2.2MHz wide VIN non-synchronous boost/SEPIC/flyback controller


Product details


Vin (Min) (V) 1.5 Vin (Max) (V) 45 Vout (Min) (V) 1.5 Vout (Max) (V) 300 Regulated outputs (#) 1 Switching frequency (Min) (kHz) 100 Switching frequency (Max) (kHz) 2200 Iq (Typ) (mA) 0.45 Features Adjustable Current Limit, Frequency Synchronization, Power Good, UVLO Adjustable Duty cycle (Max) (%) 93 TI functional safety category Functional Safety-Capable Rating Automotive Operating temperature range (C) -40 to 150 open-in-new Find other Boost controllers (external switch)

Package | Pins | Size

WSON (DSS) 12 6 mm² 3 x 2 open-in-new Find other Boost controllers (external switch)


  • AEC-Q100 qualified for automotive applications
    • Temperature grade 1: –40°C to +125°C TA
  • Functional Safety-Capable
    • Documentation available to aid functional safety system design
  • Wide input operating range for car and portable battery applications
    • 3.5-V to 45-V Operating range
    • 2.97-V to 16-V When BIAS = VCC
    • Minimum boost supply voltage 1.5 V when BIAS ≥ 3.5 V
    • Input transient protection up to 50 V
  • Minimized battery drain
    • Low shutdown current (IQ ≤ 2.6 µA)
    • Low operating current (IQ ≤ 480 µA)
  • Small solution size and low cost
    • Maximum switching frequency of 2.2 MHz
    • 12-Pin WSON package (3 mm × 2 mm) with wettable flanks
    • Integrated error amplifier allows primary-side regulation without optocoupler (flyback)
    • Minimized undershoot during cranking (start-stop application)
  • Higher efficiency with low-power dissipation
    • 100-mV ±7% Low current limit threshold
    • Strong 1.5-A peak standard MOSFET driver
    • Supports external VCC supply
  • Avoid AM band interference and crosstalk
    • Optional clock synchronization
    • Dynamically programmable switching frequency from 100 kHz to 2.2 MHz
  • Integrated protection features
    • Constant peak current limiting over input voltage
    • Optional hiccup mode short-circuit protection (see the Device Comparison Table)
    • Programmable line UVLO
    • OVP protection
    • Thermal shutdown
  • Accurate ±1% accuracy feedback reference
  • Programmable extra slope compensation
  • Adjustable soft start
  • PGOOD indicator
  • Create a custom design using the LM5155x with the WEBENCH® power designer

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The LM5155x-Q1 (LM5155-Q1 and LM51551-Q1) is a wide input range, non-synchronous boost controller that uses peak current mode control. The device can be used in boost, SEPIC, and flyback topologies.

The LM5155x-Q1 can start up from a 1-cell battery with a minimum of 2.97 V if the BIAS pin is connected to the VCC pin. It can operate with the input supply voltage as low as 1.5 V if the BIAS pin is greater than 3.5 V.

The internal VCC regulator also supports BIAS pin operation up to 45 V (50-V absolute maximum) for automotive load dump. The switching frequency is dynamically programmable with an external resistor from 100 kHz to 2.2 MHz. Switching at 2.2 MHz minimizes AM band interference and allows for a small solution size and fast transient response.

The device features a 1.5-A standard MOSFET driver and a low 100-mV current limit threshold. The device also supports the use of an external VCC supply to improve efficiency. Low operating current and pulse-skipping operation improve efficiency at light loads.

The device has built-in protection features such as cycle-by-cycle current limit, overvoltage protection, line UVLO, and thermal shutdown. Hiccup mode overload protection is available in the LM51551-Q1 device option. Additional features include low shutdown IQ, programmable soft start, programmable slope compensation, precision reference, power-good indicator, and external clock synchronization.

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Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 11
Type Title Date
* Datasheet LM5155x-Q1 2.2-MHz Wide Input Nonsynchronous Boost, SEPIC, Flyback Controller datasheet (Rev. D) Jun. 10, 2020
Application notes LM5155-Q1, LM51551-Q1 Functional Safety FIT Rate and Failure Mode Distribution Feb. 05, 2020
Technical articles How semiconductor technologies are changing automotive lighting roadmaps Oct. 23, 2019
Application notes How to design an isolated flyback using LM5155 Feb. 05, 2019
Technical articles Designing a smarter sunroof Jan. 10, 2019
Application notes How to Design a Boost Converter Using LM5155 Dec. 17, 2018
User guides LM5155EVM-BST User's Guide Dec. 11, 2018
Technical articles How to add overvoltage protection to a synchronous boost controller Sep. 17, 2018
User guides LM5155EVM-FLY User's Guide Aug. 02, 2018
User guides LM5155EVM-SEPIC User's Guide Aug. 02, 2018
Application notes Improve DC/DC Regulator EMI for Free with Optimized Power Stage Layout Nov. 13, 2017

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

The LM5155EVM-BST evaluation module showcases the features and performance of the LM5155, wide input non-synchronous boost controller. The standard configuration is designed to provide a regulate output of 24V at 2A from an input of 6V to 18V, switching at 440 kHz.

This EVM is designed for ease of (...)

  • Input voltage range: 6V to 18V
  • Output voltage 24V at 2A
  • 440kHz switching frequency
  • External clock synchronization
document-generic User guide
The LM5155EVM-FLY evaluation module showcases the features and performance of the LM5155 as a wide input non-synchronous flyback controller. The standard configuration is designed to provide a regulated output of 5V at 4A from an input of 18V to 36V, switching at 250 kHz. This evaluation module is (...)
  • Input voltage range: 18V to 36V
  • Isolated output voltage 5V at 4A
  • Switching frequency 250kHz
  • Two layer PCB with single sided component population
  • Hiccup mode short circuit protection
document-generic User guide
The LM5155EVM-SEPIC evaluation module showcases the features and performance of the LM5155 as wide input non-synchronous SEPIC controller. The standard configuration is designed to provide a regulated output of 12V at up to 2A from an input of 3V to 42V, switching at 2.2 MHz.
  • Input voltage range: 3V to 42V
  • Output voltage 12V, up to to 2A
  • Switching frequency 2.2 MHz
  • Two layer PCB with single sided component population

Design tools & simulation

SNVMBL2E.ZIP (238 KB) - PSpice Model
SNVMBV7.ZIP (52 KB) - TINA-TI Spice Model
SNVMBV8.TSC (1162 KB) - TINA-TI Reference Design
SNVMBY3A.ZIP (74 KB) - PSpice Model
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 (...)
  • 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
  • (...)
SNVC224.ZIP (3631 KB)
SNVC240.ZIP (5304 KB)

Reference designs

Many TI reference designs include the LM5155-Q1 Use our reference design selection tool to review and identify designs that best match your application and parameters.

CAD/CAE symbols

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WSON (DSS) 12 View options

Ordering & quality

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