LTC1709-85 - 2-Phase, 5-Bit VID, Current Mode, High Efficiency, Synchronous Step-Down Switching Regulator

The LTC®1709-85 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 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.

特点
  • Output Stages Operate Antiphase Reducing Input Capacitance Requirements and Power Supply Induced Noise
  • Dual Input Supply Capability for Load Sharing
  • 5-Bit VID Code (VRM 8.5): VOUT = 1.05V to 1.825V
  • True Remote Sensing Differential Amplifier
  • Power Good Output Indicator
  • ±1% Output Voltage Accuracy
  • Active Voltage Positioning Capable
  • Current Mode Control Ensures Current Sharing
  • OPTI-LOOP® Compensation Minimizes COUT
  • Three Operational Modes: PWM, Burst and Cycle Skip
  • Programmable Fixed Frequency: 150kHz to 300kHz
  • 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
  • Available in 36-Lead Narrow SSOP Package
典型应用
LTC1709-85 Typical Application
应用
  • Server/Desktop Computers
  • Internet Servers
  • Large Memory Arrays
  • DC Power Distribution Systems
封装信息
LTC1709-85 Package Drawing
Order Information 订购型号
器件型号封装温度价格 (以 1 ~ 99 片为批量)价格 (以 1000 片为批量) *
LTC1709EG-85#PBFSSOP-36E$5.60$4.75
LTC1709EG-85#TRPBFSSOP-36E$4.85
演示电路板
器件型号描述价格
DC292B-DLTC1709EG-85 | High Current VRM 9.0 CPU Power Supply, 12Vin, 1.6Vout @ 45A, (mostly Surface Mount Caps)联系凌力尔特
数据表
设计要点
可靠性数据
LT Journal
CAD 符号
相关产品
LTC1709-85 - 2-Phase, 5-Bit VID, Current Mode, High Efficiency, Synchronous Step-Down Switching Regulator
Design Solutions 10 - Active Voltage Positioning Reduces Output Capacitors
R384 Reliability Data
Sep 2001 LTC1709-85 High Efficiency Converter with VRM 8.5 Compliant VID Control Minimizes Input and Output Capacitors
LTC1709-85 Footprints and Symbols