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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open-in-new Find other Boost controllers (external switch)


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.

open-in-new Find other Boost controllers (external switch)

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
Functional safety information 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 note How to design an isolated flyback using LM5155 Feb. 05, 2019
Technical articles Designing a smarter sunroof Jan. 10, 2019
Application note How to Design a Boost Converter Using LM5155 Dec. 17, 2018
User guide LM5155EVM-BST User's Guide Dec. 11, 2018
Technical articles How to add overvoltage protection to a synchronous boost controller Sep. 17, 2018
User guide LM5155EVM-FLY User's Guide Aug. 02, 2018
User guide LM5155EVM-SEPIC User's Guide Aug. 02, 2018
Application note 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


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
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
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

SNVMBL2D.ZIP (217 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

Automotive dual stage (SEPIC + Linear) static LED driver module reference design for rear-lights
TIDA-020009 — This reference design details a solution for driving LEDs in an automotive rear-light application such as a rear combination lamp (RCL). It features linear LED drivers for different rear light light functions and the LED drivers are powered by a single ended primary inductance converter (SEPIC) LED (...)
document-generic Schematic
Automotive 8-W primary side regulated flyback with multi-output rails reference design
PMP30691 — This reference design provides an isolated automotive power supply that can be connected directly to the battery and is primarily targeted to supply gate driver in HEV/EV applications. It provides up to 8-W output power and offers a small footprint solution of 50.4 mm x 21.7 mm. The transformer for (...)
document-generic Schematic
High voltage inverting buck-boost converter reference design for ADAS applications
PMP22155 — This non-isolated design supplies an adjustable output voltage between -150-V and -250-V at 10-mA for LIDAR applications. It operates over an automotive input voltage range of 6-V to 40-V and accepts a control voltage from 0-V to 3-V for output voltage adjustment. Utilizing a single inductor and (...)
document-generic Schematic
Two output flyback power supply reference design for EV motor/generator inverter applications
PMP22170 — This flyback converter reference design supplies a non-isolated 5-V/0.25-A regulated output and an isolated 10-V/1.5-A unregulated output voltage. It uses primary-side regulation to reduce component count and operates over a wide automotive input voltage range of 5 V to 40 V. 
document-generic Schematic
Four-output, SEPIC converter-bias power supply reference design for solar panel applications
PMP21883 — This reference design supplies two non-isolated and two isolated output voltages. It references a regulated 3.3-V/0.25-A and an unregulated 12-V/0.05-A output on the primary-side, and it isolates two 12-V/0.025-A unregulated outputs.  The design operates over an input voltage range of 7 V to 45 (...)
document-generic Schematic
Automotive non-synchronous boost converter with dynamic output voltage scaling reference design
PMP30722 — This reference design showcases a non-synchronous boost converter with a 6-V to 18-V (36-Vpeak) input. The output voltage is programmable to 20 V-36 V using a 0-3.3 V PWM signal generated by a signal generator or MCU.
document-generic Schematic
Automotive SPD-SmartGlass™ driver reference design
TIDA-020013 — This reference design details how to drive various forms of electronically dimmable glass, including SPD-SmartGlass™ and APD Glass from a car battery. This illustrates how to make a DC/AC inverter using the LM5155-Q1 boost converter with a charge pump, two UCC27712-Q1 half bridge drivers, and (...)
document-generic Schematic
24-W nonsynchronous SEPIC pre-regulator reference design for automotive telematics control units
PMP30676 — This automotive pre-regulator reference design showcases a nonsynchronous single-ended primary-inductor converter (SEPIC), which covers an input voltage range of 6.0 V to 36 V. The output voltage is 12.0 V with a maximum load current of 2.0 A. The design can operate down to an input voltage of 4.5 V (...)
document-generic Schematic
30-V to 150-V Adjustable Output Voltage Boost Reference Design for LiDAR Applications
PMP21781 This reference design utilizes a non-synchronous boost controller to provide an adjustable output between 35 V and 150 V. It is capable of delivering a maximum of 85 mA of current to the load. This is an automotive design intended to power various applications, such as LiDAR systems, which require (...)
document-generic Schematic
Wide input range 3-W power reference design with four outputs
PMP30523 — This reference design is a tiny 3-W auxiliary power supply reference design driving four outputs – two of them isolated to power some drivers.  The wide input range is 6 V to 60 V, so 1:10 - here a discrete LDO is needed to expand BIAS voltage for controller LM51551. For lowest EMI, a (...)
document-generic Schematic

CAD/CAE symbols

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