LTC3617 - ±6A Monolithic Synchronous Step-Down Regulator for DDR Termination


  • ±6A Output Current
  • 2.25V to 5.5V Input Voltage Range
  • ±10mV Output Voltage Accuracy
  • Optimized for Low Output Voltages Down to 0.5V
  • High Efficiency
  • Integrated Buffer for VTTR = VDDQIN • 0.5
  • 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 × 5mm QFN Package

Typical Application

LTC3617 Typical Application
LTC3617 Typical Application


The LTC3617 is a high efficiency monolithic synchronous buck regulator utilizing a current mode, constant frequency architecture. It operates from an input voltage range of 2.25V to 5.5V and provides a regulated output voltage equal to 0.5 • VDDQIN while sourcing and sinking up to 6A of load current. An internal amplifier provides a VTTR output voltage equal to 0.5 • VDDQIN with an output current capability of ±10mA.

The operating frequency is externally programmable up to 4MHz, allowing the use of small surface mount inductors. For switching-noise-sensitive applications, the LTC3617 can be synchronized to an external clock up to 4MHz.

Forced continuous mode operation in the LTC3617 reduces noise and RF interference. Adjustable external compensation allows the transient response to be optimized over a wide range of loads and output capacitors.

The internal synchronous switch increases efficiency and eliminates the need for an external catch diode, minimizing external component count and board space. The LTC3617 is offered in a leadless 24-pin 3mm × 5mm thermally enhanced QFN package.


CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LTC3617EUDD#PBF 3x5 QFN-24 UDD E 05-08-1833 Yes
LTC3617EUDD#TRPBF 3x5 QFN-24 UDD E 05-08-1833 Yes
LTC3617IUDD#PBF 3x5 QFN-24 UDD I 05-08-1833 Yes
LTC3617IUDD#TRPBF 3x5 QFN-24 UDD I 05-08-1833 Yes

LTC3617 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LTC3617EUDD#PBF 3x5 QFN-24 E $5.43 $3.80 Yes
LTC3617EUDD#TRPBF 3x5 QFN-24 E $3.86 Yes
LTC3617IUDD#PBF 3x5 QFN-24 I $6.00 $4.20 Yes
LTC3617IUDD#TRPBF 3x5 QFN-24 I $4.26 Yes
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* 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 Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1707A LTC3617EUDD Demo Board | VIN=2.25V to 5.5V, Vout1 = 0.5VIN (VTT) @ ±6A, Vout2 = 0.5VIN (VTTR) @ ±10mA $125.00
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  • DDR Termination
  • Supports DDR, DDR2 and DDR3 Standards
  • Tracking Supplies

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