Features and Benefits
- Wide VIN Range: 4V to 38V
- ±1% 0.6V Voltage Reference
- Extremely Fast Transient Response
- tON(MIN): 43ns
- No RSENSE™ Valley Current Mode Control
- Stable with Low ESR Ceramic COUT
- Supports Smooth Start-Up in Pre-Biased Output
- Optimized for High Step-Down Ratios
- Adjustable Output Voltage Soft-Start or Tracking
- Power Good Output Voltage Monitor
- Dual N-Channel MOSFET Synchronous Drive
- Adjustable Switching Frequency
- Programmable Current Limit with Foldback
- Output Overvoltage Protection
- 16-Pin MSOP and 3mm × 3mm QFN Packages
The LTC3879 is a synchronous step-down switching regulator controller optimized for high switching frequency and fast transient response. The constant on-time valley current mode architecture allows for a wide input range, including very low duty factor operation. No external sense resistor or slope compensation is required. System flexibility is offered through a user-programmable soft-start pin and independent RUN pin. The voltage ramping soft-start function can be programmed with a capacitor or made to track an external reference source.
Operating frequency is set by an external resistor and compensated for variations in VIN to offer excellent line stability. Discontinuous mode operation provides high efficiency during light load conditions. A forced continuous control pin allows the user to reduce noise and RF interference. Safety features include output overvoltage protection and programmable current limit with foldback. The current limit is user programmable.
The LTC3879 allows operation from 4V to 38V at the input and from 0.6V to 90% VIN at the output. The LTC3879 is available in a small 16-pin thermally enhanced MSOP or 3mm × 3mm QFN packages.
- Distributed Power Systems
- Embedded Computing
- Communications Infrastructure
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 (2)
Demonstration circuit 1345 is a wide input voltage range, no Rsense step-down dc/dc converter featuring the LTC3879EMSE. Its output voltage is 1.2V with a load rating of 12A and the input voltage range is 4.5V to 34V.
Demonstration circuit 1289 is a no RSENSE synchronous step-down DC/DC converter featuring the LTC3879EUD. Its output supplies 1.2V @ 15A and its input voltage range is from 4.5V to 14V.
The LTC3879 allows operation from 4V to 38V at the input and has an output voltage range of 0.6V to 0.9VIN.
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:
Product Selector Card (1)
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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.