Alternative Parts
Overview
Features and Benefits
- No Sense Resistor Required
- True Current Mode Control
- Optimized for High Step-Down Ratios
- tON(MIN) <=100ns
- Extremely Fast Transient Response
- Stable with Ceramic COUT
- Dual N-Channel MOSFET Synchronous Drive
- Power Good Output Voltage Monitor (LTC1778)
- Adjustable On-Time (LTC1778-1)
- Wide VIN Range: 4V to 36V
- ±1% 0.8V Voltage 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 16-Pin Narrow SSOP Package
Product Details
The LTC1778 is a synchronous stepdown switching regulator controller optimized for CPU power. The controller uses a valley current control architecture to deliver very low duty cycles with excellent transient response without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in VIN.
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 by disabling discontinuous operation when the main output is lightly loaded.
Fault protection is provided by internal foldback current limiting, an output overvoltage comparator and optional short-circuit shutdown timer. 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 0.8V up to (0.9)VIN at the output.
Applications
- Notebook and Palmtop Computers, PDAs
- Distributed Power Systems
Product Categories
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)
Documentation & Resources
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R384 Reliability Data3/26/2018
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DC378A - Demo Manual8/3/2012
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DC385A - Demo Manual9/24/2009
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Design Note 279: Microprocessor Core Supply Voltage Set by I2C Bus without VID Lines8/21/2021
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Design Solutions 43 - High Performance Switch Mode Power Solutions for Altera Low Voltage FPGAs8/21/2007
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Design Note 258: High Efficiency I/O Power Generation for Mobile Pentium III Microprocessors5/1/2001
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Compact No RSENSE Controllers Feature Fast Transient Response and Regulate to Low VOUT from Wide Ranging VIN6/1/2009 LT Journal
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Low Voltage, High Current DC/DC Power Supply with Load Sharing and Redundancy8/1/2002 LT Journal
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SMBus Controls CPU Voltage Regulators without VID Pins9/1/2001 LT Journal
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New No RSENSE Controllers Deliver Very Low Output Voltages2/1/2001 LT Journal
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.
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:
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 |
---|---|---|---|---|
LTC1778EGN#PBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
LTC1778EGN#TRPBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
LTC1778EGN-1#PBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
LTC1778EGN-1#TRPBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
LTC1778IGN#PBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
LTC1778IGN#TRPBF | Material Declaration | Reliability Data | 16-Lead SSOP (Narrow 0.15 Inch) | |
Wafer Fabrication Data | R384 Reliability Data |
PCN-PDN Information
Select a model from the dropdown below to subscribe to PCN/PDN notifications and view past notifications as well.
Support & Discussions
LTC1778 Discussions
Sample & Buy
Ordering FAQs
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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
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Sampling
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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.