LT3740 Step-Down Controller for N-Channel MOSFET Stages

Analog Devices' controllers for portable, handheld industrial, and test and measurement applications

Image of Analog Devices' LT3740 Step-Down Contoller for N-Channel MOSFET Stages Analog Devices' LT3740 is a synchronous step-down switching regulator controller. It drives N-channel power MOSFET stages. It uses valley current mode architecture to achieve very low duty cycles with excellent transient response without requiring a sense resistor.

The LT3740 includes an internal step-up converter to provide a bias 7.8 V higher than the input voltage for the drive. This enables the part to work from an input voltage as low as 2.2 V. The XREF pin is an external reference input that allows the user to override the internal 0.8 V feedback reference with any lower value, allowing full control of the output voltage during operation, output voltage tracking or soft-start. The controller has three current limit levels that can be chosen by connecting the RANGE pin to ground, open, and input respectively.

The LT3740 comes in a small (5 x 3) 16-pin DFN package that has an operating temperature range of -40°C to +85°C. The LT3740 is ideal for portable, handheld industrial, and test and measurement applications.

Typical Application

Image of Analog Devices' LT3740 High Efficiency Step-Down Converter

Image of Analog Devices' LT3740 Efficiency vs Load Current

Features
  • VIN range: 2.2 V to 22 V
  • Internal boost provides 6 V gate drive for VIN down to 2.2 V
  • No sensing resistor required
  • Dual N-channel MOSFET synchronous drive
  • Valley current mode control
  • Optimized for high step-down ratio
  • Power good output voltage monitor
  • 0.8 V reference
  • Three pin-selected current limit levels
  • Constant switching frequency: 300 kHz
  • Programmable soft-start
  • Output voltage tracking
Applications
  • Portable, handhelds
  • Computers
  • Distributed power systems
  • Industrial
  • Test and measurement

LT3740 Step-Down Controllers

ImageManufacturer Part NumberDescriptionOutput ConfigurationTopologyNumber of OutputsAvailable QuantityPriceView Details
IC REG CTRLR BUCK 16-DFNLT3740EDHC#PBFIC REG CTRLR BUCK 16-DFNPositiveBuck1124 - Immediate$5.54View Details
IC REG CTRLR BUCK 16-DFNLT3740EDHC#TRPBFIC REG CTRLR BUCK 16-DFNPositiveBuck10 - Immediate$3.14View Details

Eval Board

ImageManufacturer Part NumberDescriptionOutputs and TypePower - OutputVoltage - OutputAvailable QuantityPriceView Details
EVAL BOARD FOR LT3740DC947AEVAL BOARD FOR LT37401 Non-Isolated Output-1.8V2 - Immediate$148.07View Details
Published: 2018-07-20