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LM5121-Q1

ACTIVE

Automotive, 3-65-V wide VIN, current mode synchronous boost with disconnection switch control

Product details

Topology Boost, Flyback, Forward, SEPIC Vin (min) (V) 3 Vin (max) (V) 65 Vout (min) (V) 3 Vout (max) (V) 100 Regulated outputs (#) 1 Switching frequency (min) (kHz) 50 Switching frequency (max) (kHz) 1000 Iq (typ) (mA) 4 Features Enable, Frequency synchronization, Synchronous Rectification Duty cycle (max) (%) 100 Rating Automotive Operating temperature range (°C) -40 to 125 Type Controller Thermal resistance θJA (°C/W) 40
Topology Boost, Flyback, Forward, SEPIC Vin (min) (V) 3 Vin (max) (V) 65 Vout (min) (V) 3 Vout (max) (V) 100 Regulated outputs (#) 1 Switching frequency (min) (kHz) 50 Switching frequency (max) (kHz) 1000 Iq (typ) (mA) 4 Features Enable, Frequency synchronization, Synchronous Rectification Duty cycle (max) (%) 100 Rating Automotive Operating temperature range (°C) -40 to 125 Type Controller Thermal resistance θJA (°C/W) 40
HTSSOP (PWP) 20 41.6 mm² 6.5 x 6.4
  • AEC-Q100 Qualified with the following results:
    • Device Temperature Grade 1: –40°C to +125°C
      Ambient Operating Temperature Range
    • Device HBM ESD Classification Level 2
    • Device CDM ESD Classification Level C6
  • Maximum Input Voltage: 65 V
  • Min Input Voltage: 3.0 V (4.5 V for startup)
  • Output Voltage Up to 100 V
  • Bypass (VOUT = VIN) Operation
  • 1.2-V Reference with ±1.0% Accuracy
  • Free-Run/Synchronizable up to 1 MHz
  • Peak Current Mode Control
  • Robust Integrated 3-A Gate Drivers
  • Adaptive Dead-Time Control
  • Optional Diode Emulation Mode
  • Programmable Cycle-by-Cycle Current Limit
  • Programmable Line UVLO
  • Programmable Soft-Start
  • Thermal Shutdown Protection
  • Low Shutdown Quiescent Current: 9 µA
  • Programmable Slope Compensation
  • Programmable Skip Cycle Mode Reduces
    Standby Power
  • Supports External VCC Bias Supply Option
  • Load Disconnection in Shutdown Mode (True
    Shutdown)
  • Inrush Current Limiting
  • Hiccup Mode Short Circuit/Overload Protection
  • Circuit Breaker Function
  • Capable of Input Transient Suppression
  • Capable of Reverse Battery Protection
  • Thermally Enhanced 20-Pin HTSSOP
  • AEC-Q100 Qualified with the following results:
    • Device Temperature Grade 1: –40°C to +125°C
      Ambient Operating Temperature Range
    • Device HBM ESD Classification Level 2
    • Device CDM ESD Classification Level C6
  • Maximum Input Voltage: 65 V
  • Min Input Voltage: 3.0 V (4.5 V for startup)
  • Output Voltage Up to 100 V
  • Bypass (VOUT = VIN) Operation
  • 1.2-V Reference with ±1.0% Accuracy
  • Free-Run/Synchronizable up to 1 MHz
  • Peak Current Mode Control
  • Robust Integrated 3-A Gate Drivers
  • Adaptive Dead-Time Control
  • Optional Diode Emulation Mode
  • Programmable Cycle-by-Cycle Current Limit
  • Programmable Line UVLO
  • Programmable Soft-Start
  • Thermal Shutdown Protection
  • Low Shutdown Quiescent Current: 9 µA
  • Programmable Slope Compensation
  • Programmable Skip Cycle Mode Reduces
    Standby Power
  • Supports External VCC Bias Supply Option
  • Load Disconnection in Shutdown Mode (True
    Shutdown)
  • Inrush Current Limiting
  • Hiccup Mode Short Circuit/Overload Protection
  • Circuit Breaker Function
  • Capable of Input Transient Suppression
  • Capable of Reverse Battery Protection
  • Thermally Enhanced 20-Pin HTSSOP

The LM5121 is a synchronous boost controller intended for high-efficiency, high-power boost regulator applications. The control method is based upon peak current mode control. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting and ease of loop compensation.

The switching frequency is programmable up to 1 MHz. Higher efficiency is achieved using two robust N-channel MOSFET gate drivers with adaptive dead-time control. A user-selectable diode emulation mode enables discontinuous mode operation for improved efficiency at light load conditions.

The LM5121 provides disconnection switch control which completely disconnects the output from the input during an output short or a shutdown condition. During start-up sequence, inrush current is limited by the disconnection switch control.

An internal charge pump allows 100% duty cycle operation of the high-side synchronous switch (Bypass operation). Additional features include thermal shutdown, frequency synchronization, hiccup mode current limit and adjustable line undervoltage lockout.

The LM5121 is a synchronous boost controller intended for high-efficiency, high-power boost regulator applications. The control method is based upon peak current mode control. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting and ease of loop compensation.

The switching frequency is programmable up to 1 MHz. Higher efficiency is achieved using two robust N-channel MOSFET gate drivers with adaptive dead-time control. A user-selectable diode emulation mode enables discontinuous mode operation for improved efficiency at light load conditions.

The LM5121 provides disconnection switch control which completely disconnects the output from the input during an output short or a shutdown condition. During start-up sequence, inrush current is limited by the disconnection switch control.

An internal charge pump allows 100% duty cycle operation of the high-side synchronous switch (Bypass operation). Additional features include thermal shutdown, frequency synchronization, hiccup mode current limit and adjustable line undervoltage lockout.

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Technical documentation

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Type Title Date
* Data sheet LM5121/-Q1 Wide Input Synchronous Boost Controller with Disconnection Switch Control datasheet (Rev. C) PDF | HTML 14 Jun 2016
Analog Design Journal Designing the front-end DC/DC conversion stage to withstand automotive transient 18 Jan 2017
EVM User's guide LM5121EVM Evaluation Module 23 Aug 2013

Design & development

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

Evaluation board

LM5121EVM — Wide Vin Synchronous Boost Controller with Disconnection Switch Evaluation Module

The LM5121EVM evaluation module (EVM) provides the design engineer with a fully functional synchronous boost converter to evaluate the Texas Instruments LM5121 synchronous boost controller IC including disconnection switch control. The EVM provides 12V output at up to 2A current from a 3.0V (5.7V (...)
User guide: PDF
Not available on TI.com
Simulation model

LM5121 PSpice Transient Model (Rev. A)

SNVM505A.ZIP (115 KB) - PSpice Model
Simulation model

LM5121 TINA-TI Transient Reference Design

SNVMA48.TSC (192 KB) - TINA-TI Reference Design
Simulation model

LM5121 TINA-TI Transient Spice Model (Rev. A)

SNVMA47A.ZIP (53 KB) - TINA-TI Spice Model
Simulation model

LM5121 Unencrypted PSpice Transient Model

SNVM962.ZIP (7 KB) - PSpice Model
Simulation tool

PSPICE-FOR-TI — PSpice® for TI design and simulation tool

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 (...)
Reference designs

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This sensor fusion hub reference design allows the connection of up to four 2-megapixel cameras and up to four radar modules over coaxial cable. This design utilizes these coaxial cables to provide power, backchannel communication, and clock synchronization to the sensors. The two 4 Gbps FPD-Link (...)
Design guide: PDF
Schematic: PDF
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HTSSOP (PWP) 20 View options

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