Features and Benefits
- Wide Input Voltage Range: 4V to 30V
- Wide Output Voltage Range: 0.8V to VIN
- Low Shutdown IQ: 20μA
- Out-of-Phase Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
- 0.8V ±1.5% Voltage Reference
- 500kHz Current Mode Fixed Frequency Operation
- Internal Boost Converter Provides Bias Rail for N-Channel MOSFET Gate Drive
- Power Good Voltage Monitor for Each Output
- Programmable Soft-Start
- 24-Lead 4mm × 4mm × 0.75mm Package
The LT3742 is a dual step-down DC/DC switching regulator controller that drives high side N-channel power MOSFETs. A 500kHz ﬁxed frequency current mode architecture provides fast transient response with simple loop compensation components and cycle-by-cycle current limiting. The output stages of the two controllers operate 180° out of phase to reduce the input ripple current, minimizing the noise induced on the input supply, and allowing less input capacitance.
An internal boost regulator generates a bias rail of VIN + 7V to provide gate drive for the N-channel MOSFETs allowing low dropout and 100% duty cycle operation. The LT3742 can be used for applications where both controllers need to operate independently, or where both controllers are used to provide a single higher current output.
The device is available in a thermally enhanced 4mm × 4mm QFN package.
- Satellite and Cable TV Set-Top Boxes
- Distributed Power Regulation
- Automotive Systems
- Super Capacitor Charger
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Demonstration circuit 927 is a dual output step-down converter featuring the LT3742, a two-phase nonsynchronous buck controller. The demo board operates with a 5.5V to 28V input suppy and provides outputs of 5V@4A and 3.3V@4A.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.
Design tools for the following parts are available in LTpowerCAD:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.