Overview
Features and Benefits
- DDR Power Supply, Termination and Reference
- High Efficiency: Up to 94%
- Dual Outputs with ±3A Output Current Capability
- 2.25V to 5.5V Input Voltage Range
- ±1% Output Voltage Accuracy
- VTT Output Voltage Down to 0.5V
- Shutdown Current ≤1μA
- VTTR = VDDQIN/2, VFB2 = VTTR
- Adjustable Switching Frequency Up to 4MHz
- Internal or External Compensation
- Selectable 0°/90°/180° Phase Shift Between Channels
- Internal or External Soft-Start for VDDQ, Internal Soft-Start for VTT
- Power Good Status Outputs
- Low Profile 4mm × 4mm QFN-24 and TSSOP-24 Packages
Product Details
The LTC3618 is a dual synchronous step-down regulator using a current mode, constant-frequency architecture. It provides a complete DDR solution with an input voltage range from 2.25V to 5.5V.
The output of the first step-down regulator offers a high accuracy VDDQ supply. A buffered reference generates VTTR at 50% of VDDQIN and drives loads up to ±10mA. The second regulator generates the DDR termination voltage (VTT) equal to VTTR. Both regulators are capable of delivering ±3A of load current at 1MHz switching frequency.
The operating frequency is externally programmable up to 4MHz, allowing the use of small surface mount inductors. 0°, 90°, or 180° of phase shift between the two channels can be selected to minimize input current ripple. For switching noise-sensitive applications, the LTC3618 can be synchronized to an external clock up to 4MHz.
The LTC3618 is offered in leadless 24-pin 4mm × 4mm QFN and thermally enhanced 24-pin TSSOP packages.
Applications
- DDR Memory
- Supports DDR, DDR2, and DDR3 Standards
- Tracking Supplies
Product Lifecycle
Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
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.
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:
Reference Designs (1)
Reference Materials
Press Releases (1)
Design Resources
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Support & Discussions
LTC3618 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.