Home Power management AC/DC & DC/DC controllers (external FET)
Home
Power management
AC/DC & DC/DC controllers (external FET)

LM5121

ACTIVE

3-65V Wide Vin, Current Mode Synchronous Boost with Disconnection Switch Control

Order now
Data sheet

LM5121

ACTIVE
Data sheet Order now

Product details

Vin (min) (V) 3 Vin (max) (V) 65 Operating temperature range (°C) -40 to 125 Control mode current mode Topology Boost, Flyback, Forward, SEPIC Rating Catalog Vout (min) (V) 3 Vout (max) (V) 100 Features Adjustable current limit, Enable, Frequency synchronization, Light Load Efficiency, Synchronous Rectification, UVLO adjustable Iq (typ) (µA) 4000 Duty cycle (max) (%) 100
Vin (min) (V) 3 Vin (max) (V) 65 Operating temperature range (°C) -40 to 125 Control mode current mode Topology Boost, Flyback, Forward, SEPIC Rating Catalog Vout (min) (V) 3 Vout (max) (V) 100 Features Adjustable current limit, Enable, Frequency synchronization, Light Load Efficiency, Synchronous Rectification, UVLO adjustable Iq (typ) (µA) 4000 Duty cycle (max) (%) 100
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.
filter Find other AC/DC & DC/DC controllers (external FET)
Download View video with transcript Video

Technical documentation

star =Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 7
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
Application note Designing Fault Protection Circuits Using Wide VIN LM5121 12 Jan 2015
White paper How to design boost, SEPIC or flyback regulators with wide VIN power ICs 29 Jul 2014
Application note Practical Feedback Loop Analysis for Current-Mode Boost Converter 07 Mar 2014
Application note Automated Frequency Response Analyzer 09 Oct 2013
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
Download
Simulation model

LM5121 TINA-TI Transient Reference Design

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

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

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

LM5121 Unencrypted PSpice Transient Model

SNVM962.ZIP (7 KB) - PSpice Model
Download
Reference designs

PMP11422 — High Density 72W Battery Powered Synchronous Boost Reference Design

PMP11422 is a synchronous boost power supply using the LM5121 controllers. The design accepts an input voltage of 5Vin to 8.6Vin, and boosts a 12Vout rail capable of sourcing 6A continuous current. The LM5121 integrates an input disconnection switch feature which allows boost short circuit (...)
Test report: PDF
Schematic: PDF
Reference designs

PMP8673 — 150W Boost Converter with LM5121 Reference Design

The PMP8673 reference design is a synchronous boost converter optimized for high efficiency while maintaining a small form factor. This reference design has a voltage input range of 34.5-37.5V (35V nominal) and provides an output voltage of 55.5V. The synchronous boost topology enables efficiencies (...)
Test report: PDF
Schematic: PDF
Reference designs

PMP9297 — 150W Dual Channel Synchronous Boost for Gan audio applications

PMP9297 is a dual channel synchronous boost for GaN audio amplifier applications. It converts 35V input to an adjustable 38V to 55V output at 150W per channel. The solution size fits in a 45mm x 34 mm board area. Additional input and output bulk capacitors are included outside of the solution size (...)
Test report: PDF
Schematic: PDF
Package Pins CAD symbols, footprints & 3D models
HTSSOP (PWP) 20 Ultra Librarian
TI's Standard Terms and Conditions for Evaluation Items apply.

Ordering & quality

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

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

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. ​​​​​​​​​​​​​​

Videos