LM5149

ACTIVE

80-V synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter

Product details

Vin (min) (V) 3.5 Vin (max) (V) 80 Iout (max) (A) 20 Operating temperature range (°C) -40 to 150 Control mode current mode Rating Catalog Vout (min) (V) 0.8 Vout (max) (V) 55 Iq (typ) (A) 0.0000095 Duty cycle (max) (%) 99
Vin (min) (V) 3.5 Vin (max) (V) 80 Iout (max) (A) 20 Operating temperature range (°C) -40 to 150 Control mode current mode Rating Catalog Vout (min) (V) 0.8 Vout (max) (V) 55 Iq (typ) (A) 0.0000095 Duty cycle (max) (%) 99
VQFN (RGY) 24 19.25 mm² 5.5 x 3.5
  • Functional Safety-Capable
  • Two integrated EMI mitigation mechanisms
    • Active EMI Filter for enhanced EMI performance at lower frequencies
    • Selectable dual random spread spectrum (DRSS) for enhanced EMI performance across low and high-frequency bands
    • EMI reduced by an average of 25 dBµV
    • Reduces the external differential-mode input filter size by 50% and lowers systems cost
    • Optimized for CISPR 32 Class B requirements
  • Versatile synchronous buck DC/DC controller
    • Wide input voltage range of 3.5 V to 80 V
    • 1% accurate, fixed 3.3 V, 5 V, 12 V, or adjustable output from 0.8 V to 55 V
    • 150°C maximum junction temperature
    • Shutdown mode current: 2.3 µA
    • No-load sleep current: 9.5 µA
    • Stackable up to two phases
    • Advanced dropout with frequency foldback
  • Switching frequency from 100 kHz to 2.2 MHz
    • SYNC in and SYNC out capability
  • Inherent protection features for robust design
    • Internal hiccup-mode overcurrent protection
    • ENABLE and PGOOD functions
    • VCC, VDDA, and gate-drive UVLO protection
    • Internal or external loop compensation
    • Thermal shutdown protection with hysteresis
  • Create a custom design using the LM5149 with WEBENCH Power Designer
  • Functional Safety-Capable
  • Two integrated EMI mitigation mechanisms
    • Active EMI Filter for enhanced EMI performance at lower frequencies
    • Selectable dual random spread spectrum (DRSS) for enhanced EMI performance across low and high-frequency bands
    • EMI reduced by an average of 25 dBµV
    • Reduces the external differential-mode input filter size by 50% and lowers systems cost
    • Optimized for CISPR 32 Class B requirements
  • Versatile synchronous buck DC/DC controller
    • Wide input voltage range of 3.5 V to 80 V
    • 1% accurate, fixed 3.3 V, 5 V, 12 V, or adjustable output from 0.8 V to 55 V
    • 150°C maximum junction temperature
    • Shutdown mode current: 2.3 µA
    • No-load sleep current: 9.5 µA
    • Stackable up to two phases
    • Advanced dropout with frequency foldback
  • Switching frequency from 100 kHz to 2.2 MHz
    • SYNC in and SYNC out capability
  • Inherent protection features for robust design
    • Internal hiccup-mode overcurrent protection
    • ENABLE and PGOOD functions
    • VCC, VDDA, and gate-drive UVLO protection
    • Internal or external loop compensation
    • Thermal shutdown protection with hysteresis
  • Create a custom design using the LM5149 with WEBENCH Power Designer

The LM5149 is a 80-V, ultra-low IQ synchronous buck DC/DC controller for high-current, single-output applications. The controller uses a peak current-mode control architecture for easy loop compensation, fast transient response, and excellent load and line regulation. The LM5149 can be set up in interleaved dual-phase mode with accurate current sharing for high-current applications. The device can operate with VIN as low as 3.5 V, at nearly 100% duty cycle if needed.

The LM5149 has two unique EMI reduction features: active EMI filter and dual random spread spectrum (DRSS). The active EMI filter senses any noise or ripple voltage on the DC input bus and injects an out-of-phase cancellation signal to reduce the disturbance. DRSS combines low-frequency triangular and high-frequency randomized modulations to mitigate EMI across lower and higher frequency bands, respectively. This hybrid technique aligns with the multiple resolution bandwidth (RBW) settings specified in industry-standard EMC tests.

Additional features of the LM5149 include 150°C maximum junction temperature operation, user-selectable diode emulation for lower current consumption at light-load conditions, open-drain power-good flag for fault reporting and output monitoring, precision enable input, monotonic start-up into prebiased load, integrated VCC bias supply regulator and bootstrap diode, internal 3-ms soft-start time, and thermal shutdown protection with automatic recovery.

The LM5149- controller comes in a 3.5-mm × 5.5-mm thermally enhanced, 24-pin VQFN package with an exposed pad to aid in thermal dissapation.

The LM5149 is a 80-V, ultra-low IQ synchronous buck DC/DC controller for high-current, single-output applications. The controller uses a peak current-mode control architecture for easy loop compensation, fast transient response, and excellent load and line regulation. The LM5149 can be set up in interleaved dual-phase mode with accurate current sharing for high-current applications. The device can operate with VIN as low as 3.5 V, at nearly 100% duty cycle if needed.

The LM5149 has two unique EMI reduction features: active EMI filter and dual random spread spectrum (DRSS). The active EMI filter senses any noise or ripple voltage on the DC input bus and injects an out-of-phase cancellation signal to reduce the disturbance. DRSS combines low-frequency triangular and high-frequency randomized modulations to mitigate EMI across lower and higher frequency bands, respectively. This hybrid technique aligns with the multiple resolution bandwidth (RBW) settings specified in industry-standard EMC tests.

Additional features of the LM5149 include 150°C maximum junction temperature operation, user-selectable diode emulation for lower current consumption at light-load conditions, open-drain power-good flag for fault reporting and output monitoring, precision enable input, monotonic start-up into prebiased load, integrated VCC bias supply regulator and bootstrap diode, internal 3-ms soft-start time, and thermal shutdown protection with automatic recovery.

The LM5149- controller comes in a 3.5-mm × 5.5-mm thermally enhanced, 24-pin VQFN package with an exposed pad to aid in thermal dissapation.

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Technical documentation

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Type Title Date
* Data sheet LM5149 80-V, Synchronous, Buck, DC/DC Controller with Ultra-Low IQ and Integrated Active EMI Filter datasheet (Rev. A) PDF | HTML 24 Jan 2023
Application note How to Implement a Simple Constant Current Regulation Scheme to a PCM Based Buck PDF | HTML 16 Aug 2023
Functional safety information LM5149 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA PDF | HTML 16 Dec 2022
User guide LM25149-Q1 EVM User's Guide (Rev. A) PDF | HTML 29 Apr 2022

Design & development

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

Evaluation board

LM25149-Q1EVM-2100 — LM25149-Q1 5.5-V to 36-V, low IQ, synchronous buck DC/DC controller evaluation module

The LM25149-Q1EVM-2100 high-density evaluation module (EVM) is designed to showcase the performance of the LM25149-Q1 high-performance, automotive synchronous buck DC/DC buck controller. It operates over a wide input voltage range of 5.5 V to 36 V to deliver a fixed 5-V output with better than 1% (...)
User guide: PDF | HTML
Not available on TI.com
Evaluation board

LM5149-Q1EVM-400 — LM5149-Q1 evaluation module, 72-V, low-IQ, synchronous buck DC/DC controller with active EMI filter

The LM5149-Q1EVM-400 high-density evaluation module (EVM) is designed to showcase the performance of the LM5149-Q1 high-performance, automotive, synchronous buck DC/DC buck controller. The EVM operates over a wide input voltage range of 15 V to 72 V to deliver a fixed 12-V output with better than (...)

User guide: PDF | HTML
Not available on TI.com
Simulation model

LM5149-Q1 PSPICE Transient Model

SNVMCB8.ZIP (87 KB) - PSpice Model
Calculation tool

LM5149-LM25149DESIGN-CALC LM25149 Design Calculation Tool

Welcome to the quickstart design tool for the LM5149, LM5149-Q1 and LM25149, LM25149-Q1. This standalone tool facilitates and assists the power supply engineer with the design of a DC/DC buck regulator based on the above controller family. As such, the user can expeditiously arrive at an optimized (...)
Supported products & hardware

Supported products & hardware

Products
AC/DC & DC/DC controllers (external FET)
LM25149 42-V synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter LM25149-Q1 42-V automotive synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter LM5149 80-V synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter LM5149-Q1 80-V automotive synchronous buck DC/DC controller with ultra-low IQ and integrated active EMI filter
Hardware development
Evaluation board
LM25149-Q1EVM-2100 LM25149-Q1 5.5-V to 36-V, low IQ, synchronous buck DC/DC controller evaluation module
PCB layout

LM25149-Q1EVM-2100 PCB Layout Files

SNVR501.ZIP (1990 KB)
Package Pins Download
VQFN (RGY) 24 View options

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  • Ongoing reliability monitoring
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