Features and Benefits
- Output Stages Operate Antiphase Reducing Input Capacitance Requirements and Power Supply Induced Noise
- Dual Input Supply Capability for Load Sharing
- 5-Bit Mobile VID Code: VOUT = 0.925V to 2V
- Current Mode Control Ensures Current Sharing
- True Remote Sensing Differential Amplifier
- Power Good Output Indicator
- OPTI-LOOP™ Compensation Minimizes COUT
- Three Operational Modes: PWM, Burst and Cycle Skip
- 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
- Active Voltage Positioning Capable
- Available in 36-Lead Narrow SSOP Package
The LTC1709-7 is a 2-phase, VID programmable, synchronous step-down switching regulator controller that drives 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 up 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 operating mode select pin (FCB) can be used to regulate a secondary winding or select among three modes including Burst Mode™ operation for highest efficiency. An internal differential amplifier provides true remote sensing of the regulated supply’s positive and negative output terminals as required in 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.
|LTC1709||1.3V to 3.5V||VRM8.4|
|LTC1709-7||0.925V to 2V||Mobile|
|LTC1709-8||1.3V to 3.5V||VRM8.4|
|LTC1709-85||1.05V to 1.825V||VRM8.5|
|LTC1709-9||1.1V to 1.85V||VRM9.0|
- Mobile/Desktop Computers
- Internet Servers
- Large Memory Arrays
- DC Power Distribution Systems
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Tools & Simulations
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.
Models for the following parts are available in LTspice:
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.
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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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.