7.5-100V Wide Vin, 100mA Constant On-Time Synchronous Buck Regulator


Product details


Vin (Max) (V) 100 Vin (Min) (V) 7.5 Iout (Max) (A) 0.1 Features Synchronous Rectification Operating temperature range (C) -40 to 125 Regulated outputs (#) 1 Package type HSOP(8)/WSON(8) open-in-new Find other Isolated DC/DC converters & modules

Package | Pins | Size

HSOIC (DDA) 8 19 mm² 4.9 x 3.9 WSON (NGU) 8 16 mm² 4 x 4 open-in-new Find other Isolated DC/DC converters & modules


  • Wide 7.5-V to 100-V input range
  • Integrated 100-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
  • Packages:
    • 8-Pin WSON
    • 8-Pin SO PowerPAD
  • Create a custom design using the LM5019 with the WEBENCH Power Designer
open-in-new Find other Isolated DC/DC converters & modules


The LM5019 is a 100-V, 100-mA synchronous step-down regulator with integrated high-side and low-side MOSFETs. The constant-on-time (COT) control scheme employed in the LM5019 requires no loop compensation, provides excellent transient response, and enables very low 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 start-up 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 LM5019 device is available in WSON-8 and SO PowerPAD-8 plastic packages.

open-in-new Find other Isolated DC/DC converters & modules

Technical documentation

star = Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 19
Type Title Date
* Data sheet LM5019 100-V, 100-mA Constant On-Time Synchronous Buck / Fly-Buck™ Regulator datasheet (Rev. H) Aug. 12, 2021
Selection guide Buck Converter Quick Reference Guide (Rev. B) Apr. 08, 2021
Functional safety information LM26420-Q1 Functional Safety FIT Rate and Failure Mode Distribution Feb. 17, 2020
White paper Valuing wide VIN, low EMI synchronous buck circuits for cost-driven, demanding a (Rev. A) Apr. 10, 2019
Application note Powering Drones With a Wide VIN DC-DC Converter (Rev. A) Feb. 05, 2019
Selection guide Power Management Guide 2018 (Rev. R) Jun. 25, 2018
Technical article Simplifying 100V wide VIN power conversion Nov. 11, 2016
Technical article Create a Fly-Buck™ converter in WEBENCH® Power Designer Oct. 09, 2015
White paper Designing isolated rails on the fly with Fly-Buck™ converters Sep. 29, 2015
Application note Fly-Buck(TM) converter provides EMC and isolation in PLC applications Jan. 29, 2015
Technical article Fly-Buck: Frequently Asked Questions (FAQs) Jan. 05, 2015
Application note AN-2292 Designing an Isolated Buck (Fly-Buck) Converter (Rev. C) Dec. 17, 2014
Technical article Powering Bipolar Rails with Wide-VIN Fly-Buck Converter Dec. 09, 2014
More literature Fly-Buck™ Solution Nov. 19, 2013
White paper Wide VIN power management ICs simplify white paper (Rev. A) Sep. 19, 2013
User guide AN-2204 LM5017 Isolated Supply Evaluation Board (Rev. B) Aug. 13, 2013
User guide AN-2240 LM5019 Isolated Evaluation Board (Rev. A) Apr. 30, 2013
User guide LM5019 Buck Evaluation Board (Rev. A) Apr. 30, 2013
More literature High-Voltage PoL Power Solutions Jan. 30, 2012

Design & development

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

Hardware development

document-generic User guide
This motherboard is the base board for the PSE Controller ecosystem. The octal channel, TPS23882, IEEE 802.3bt ready PoE PSE controller can be evaluated by using the motherboard (BOOST-PSEMTHR8-097) and TPS23882EVM daughter card (TPS23882EVM-008) (sold separately). The full PoE Evaluation ecosystem (...)
  • 8 port PoE PSE system
  • Highly flexible system with configurable GUI and host interface
  • Low-cost solution
  • IEEE 802.3bt ready
document-generic User guide
The LM5019 evaluation board provides the designer with a fully functional buck regulator employing the constant on-time (COT) operating principle. The evaluation board provides a 10V output over an input range of 12.5V to 100V.
  • Input Voltage Range: 12.5V to 100V
  • Output Voltage: 10V
  • Output Current 100 mA
  • Nominal Switching Frequency ~ 440 kHz
  • Measured Efficiency: 88.4% at 300 mA and VIN = 24V
  • Board Size 5.5 cm x 4.5 cm
document-generic User guide
The LM5019ISOEVAL evaluation board facilitates evaluation of the LM5019 100V, 100mA Constant On-Time Synchronous Buck Regulator. An isolated bias supply is implemented in this evaluation board with the LM5019 the Constant On-Time regulator. The LM5019 regulator integrates both the high and low side (...)
  • Input Voltage Range: 20V to 100V
  • Primary Output Voltage: 10V
  • Secondary (Isolated) Output Voltage: 9.5V
  • Maximum Load Current (Primary and Secondary): 100 mA
  • Maximum Power Output: 1W
  • Nominal Switching Frequency 750 kHz efficiency (FIN = 24V, IOUT2 = 100mA
  • 70% Board Size: 2 inch x 2 inch

Design tools & simulation

SNVM045.ZIP (39 KB) - PSpice Model
SNVMAM4.ZIP (2 KB) - PSpice Model
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 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 (...)
LM5019 Quick Start Calculator
LM5019QUICK-CALC LM5019 Quick Start Calculator is an easy to use excel based design tool for LM5019 based buck converter design. The design tool has all the design equations embedded and an example default design. The user can modify the design input parameters such as the input voltage range, output voltage, load (...)
SNVC056.ZIP (227 KB)

Reference designs

Solar MPPT Charge Controller Reference Design
TIDA-00120 This design is a 20A Maximum Power Point Tracking (MPPT) solar charge controller created for solar panel inputs corresponding to 12V and 24V panels. The design is targeted for small and medium power solar charger solutions and is capable of operating with 12V/24V panels and 12V/24V batteries up to (...)
document-generic Schematic document-generic User guide
Design files
Type 2 PoE PSE, 6kV Lightning Surge Reference Design
TIDA-01411 — This reference design provides lightning surge protection solution for Power over Ethernet (PoE) Power Sourcing Equipment (PSE) systems based on TI's TPS23861 PSE controller. The need for implementing such protection will normally depend on the environment in which the PSE is intended to operate and (...)
document-generic Schematic
Low-Power Isolated Supply, Input range: 36V to 75V, Output: 10V @ 120mA, LM5017
PMP7798 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 (...)
document-generic Schematic
Flybuck Single Isolated Power Supply without Opto, 18 - 30V input, 24V @ 100mA Output
PMP7316 — The PMP7316 reference design uses the LM5017 to generate a 24V output at 100 mA. The inductor has reinforced isolation and the input voltage range is from 18V to 30V DC.
Design files
Flybuck Single Isolated Power Supply without Opto, 18 - 30V input, 24V @ 100mA Output
PMP7315 — The PMP7316 reference design uses the LM5017 to generate a 24V output at 100 mA. The inductor has reinforced isolation and the input voltage range is from 18V to 30V DC.
Design files

CAD/CAE symbols

Package Pins Download
SO PowerPAD (DDA) 8 View options
WSON (NGU) 8 View options

Ordering & quality

Information included:
  • RoHS
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring

Recommended products may have parameters, evaluation modules or reference designs related to this TI product.

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​