Vin, 0.5A Current Mode Boost, Flyback, Sepic Converter LM78S40 1.5A Adjustable Step Up, Step Down or Inverting Regulator TPS55340 5-A, 40-V, wide VIN boost, flyback, & SEPIC converter TPS55340-EP Enhanced integrated, 5-A, 40-V wide input range boost/SEPIC/flyback DC/DC regulator TPS55340-Q1 Integrated, 5-A 40-V wide input range boost/SEPIC/flyback DC/DC regulator, AEC-Q100 qualified TPS61175 3-A ,40V High Voltage Boost Converter with Soft-start and Programmable Switching Frequency TPS61175-Q1 3-A, 40-V high voltage boost converter with soft-start and programmable switching frequency
Buck converters (integrated switch)
LM5015 4.25-75V, Monolithic Two-Switch Forward DC-DC Regulator
Isolated DC/DC converters & modules
LM25017 7.5-48V Wide Vin, 650mA Constant On-Time Synchronous Buck Regulator LM25018 7.5-48V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator LM25019 7.5-48V Wide Vin, 100mA Constant On-Time Synchronous Buck Regulator LM34925 7.5-100V Wide Vin, 100mA Integrated Secondary Bias Regulator for Isolated DC/DC Converters LM34926 7.5-100V Wide Vin, 300mA Integrated Secondary Bias Regulator for Isolated DC/DC Converters LM34927 7.5-100V Wide Vin, 600mA Integrated Secondary Bias Regulator for Isolated DC/DC Converters LM5017 7.5-100V Wide Vin, 600mA Constant On-Time Synchronous Buck Regulator LM5018 7.5-100V Wide Vin, 300mA Constant On-Time Synchronous Buck Regulator LM5019 7.5-100V Wide Vin, 100mA Constant On-Time Synchronous Buck Regulator LM5160 LM5160 wide input 65V, 2A synchronous buck/Fly-Buck™ converter LM5160-Q1 Wide Input 65V, 2A Synchronous Buck / Fly-Buck™ Converter LM5160A LM5160A Wide Input 65V, 2A Synchronous Buck / Fly-Buck™ Converter LM5161 Wide Input 4.5-V to 100-V, 1-A Synchronous Buck / Fly-Buck Converter TPS55010 2.95V To 6V Input, 2W, Isolated DC/DC Converter with Integrated FETS
Boost controllers (external switch)
LM3017 High Efficiency Low-Side Controller with True Shutdown LM3478 2.97~40V Wide Input Range Boost/SEPIC/Flyback DC-DC Controller LM3478Q-Q1 40-V wide VIN low-side N-channel controller for switching regulators with 10-µA shutdown current LM3481 2.97V to 48V High-Efficiency Controller for Boost, SEPIC and Flyback LM3481-Q1 2.97-V to 48-V high-efficiency controller for boost, SEPIC and flyback, AEC-Q100 qualified LM3488 2.97V to 40V Wide Vin Low-Side N-Channel Controller for Switching Regulators LM3488Q-Q1 40-V wide VIN low-side N-channel controller for switching regulators with 5-µA shutdown current LM5020 13-100V Wide Vin, Current Mode PWM Boost, Flyback, Sepic Controller LM5022 6-60V Wide Vin, current mode boost, SEPIC and Flyback controller TL1451 Dual Pulse-Width-Modulation Control Circuit TL1451A 3.6V to 50V dual channel controller with Wide input voltage range TL1451A-EP Enhanced Product Dual Pulse-Width-Modulation Control Circuits TL1451A-Q1 3.6-V to 50-V dual-channel PWM controller, AEC-Q100 qualified TL5001 PWM Controller with wide input range, with ±5% tolerance on reference, operation –20°C to 85°C TL5001A PWM Controller with wide input range, with ±3% tolerance on reference, operation –20°C to 85°C TL5001A-Q1 PWM Controller with wide input range, with ±3% tolerance on reference, operation –20°C to 85°C TL5001M PWM Controller with wide input range, with ±5% tolerance on reference, operation –55°C to 125°C TPS40210-Q1 4.5-V to 52-V wide input range current mode boost controller with 700-mV reference voltage TPS40211-Q1 4.5-V to 52-V wide input range current mode boost controller with 260-mV reference voltage TPS43000 Multi-Topology (buck, boost, sepic) High Frequency DC/DC Controller UC2572 Negative output Flyback pulse width modulator
PWM controllers
LM3524D 40V, 0.2A 350KHz PWM controller
Reference designs

TIDA-01093 — Industrial Battery Management Module for 20S Applications Reference Design

High serial cell count battery (>15s) systems are becoming more and more common for industrial applications. These applications are cost sensitive and require a simple solution that includes monitoring, protection, and control or even SOC (State of Charge) information rather than only basic (...)
Design guide: PDF
Schematic: PDF
Reference designs

PMP7798 — Low-Power Isolated Supply, Input range: 36V to 75V, Output: 10V @ 120mA, LM5017

Based on the Wide VIN COT Sync Buck regulator LM5017, this FlyBuck circuit provides excellent regulation for two isolated outputs and one non-isolated output. Compared with a conventional Flyback circuit, this design features a smaller board size and minimized BOM without the need for an (...)
Test report: PDF
Schematic: PDF
Reference designs

PMP4412 — 24Vin, +5Vout, 1W Isolated SIP DC/DC Module Reference Design

The PMP4412 is a 24Vin +5Vout, 1W reference design module which is implemented in an industry-standard SIP pinout. It includes a constant on-time synchronous Flybuck controller LM25018. The solution has high efficiency, good line and load regulation with 1,500V DC isolation. The power module was (...)
Test report: PDF
Schematic: PDF
Reference designs

PMP4413 — 24Vin, ±15Vout, 1W Isolated SIP DC/DC Module Reference Design

The PMP4413 is a 24Vin ±15Vout, 1W reference design module which is implemented in an industry standard SIP pinout. It includes a constant on-time synchronous Flybuck controller LM25018. The solution has high efficiency, good line and load regulation with 1,500V DC isolation. The power (...)
Test report: PDF
Schematic: PDF
Reference designs

PMP4401 — 12Vin, ±5Vout, 1W Isolated SIP DC/DC module - Reference Design

The PMP4401 is a 12Vin, ±5Vout, 1W reference design module which is implemented in an industry standard SIP pinout.  It includes a constant on-time synchronous Fly-Buck controller LM25018.  The solution has high efficiency and good line and load regulation with 1,500V DC (...)
Test report: PDF
Schematic: PDF
Reference designs

PMP4394 — 24Vin, +/-5V, 1W Isolated SIP DC/DC module - Reference Design

PMP4394 is a 24Vin, +/-5V, 1W reference design which is implemented in the standard industrial SIP pinout.  It includes a constant on-time synchronous Fly-Buck controller LM25018.  The solution has high efficiency, good line, load regulation with 1500V DC isolation.  The power module (...)
Test report: PDF
Schematic: PDF
Package Pins Download
HSOIC (DDA) 8 View options
WSON (NGU) 8 View options

Ordering & quality

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  • Ongoing reliability monitoring

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