LTC1709 - 2-Phase, 5-Bit Adjustable,High Efficiency, Synchronous Step-Down Switching Regulator
Features
- Two Ouput Stages Operate Antiphase Reducing
Input Capacitance and Power Supply Noise - 5-Bit VID Control (VRM 8.4 Compliant)
VOUT: 1.3V to 3.5V in 50mV/100mV Steps - Current Mode Control Ensures Current Sharing
- True Remote Sensing Differential Amplifier
- OPTI-LOOP™ Compensation Minimizes COUT
- Programmable Fixed Frequency: 150kHz to
300kHz—Effective 300kHz to 600kHz Switching
Frequency - ±1% Output Voltage Accuracy
- Wide VIN Range: 4V to 36V Operation
- Adjustable Soft-Start Current Ramping
- Internal Current Foldback
- Short-Circuit Shutdown Timer with Defeat Option
- Overvoltage Soft-Latch Eliminates Nuisance Trips
- Low Shutdown Current: 20µA
- Small 36-Lead Narrow (0.209") SSOP Package
Typical Application
Description
The LTC1709 is a 2-phase, VID programmable, synchronous step-down switching regulator controller that drives 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 a 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 in high current applications. The RUN/SS pin provides soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipaton during short-circuit conditions when overcurrent latchoff is disabled. OPTI-LOOP compensation allows the transient response to be optimized for a wide range of output capacitors and ESR values.
| 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 |
| LTC1709-85 | 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#PBF | SSOP-36 | G | E | 05-08-1640 (G36) | Yes |
| LTC1709EG#TRPBF | SSOP-36 | G | E | 05-08-1640 (G36) | Yes |
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#PBF | SSOP-36 | E | $5.60 | $4.75 | Yes | |
| LTC1709EG#TRPBF | SSOP-36 | E | $4.85 | Yes | ||
| Buy Now • Request Samples | ||||||
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.Click here to view our complete list of demo boards
Applications
- Desktop Computers
- Internet/Network Servers
- Large Memory Arrays
- DC Power Distribution Systems
- Battery Chargers
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Product Notifications
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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
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
