LM25149

ACTIVE

42-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) 42 Iout (max) (A) 30 Operating temperature range (°C) -40 to 150 Control mode current mode Topology Buck Controller Rating Catalog Vout (min) (V) 0.8 Vout (max) (V) 36 EMI features Active EMI filter, Spread Spectrum Features Adjustable current limit, Enable, Frequency synchronization, Load Disconnect, Phase Interleaving, Power good, Pre-Bias Start-Up, Spread Spectrum, Synchronous Rectification, UVLO adjustable Iq (typ) (µA) 9.5 Duty cycle (max) (%) 99 Number of phases 2
Vin (min) (V) 3.5 Vin (max) (V) 42 Iout (max) (A) 30 Operating temperature range (°C) -40 to 150 Control mode current mode Topology Buck Controller Rating Catalog Vout (min) (V) 0.8 Vout (max) (V) 36 EMI features Active EMI filter, Spread Spectrum Features Adjustable current limit, Enable, Frequency synchronization, Load Disconnect, Phase Interleaving, Power good, Pre-Bias Start-Up, Spread Spectrum, Synchronous Rectification, UVLO adjustable Iq (typ) (µA) 9.5 Duty cycle (max) (%) 99 Number of phases 2
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 42 V
    • 1% accurate, fixed 3.3-V, 5-V, 12-V, or adjustable output from 0.8 V to 36 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 LM25149 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 42 V
    • 1% accurate, fixed 3.3-V, 5-V, 12-V, or adjustable output from 0.8 V to 36 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 LM25149 with WEBENCH Power Designer

The LM25149 is a 42-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 LM25149 can be set up in interleaved dual-phase mode with accurate current sharing for high-current applications. It can operate with VIN as low as 3.5 V, at nearly 100% duty cycle if needed.

The LM25149 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 LM25149 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 LM25149 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 LM25149 is a 42-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 LM25149 can be set up in interleaved dual-phase mode with accurate current sharing for high-current applications. It can operate with VIN as low as 3.5 V, at nearly 100% duty cycle if needed.

The LM25149 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 LM25149 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 LM25149 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

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

LM25149-Q1 PSpice Transient Model

SNVMC96.ZIP (308 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 CAD symbols, footprints & 3D models
VQFN (RGY) 24 Ultra Librarian

Ordering & quality

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  • 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

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