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LM5126A-Q1

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Automotive, 42V VIN, 2.2MHz single-phase boost controller with VOUT tracking

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Data sheet

LM5126A-Q1

ACTIVE
Data sheet Order now

Product details

Rating Automotive Topology Boost Controller Vin (max) (V) 45 Vin (min) (V) 2.5 Vout (max) (V) 60 Vout (min) (V) 6 Control mode current mode control Features Adjustable current limit, Adjustable soft start, Adjustable switching frequency, Analog current monitor, Automatic Light Load Management, Automotive load dump, Bypass Mode, Chip-enable control pin, Cycle-by-cycle overcurrent protection, External Sync, Fixed PWM Mode, Overcurrent protection with adjustable delay, Power good, Programmable dead time, Spread Spectrum, Tracking EMI features Frequency Dithering, Spread Spectrum Duty cycle (max) (%) 99.2 Iq (typ) (A) 0.00025 TI functional safety category Functional Safety-Capable Operating temperature range (°C) -40 to 150
Rating Automotive Topology Boost Controller Vin (max) (V) 45 Vin (min) (V) 2.5 Vout (max) (V) 60 Vout (min) (V) 6 Control mode current mode control Features Adjustable current limit, Adjustable soft start, Adjustable switching frequency, Analog current monitor, Automatic Light Load Management, Automotive load dump, Bypass Mode, Chip-enable control pin, Cycle-by-cycle overcurrent protection, External Sync, Fixed PWM Mode, Overcurrent protection with adjustable delay, Power good, Programmable dead time, Spread Spectrum, Tracking EMI features Frequency Dithering, Spread Spectrum Duty cycle (max) (%) 99.2 Iq (typ) (A) 0.00025 TI functional safety category Functional Safety-Capable Operating temperature range (°C) -40 to 150
VQFN (RHB) 32 25 mm² 5 x 5
  • AEC-Q100 qualified for automotive applications
    • Temperature grade 1: TA = –40°C to +125°C
  • Functional Safety-Capable
  • Input voltage 4.5V to 42V
    • Minimum 2.5V for V(BIAS) ≥4.5V or VOUT ≥6V
  • Output voltage 6V to 60V
    • 2% accuracy, internal feedback resistors
    • Bypass operation for VI > VOUT
    • Dynamic output voltage tracking
      • Digital PWM tracking (DTRK)
      • Analog tracking (ATRK)
    • Overvoltage protection (64V, 50V, 35V, 28.5V)
  • Low shutdown IQ of 2µA
  • Low operating IQ of 1mA
  • 3-phase operation with LM5125A-Q1
  • Switching frequency from 100kHz to 2.2MHz
    • Synchronization to external clock (SYNCIN)
    • Dynamically selectable switching modes (FPWM, diode emulation)
    • Spread spectrum (DRSS)
  • Selectable dead time (14ns to 200ns)
  • Current sense resistor or DCR sensing
  • Average inductor current monitor
  • Average input current limit
    • Programmable current limit
    • Selectable delay time
  • Power good indicator
  • Programmable VI undervoltage lockout (UVLO)
  • Lead-less QFN-32 packable with wettable flanks
  • AEC-Q100 qualified for automotive applications
    • Temperature grade 1: TA = –40°C to +125°C
  • Functional Safety-Capable
  • Input voltage 4.5V to 42V
    • Minimum 2.5V for V(BIAS) ≥4.5V or VOUT ≥6V
  • Output voltage 6V to 60V
    • 2% accuracy, internal feedback resistors
    • Bypass operation for VI > VOUT
    • Dynamic output voltage tracking
      • Digital PWM tracking (DTRK)
      • Analog tracking (ATRK)
    • Overvoltage protection (64V, 50V, 35V, 28.5V)
  • Low shutdown IQ of 2µA
  • Low operating IQ of 1mA
  • 3-phase operation with LM5125A-Q1
  • Switching frequency from 100kHz to 2.2MHz
    • Synchronization to external clock (SYNCIN)
    • Dynamically selectable switching modes (FPWM, diode emulation)
    • Spread spectrum (DRSS)
  • Selectable dead time (14ns to 200ns)
  • Current sense resistor or DCR sensing
  • Average inductor current monitor
  • Average input current limit
    • Programmable current limit
    • Selectable delay time
  • Power good indicator
  • Programmable VI undervoltage lockout (UVLO)
  • Lead-less QFN-32 packable with wettable flanks

The LM5126A-Q1 is a synchronous boost controller. The device provides a regulated output voltage for lower or equal input voltage also supporting VI to VOUT bypass mode to save power. The device can be stacked in combination with LM5125A-Q1 for 3-phase operation.

Dynamically program VOUT using the analog or digital ATRK/DTRK function. VI is supported down to 2.5V after startup as the internal VCC supply is automatically switched from VBIAS to VOUT for VBIAS < 4.5V. The fixed switching frequency is set between 100kHz and 2.2MHz through a resistor on the RT-pin or the SYNCIN clock. The switching modes FPWM or diode emulation can be changed during operation.

The implemented protections peak current limit, average input current limit, average inductor current monitor, overvoltage and undervoltage protection, and the thermal shutdown protect the device and the application.

The LM5126A-Q1 is a synchronous boost controller. The device provides a regulated output voltage for lower or equal input voltage also supporting VI to VOUT bypass mode to save power. The device can be stacked in combination with LM5125A-Q1 for 3-phase operation.

Dynamically program VOUT using the analog or digital ATRK/DTRK function. VI is supported down to 2.5V after startup as the internal VCC supply is automatically switched from VBIAS to VOUT for VBIAS < 4.5V. The fixed switching frequency is set between 100kHz and 2.2MHz through a resistor on the RT-pin or the SYNCIN clock. The switching modes FPWM or diode emulation can be changed during operation.

The implemented protections peak current limit, average input current limit, average inductor current monitor, overvoltage and undervoltage protection, and the thermal shutdown protect the device and the application.
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Type Title Date
* Data sheet LM5126A-Q1, Wide-VIN, Single-Phase, Boost Controller with VOUT Tracking datasheet PDF | HTML 26 Nov 2025
Functional safety information LM5126A-Q1 and LM51261A-Q1 Functional Safety FIT Rate, FMD and Pin FMA PDF | HTML 24 Oct 2025

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Evaluation board

LM5126AEVM-BST — LM5126A evaluation module

The LM5126AEVM-BST evaluation module showcases the features and performance of the LM5126A-Q1 wide input voltage synchronous boost controller. This EVM is designed for ease of configuration, enabling the user to evaluate different conditions on the module. The standard configuration is designed to (...)
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LM5126A-BOOST-CALC — LM5126A Boost Controller Quick Start Calculator

Design calculator for LM5126A
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  • LM5126A-Q1 — Automotive, 42V VIN, 2.2MHz single-phase boost controller with VOUT tracking
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