LTC3776
PRODUCTIONDual 2-Phase, No RSENSE™, Synchronous Controller for DDR/QDR Memory Termination
- Part Models
- 4
- 1ku List Price
- Starting From $6.32
Overview
- No Current Sense Resistors Required
- Out-of-Phase Controllers Reduce Required Input Capacitance
- VOUT2 Tracks 1/2 VREF
- Symmetrical Source/Sink Output Current Capability (VOUT2)
- Spread Spectrum Operation (When Enabled)
- Wide VIN Range: 2.75V to 9.8V
- Constant Frequency Current Mode Operation
- 0.6V ±1.5% Voltage Reference (VOUT1)
- 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: IQ = 9µA
- Tiny Low Profile (4mm × 4mm) QFN and Narrow SSOP Packages
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 VREF while providing symmetrical source and sink output current capability.
The No RSENSE 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 VOUT1 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
Documentation
Data Sheet 1
User Guide 1
Press Release 1
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) | ||
| LTC3776EGN#TRPBF | 24-Lead SSOP (Narrow 0.15 Inch) | ||
| LTC3776EUF#PBF | 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP) | ||
| LTC3776EUF#TRPBF | 24-Lead QFN (4mm x 4mm x 0.75mm w/ EP) |
| 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 | |
|
Jan 20, 2022 - 21_0269 Addition of Alternate Assembly Site ASE Taiwan for Select LFCSP Products |
||
| LTC3776EUF#PBF | PRODUCTION | |
| LTC3776EUF#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
Can't find the software or driver you need?
Request a Driver/SoftwareHardware Ecosystem
| Parts | Product Life Cycle | Description |
|---|---|---|
| Power System Management (PSM) & Sequencers 1 | ||
| LTC2974 | RECOMMENDED FOR NEW DESIGNS | 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement |
| Switching Regulators & Controllers 1 | ||
| LTM4632 | RECOMMENDED FOR NEW DESIGNS | Ultrathin, Triple Output, Step-Down μModule Regulator for DDR-QDR4 Memory |
Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LTC3776
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.
Evaluation Kits
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)
Resources
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