LTC3776

PRODUCTION

LTC3776

Dual 2-Phase, No R_SENSE^™, Synchronous Controller for DDR/QDR Memory Termination

PRODUCTION

High Efficiency, 2-Phase, DDR Memory (VDDQ and VTT) Supplies slide

High Efficiency, 2-Phase, DDR Memory (VDDQ and VTT) Supplies

Not the part you were looking for?

Go to Product Selection Table

View All Documentation

Ask a Question

Submit your question below and we will return the best answer from ADI’s knowledge database:

Other places you can find help

Support

Analog Devices Support Portal is a one-stop shop to answer all your ADI questions.

Visit the ADI Support Page

Ask the ADI community for help.

Ask the EngineerZone Community

FAQs

Sales & Ordering FAQs

Part Models 4

1ku List Price Starting From $4.99

Features

No Current Sense Resistors Required
Out-of-Phase Controllers Reduce Required Input Capacitance
V_OUT2 Tracks 1/2 V_REF
Symmetrical Source/Sink Output Current Capability (V_OUT2)
Spread Spectrum Operation (When Enabled)
Wide V_IN Range: 2.75V to 9.8V
Constant Frequency Current Mode Operation
0.6V ±1.5% Voltage Reference (V_OUT1)
Low Dropout Operation: 100% Duty Cycle
True PLL for Frequency Locking or Adjustment
Internal Soft-Start Circuitry
Power Good Output Voltage Monitor
Output Overvoltage Protection
Micropower Shutdown: I_Q = 9µA
Tiny Low Profile (4mm × 4mm) QFN and Narrow SSOP Packages

Additional Details

The LTC3776 is a 2-phase dual output synchronous stepdown switching regulator controller for DDR/QDR memory termination applications. The second controller regulates its output voltage to 1/2 V_REF while providing symmetrical source and sink output current capability.

The No R_SENSE constant frequency current mode architecture eliminates the need for sense resistors and improves efficiency. Power loss and noise due to the ESR of the input capacitance are minimized by operating the two controllers out of phase.

The switching frequency can be programmed up to 750kHz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications, the LTC3776 switching frequency can be externally synchronized from 250kHz to 850kHz, or can be enabled for spread spectrum operation. Forced continuous operation reduces noise and RF interference. Soft-start for V_OUT1 is provided internally and can be extended using an external capacitor.

The LTC3776 is available in the tiny thermally enhanced (4mm × 4mm) QFN package or 24-lead SSOP narrow package.

Protected by U.S. Patents including 5481178, 5929620, 6144194, 6580258, 6304066, 6611131, 6498466, patent pending on Spread Spectrum.

Applications

DDR, DDR II and QDR Memory
SSTL, HSTL Termination Supplies
Servers, RAID Systems
Distributed DC Power Systems

View All Documentation

Ask a Question

Submit your question below and we will return the best answer from ADI’s knowledge database:

Other places you can find help

Support

Analog Devices Support Portal is a one-stop shop to answer all your ADI questions.

Visit the ADI Support Page

Ask the ADI community for help.

Ask the EngineerZone Community

FAQs

Sales & Ordering FAQs

Part Models 4

1ku List Price Starting From $4.99

Technical Documents 3

LTC3776: Dual 2-Phase, No RSENSE Synchronous Controller for DDR/QDR Memory Termination Data Sheet 08/23/2007

R421 Reliability Data 03/23/2018

DC829A - Demo Manual 09/24/2009

Reference Materials 1

Dual, 2-Phase No RSENSE Synchronous Controller for DDR/QDR Memory Termination in a 4mm x 4mm QFN 04/27/2005

Design Resources 4

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 Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LTC3776EGN#PBF	24-Lead SSOP (Narrow 0.15 Inch)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3776EGN#TRPBF	24-Lead SSOP (Narrow 0.15 Inch)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3776EUF#PBF	24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3776EUF#TRPBF	24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys

LTC3776EGN#PBF
Pin/Package Drawing
24-Lead SSOP (Narrow 0.15 Inch)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3776EGN#TRPBF
Pin/Package Drawing
24-Lead SSOP (Narrow 0.15 Inch)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3776EUF#PBF
Pin/Package Drawing
24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3776EUF#TRPBF
Pin/Package Drawing
24-Lead QFN (4mm x 4mm x 0.75mm w/ EP)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

PCN/PDN Information

Filter by Model

Part Models

Product Lifecycle

PCN

Aug 10, 2022

- 22_0177

Laser Top Mark Conversion for QSOP20_24_28 Assembled in ADPG [PNG] and UTL

LTC3776EGN#PBF

PRODUCTION

LTC3776EGN#TRPBF

PRODUCTION

pdf

PCN22_0177_Form

xls

Material_Report

xlsm

Delta Qualification Matrix

Jan 20, 2022

- 21_0269

Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products

LTC3776EUF#PBF

PRODUCTION

LTC3776EUF#TRPBF

PRODUCTION

pdf

PCN21_0269_Form

xls

Material_Report

pdf

Detailed Change Description

pdf

Qualification Results Summary

Filter by Model

Part Models

Product Lifecycle

PCN

Aug 10, 2022

- 22_0177

Laser Top Mark Conversion for QSOP20_24_28 Assembled in ADPG [PNG] and UTL

LTC3776EGN#PBF

PRODUCTION

LTC3776EGN#TRPBF

PRODUCTION

pdf

PCN22_0177_Form

xls

Material_Report

xlsm

Delta Qualification Matrix

Jan 20, 2022

- 21_0269

Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products

LTC3776EUF#PBF

PRODUCTION

LTC3776EUF#TRPBF

PRODUCTION

pdf

PCN21_0269_Form

xls

Material_Report

pdf

Detailed Change Description

pdf

Qualification Results Summary

Companion Parts 2

Parts	Product Life Cycle	Description
DDR/QDR Memory Bus Termination1
LTM4632	RECOMMENDED FOR NEW DESIGNS	Ultrathin, Triple Output, Step-Down μModule Regulator for DDR-QDR4 Memory
Digital Power System Managers1
LTC2974	RECOMMENDED FOR NEW DESIGNS	4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement

DC829A

LTC3776EUF | 2-Phase Dual Step-Down Converter For DDR/QDR Memory Termination, VIN = 2.75V to 8V, VOUT1 = 2.5V (5A @ 5VIN), VOUT2 = 1.25V (±5A @ 5VIN)

DC829A

LTC3776EUF | 2-Phase Dual Step-Down Converter For DDR/QDR Memory Termination, VIN = 2.75V to 8V, VOUT1 = 2.5V (5A @ 5VIN), VOUT2 = 1.25V (±5A @ 5VIN)

Buy Now View Details

Product Detail

DC829A: Demo Board for the LTC3776 - Dual 2-Phase, No R_SENSE Synchronous Controller for DDR/QDR Memory Termination.

Resources

PDF

DC829A - Demo Manual

1.00M

ZIP

DC829A - Design File

966.00K

PDF

DC829A - Schematic

39.00K

DC829A

LTC3776EUF | 2-Phase Dual Step-Down Converter For DDR/QDR Memory Termination, VIN = 2.75V to 8V, VOUT1 = 2.5V (5A @ 5VIN), VOUT2 = 1.25V (±5A @ 5VIN)

LTspice 2

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.