industry news
Subscribe Now

High Efficiency ±6A Switching Regulator for DDR Termination Complies with DDR/DDR2/DDR3 Standards

MILPITAS, CA – July 7, 2011 – Linear Technology Corporation introduces the LTC3617, a high efficiency, monolithic synchronous step-down switching regulator, capable of generating a bus termination voltage for DDR/DDR2/DDR3 and future standard memory applications requiring sourcing and sinking of current. An internal resistor divider sets the VTT DDR termination supply and VTTR reference voltages equal to half the voltage applied to the input, with output current capability of ±6A (sinking/sourcing) at VTT and ±10mA at VTTR. The outputs are capable of operation down to 0.5V. The device operates from an input voltage range of 2.25V to 5.5V and allows switching frequencies as high as 4MHz, allowing for very small externals. This creates a small, compact solution footprint that is preferred for laptop computers and graphics card applications, which need ±6A or less for DDR termination. The internal synchronous top and bottom power switches have an RDS(ON) of only 35mOhm and 25mOhm respectively, enabling the LTC3617 to attain efficiencies as high as 93%, eliminating the need for an external catch diode while minimizing external component count and board space.

The LTC3617 utilizes a constant frequency, current-mode architecture. The switching frequency can be set between 300kHz and 4MHz by a single external resistor. This high frequency capability enables use of smaller capacitor values, while maintaining low output voltage ripple. For noise-sensitive switching applications, the LTC3617 can be synchronized to an external clock up to 4MHz. Forced continuous mode operation helps reduce noise and RF interference. Optional external compensation allows optimization of transient response over a wide range of loads and output capacitors. The device uses an input overvoltage lockout circuit to protect the input supply from back-boosting.

For optimal thermal performance, the LTC3617 is offered in a thermally enhanced 24-pin 3mm x 5mm QFN package. The device is guaranteed for operation from -40°C to 125°C. 1,000-piece pricing starts at $3.80 for the E grade and $4.20 for the I grade. For more information, visit www.linear.com/product/LTC3617.

Summary of Features: LTC3617

  • ±6A Output Current for VTTTermination Supply
  • 2.25V to 5.5V Input Voltage Range
  • ±10mV Output Voltage Accuracy
  • Optimized for Low Output Voltages Down to 0.5V
  • High Efficiency Synchronous Operation
  • Integrated Buffer for VTTR = VDDQIN • 0.5, ±10mA Output, Termination Reference
  • Shutdown Current: <1µA
  • Adjustable Switching Frequency: Up to 4MHz
  • Optional Internal Compensation
  • Internal Soft-Start
  • Power Good Status Output
  • Input Overvoltage Protected
  • Thermally Enhanced 24-Pin 3mm x 5mm QFN Package

About Linear Technology

Linear Technology Corporation, a member of the S&P 500, has been designing, manufacturing and marketing a broad line of high performance analog integrated circuits for major companies worldwide for three decades. The Company’s products provide an essential bridge between our analog world and the digital electronics in communications, networking, industrial, automotive, computer, medical, instrumentation, consumer, and military and aerospace systems. Linear Technology produces power management, data conversion, signal conditioning, RF and interface ICs, and µModule® subsystems.

LT, LTC, LTM, µModule, and  are registered trademarks of Linear Technology Corp. All other trademarks are the property of their respective owners.

Leave a Reply

featured blogs
Jul 17, 2025
Why do the links in Outlook emails always open in the Microsoft Edge web browser, even if you have another browser set as your default?...

featured paper

AI-based Defect Detection System that is Both High Performance and Highly Accurate Implemented in Low-cost, Low-power FPGAs

Sponsored by Altera

Learn how MAX® 10 FPGAs enable real-time, high-accuracy AI-based defect detection at the industrial edge without a GPU. This white paper explores a production-proven solution that delivers 24× higher accuracy, 488× lower latency, and 20× lower power than traditional approaches, with a compact footprint ideal for embedded vision systems.

Click to read more

featured chalk talk

Automotive MOSFETs
Sponsored by Mouser Electronics and Infineon
In this episode of Chalk Talk, Joseph Sara and Amelia Dalton explore the mega trends motivating MOSFET innovation and the details of Infineon’s cutting-edge MOSFET solutions. They also explore the benefits of Infineon’s OptiMOS 7 platform and how you can take advantage of Infineon MOSFETs for your next design.
Jul 21, 2025
1,553 views