Product details

Vin (Min) (V) 3 Vin (Max) (V) 20 Vout (Min) (V) 0.6 Vout (Max) (V) 19 Iout (Max) (A) 30 Iq (Typ) (uA) 3500 Switching frequency (Min) (kHz) 200 Switching frequency (Max) (kHz) 1200 Features Enable, Frequency Synchronization, Power Good, Pre-Bias Start-Up, Remote Sense, Synchronous Rectification, Tracking Operating temperature range (C) -40 to 125 Regulated outputs (#) 1 Number of phases 1 Rating Catalog
Vin (Min) (V) 3 Vin (Max) (V) 20 Vout (Min) (V) 0.6 Vout (Max) (V) 19 Iout (Max) (A) 30 Iq (Typ) (uA) 3500 Switching frequency (Min) (kHz) 200 Switching frequency (Max) (kHz) 1200 Features Enable, Frequency Synchronization, Power Good, Pre-Bias Start-Up, Remote Sense, Synchronous Rectification, Tracking Operating temperature range (C) -40 to 125 Regulated outputs (#) 1 Number of phases 1 Rating Catalog
WQFN (RTW) 24 16 mm² 4 x 4
  • Up to 97% Efficiency and 93% Duty Cycle
  • Wide Input Voltage Range of 3 V to 20 V
  • Switching Frequency From 200 kHz to 1.2 MHz
  • Inductor-DCR-Based Overcurrent Protection With
    Thermal Compensation
  • 0.6-V Reference With 1% Feedback Accuracy
  • 30-ns Min On-Time for Low VOUT
  • Integrated High-Current MOSFET Drivers
    • Adaptive Deadtime Control
  • Ultrafast Line and Load Transient Response
    • High GBW Error Amplifier
    • PWM Line Feedforward
  • Integrated VDD Bias Supply LDO Subregulator
  • Programmable System-Level OTP
  • Precision Enable With Hysteresis
  • Frequency Synchronization
  • Monotonic Prebiased Start-up
  • Programmable Soft-Start With Tracking
  • Output Remote Sense
  • Open-Drain Power Good Indicator
  • 4-mm x 4-mm WQFN-24 PowerPAD™ Package
  • Up to 97% Efficiency and 93% Duty Cycle
  • Wide Input Voltage Range of 3 V to 20 V
  • Switching Frequency From 200 kHz to 1.2 MHz
  • Inductor-DCR-Based Overcurrent Protection With
    Thermal Compensation
  • 0.6-V Reference With 1% Feedback Accuracy
  • 30-ns Min On-Time for Low VOUT
  • Integrated High-Current MOSFET Drivers
    • Adaptive Deadtime Control
  • Ultrafast Line and Load Transient Response
    • High GBW Error Amplifier
    • PWM Line Feedforward
  • Integrated VDD Bias Supply LDO Subregulator
  • Programmable System-Level OTP
  • Precision Enable With Hysteresis
  • Frequency Synchronization
  • Monotonic Prebiased Start-up
  • Programmable Soft-Start With Tracking
  • Output Remote Sense
  • Open-Drain Power Good Indicator
  • 4-mm x 4-mm WQFN-24 PowerPAD™ Package

The LM27403 is a feature-rich, easy-to-use, synchronous buck controller offering exceptional levels of integration and performance for superior efficiency in high power density, point-of-load (POL) DC-DC regulator solutions. The resistor-programmable switching frequency from 200 kHz to 1.2 MHz and integrated, high-current MOSFET gate drivers with adaptive deadtime offer flexibility to optimize solution size and maximize conversion efficiency.

High precision and low output voltage are easily obtained with a 0.6-V, 1% accurate voltage reference together with a 30-ns high-side MOSFET minimum controllable on-time. Using lossless inductor dc resistance (DCR) current sensing and an inexpensive 2N3904 BJT to sense temperature remotely at the inductor, the LM27403 supports accurate and thermally compensated overcurrent protection (OCP).

The LM27403 has a conventional voltage-mode control loop with high gain-bandwidth error amplifier and PWM input voltage feedforward to simplify compensation design and enable excellent transient response throughout the full line voltage and load current ranges. Forced-PWM (FPWM) operation eliminates frequency variation to minimize EMI in sensitive applications. An open-drain Power Good circuit provides power-rail sequencing and fault reporting. Other features include programmable system-level thermal shutdown with automatic recovery, output voltage remote sense, configurable soft-start, monotonic start-up into prebiased loads, an integrated bias supply low-dropout (LDO) regulator, external power supply tracking, precision enable with customizable hysteresis for programmable line undervoltage lockout (UVLO), and synchronization capability for beat frequency sensitive and multiregulator applications. The LM27403 is offered in a 4-mm x 4-mm thermally enhanced WQFN-24 package with 0.5-mm pitch.

The LM27403 is a feature-rich, easy-to-use, synchronous buck controller offering exceptional levels of integration and performance for superior efficiency in high power density, point-of-load (POL) DC-DC regulator solutions. The resistor-programmable switching frequency from 200 kHz to 1.2 MHz and integrated, high-current MOSFET gate drivers with adaptive deadtime offer flexibility to optimize solution size and maximize conversion efficiency.

High precision and low output voltage are easily obtained with a 0.6-V, 1% accurate voltage reference together with a 30-ns high-side MOSFET minimum controllable on-time. Using lossless inductor dc resistance (DCR) current sensing and an inexpensive 2N3904 BJT to sense temperature remotely at the inductor, the LM27403 supports accurate and thermally compensated overcurrent protection (OCP).

The LM27403 has a conventional voltage-mode control loop with high gain-bandwidth error amplifier and PWM input voltage feedforward to simplify compensation design and enable excellent transient response throughout the full line voltage and load current ranges. Forced-PWM (FPWM) operation eliminates frequency variation to minimize EMI in sensitive applications. An open-drain Power Good circuit provides power-rail sequencing and fault reporting. Other features include programmable system-level thermal shutdown with automatic recovery, output voltage remote sense, configurable soft-start, monotonic start-up into prebiased loads, an integrated bias supply low-dropout (LDO) regulator, external power supply tracking, precision enable with customizable hysteresis for programmable line undervoltage lockout (UVLO), and synchronization capability for beat frequency sensitive and multiregulator applications. The LM27403 is offered in a 4-mm x 4-mm thermally enhanced WQFN-24 package with 0.5-mm pitch.

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Design & development

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

Evaluation board

LM27403EVM — LM27403 High Efficiency 12V to 1.2V/25A Buck Eval Kit With Temp Compensated DCR Current Sensing

The LM27403 EVM is a 300-kHz, high efficiency, synchronous buck converter with voltage-mode control and inductor DCR current sensing for overcurrent protection. An inexpensive 2N3904 BJT is used to sense temperature at the inductor. This enables correction for the inductor DCR’s variation over (...)
In stock
Limit: 5
Evaluation board

LM27403EVM-POL600 — Evaluation Module - LM27403 600kHz High Power Density POL

LM27403EVM-POL600 is a 600-kHz synchronous buck dc-dc regulator showcasing high power density and high efficiency. A 20 mm x 15 mm module on a single-side PCB uses a power block MOSFET from TI. Accurate overcurrent protection is available by leveraging the inductor’s sub-mΩ DCR and (...)

In stock
Limit: 5
Simulation model

LM27403 PSpice Transient Model (Rev. B)

SNVM503B.ZIP (150 KB) - PSpice Model
Simulation model

LM27403 Unencrypted PSpice Transient Model

SNVM842.ZIP (5 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 (...)
Calculation tool

LM27403DESIGN-CALC — LM27403 PWM Regulator Design Tool Calculator

Welcome to the LM27403 Quick-Start Design Tool. This stand-alone tool facilitates and assists the power supply engineer with design of a DC/DC buck regulator based on the LM27403 voltage-mode PWM controller. As such, the user can expeditiously arrive at an optimized design to meet the application (...)
Reference designs

PMP8000 — High-Efficiency Small Form factor 150W Sync Buck Reference Design

PMP8000 is a single-phase synchronous switching regulator rated for 5V, 30A output from an input voltage of 12V. This design uses the LM27403 synchronous buck controller and two CSD87350Q5D power block MOSFETs to provide maximum efficiency when combined with a 250nH ferrite output inductor. This (...)
Reference designs

PMP10740 — High-Efficiency Small Form Factor 35W Sync Buck Reference Design

PMP10740 is a single-phase synchronous switching regulator rated for 1V, 35A output from an input voltage of 5V. This design uses the LM27403 synchronous buck controller and two CSD87350Q5D power block MOSFETs to provide maximum efficiency when combined with a 250nH ferrite output inductor. This (...)
Reference designs

PMP10691 — High-Efficiency Small Form Factor 112W Sync Buck Reference Design

PMP10691 is a single-phase synchronous switching regulator rated for 3.3V, 35A output from an input voltage of 12V. This design uses the LM27403 synchronous buck controller and two CSD87350Q5D power block MOSFETs to provide maximum efficiency when combined with a 250nH ferrite output inductor. This (...)
Reference designs

PMP9254 — LM27403 Step-Down Regulator Delivering 1.8V at 30A Reference Design

PMP9254 is a single-phase synchronous switching regulator accepting an input voltage range of 4.5Vin to 20Vin and providing an output voltage of 1.8Vout capable of supplying 30A of current. This design features an especially high power density (1.8Vout @ 30A in a 20mm x 15mm board) with (...)
Reference designs

PMP7996 — LM27403 Step-Down Regulator Delivering 0.9V at 30A Reference Design

PMP7996 is a single-phase switching regulator accepting an input voltage range of 10.8Vin to 13.2Vin and providing an output voltage of 0.9Vout capable of supplying 30A of current. This design uses the LM27403 synchronous buck controller with lossless inductor DCR current sensing capability, which (...)
Reference designs

PMP7935 — High Power Density Voltage Regulator Module for CPU Core Power in Enterprise Switching

PMP7935 is a single-phase synchronous switching regulator module rated for 0.9V, 45A output from an input voltage of 12V. It is used for CPU core power in an enterprise network switching application. The small 1.1"x0.65" module delivers 90% peak efficiency and is smaller and less costly than (...)
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