1. Products
  2. Power Management
  3. Switching Regulators
  4. Step-Down (Buck) Regulators
  5. External Power Switch Buck Controllers
  6. LTC3878


Features and Benefits

  • Wide VIN Range: 4V to 38V
  • ±1% 0.8V 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 Into Pre-Biased Output
  • Optimized for High Step-Down Ratios
  • Pin Compatible with the LTC1778 (No EXTVCC Pin)
  • Power Good Output Voltage Monitor
  • Dual N-Channel MOSFET Synchronous Drive
  • Adjustable Switching Frequency
  • Programmable Current Limit with Foldback
  • Output Overvoltage Protection
  • Small 16-Pin Narrow SSOP Package

Product Details

The LTC3878 is a synchronous step-down switching DC/DC 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. The LTC3878 is pin compatible with the LTC1778 in applications that do not use EXTVCC while offering better efficiency. Consult with the factory to verify compatibility.

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. Soft-start capability for supply sequencing is accomplished through an external timing capacitor. The current limit is user programmable.

The LTC3878 allows operation from 4V to 38V at the input and from 0.8V to 90% VIN at the output. The LTC3878 is available in a small 16-pin narrow SSOP package.


  • Distributed Power Systems
  • Embedded Computing
  • Communications Infrastructure

Product Lifecycle icon-recommended 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)

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 Recommendations

LTC3878 Companion Parts

Recommended Related Parts

Design Resources

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.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
LTC3878EGN#PBF Material Declaration Reliability Data 16-Lead SSOP (Narrow 0.15 Inch)
LTC3878EGN#TRPBF Material Declaration Reliability Data 16-Lead SSOP (Narrow 0.15 Inch)
LTC3878IGN#PBF Material Declaration Reliability Data 16-Lead SSOP (Narrow 0.15 Inch)
LTC3878IGN#TRPBF Material Declaration Reliability Data 16-Lead SSOP (Narrow 0.15 Inch)
Wafer Fabrication Data R526 Reliability Data

PCN-PDN Information

Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.

Sample & Buy

Ordering FAQs

See our Ordering FAQs for answers to questions about online orders, payment options and more.


Buy Now Pricing

(**) Displayed Buy Now Price and Price Range is based on small quantity orders.


List Pricing

(*)The 1Ku 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. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.


Lead Times

Please see the latest communication from our CCO regarding lead times.



Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.

Price Table Help


Evaluation Boards

Pricing displayed is based on 1-piece.

Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.