Power Management Switching Regulator Digitally Programmable Regulators

LTC2974 - 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement

LTC3880 - Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management

LTC1709-8 - 2-Phase, 5-Bit VID, Current Mode, High Efficiency, Synchronous Step-Down Switching Regulators

Features

  • Single Controller Operates Two Output Stages Antiphase Reducing Required Input Capacitance and Power Supply Induced Noise
  • Two 5-Bit Desktop VID Codes: LTC1709-8 For VRM8.4 (VOUT from 1.3V to 3.5V) LTC1709-9 For VRM9.0 (VOUT from 1.1V to 1.85V)
  • Current Mode Control Ensures Best Current Sharing
  • True Remote Sensing Differential Amplifier
  • Power Good Output Indicator
  • OPTI-LOOP™ Compensation Minimizes COUT
  • Programmable Fixed Frequency: 150kHz to 300kHz
  • ±1% Output Voltage Accuracy
  • Wide VIN Range: 4V to 36V Operation
  • Adjustable Soft-Start Current Ramping
  • Internal Current Foldback and Short-Circuit Shutdown
  • Overvoltage Soft Latch Eliminates Nuisance Trips
  • Low Shutdown Current: 20µA
  • Available in 36-Lead Narrow SSOP Package

Typical Application

LTC1709-8 Typical Application

Description

The LTC1709-8/LTC1709-9 are 2-phase, VID programmable, synchronous step-down switching regulator controllers that drive two all N-channel external power MOSFET stages in a fixed frequency architecture. The 2-phase controller drives its two output stages out of phase at frequencies from 150kHz to 300kHz to minimize the RMS ripple currents in both input and output capacitors. The 2-phase technique effectively multiplies the fundamental frequency by two, improving transient response while operating each channel at an optimum frequency for efficiency. Thermal design is also simplified.

An internal differential amplifier provides true remote sensing of the regulated supply’s positive and negative output terminals as required for high current applications.

The RUN/SS pin provides soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when the overcurrent latchoff is disabled. OPTI-LOOP compensation allows the transient response to be optimized for a wide range of output capacitors and ESR values. The LTC1709-8/LTC1709-9 implement two different VID tables compliant with VRM8.4 and VRM9.0 respectively.

  Vout Range
 VRM
LTC1709 1.3V to 3.5V VRM8.4
LTC1709-7 0.925V to 2V Mobile
LTC1709-8 1.3V to 3.5V VRM8.4
LTC1709-8.5 1.05V to 1.825V VRM8.5
LTC1709-9 1.1V to 1.85V VRM9.0

Packaging

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
Drawing		 RoHS
LTC1709EG-8#PBF SSOP-36 G E 05-08-1640 (G36) Yes
LTC1709EG-8#TRPBF SSOP-36 G E 05-08-1640 (G36) Yes


LTC1709-8 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
(1-99)		 Price
(1k)*		 RoHS
LTC1709EG-8#PBF SSOP-36 E $5.60 $4.75 Yes
LTC1709EG-8#TRPBF SSOP-36 E $4.85 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
DC292A LTC1709EG-8 | High Current Microprocessor Supply, 12Vin, 1.6Vout @ 52A, (10mm X 20mm Thru-hole Sanyo Caps) Contact Factory
DC292B-B LTC1709EG-8 | High Current VRM 8.4 CPU Power Supply, 12Vin, 1.6Vout @ 45A, (mostly Surface Mount Caps) Contact Factory
Buy Now
Click here to view our complete list of demo boards

Applications

  • Workstations
  • Internet Servers
  • Large Memory Arrays
  • DC Power Distribution Systems

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

Models for the following parts are available in LTspice:
LTC1709
LTC1709-7
LTC1709-8
LTC1709-85
LTC1709-9

Technical Support