Overview
Features and Benefits
- Wide VIN Range: 4V to 36V
- Sense Resistor Optional
- True Current Mode Control
- 2% to 90% Duty Cycle at 200kHz
- tON(MIN) ≤ 100ns
- Stable with Ceramic COUT
- Dual N-Channel MOSFET Synchronous Drive
- Power Good Output Voltage Monitor
- ±1% 0.6V Reference
- Adjustable Current Limit
- Adjustable Switching Frequency
- Programmable Soft-Start
- Output Overvoltage Protection
- Optional Short-Circuit Shutdown Timer
- Micropower Shutdown: IQ ≤ 30µA
- Available in a 1mm 20-Lead TSSOP Package
Product Details
The LTC3778 is a synchronous step-down switching regulator controller for computer memory, automobile and other DC/DC power supplies. The controller uses a valley current control architecture to deliver very low duty cycles without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in VIN and VOUT.
Discontinuous mode operation provides high efficiency operation at light loads. A forced continuous control pin reduces noise and RF interference, and can assist secondary winding regulation when the main output is lightly loaded. SENSE+ and SENSE– pins provide true Kelvin sensing across the optional sense resistor or the sychronous MOSFET.
Fault protection is provided by internal foldback current limiting, an output overvoltage comparator, optional short-circuit shutdown timer and input undervoltage lockout. Soft-start capability for supply sequencing is accomplished using an external timing capacitor. The regulator current limit level is user programmable. Wide supply range allows operation from 4V to 36V at the input and from 0.6V up to (0.9)VIN at the output.
Applications
- Notebook and Palmtop Computers, PDAs
- Battery Chargers
- Distributed Power Systems
- DDR Memory Power Supply
- Automobile DC Power Supply
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 (3)
Documentation
Reliability Data (1)
Evaluation Kit Manuals (1)
Tools & Simulations
LTspice
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.

Models for the following parts are available in LTspice:
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.
Support & Discussions
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.