LTC1909-8 Wide Operating Range, No Rsense Step-Down DC/DC Controller with SMBus Programming

The LTC®1909-8 is a synchronous step-down switching regulator controller with a digitally programmable output voltage. The output voltage is selected from one of two 5-bit settings programmed into internal registers via a 2-wire SMBus/I²C interface. The interface features safeguards against invalid output voltages and allows the microprocessor to turn the regulator on and off. Valley current control delivers very low duty cycles without requiring a sense resistor. Operating frequency is selected by an external resistor and is compensated for variations in VIN and VOUT.

Discontinuous mode operation provides high efficiency operation at light loads. A forced continuous control pin reduces noise and RF interference and can assist secondary winding regulation by disabling discontinuous mode operation when the main output is lightly loaded.

Fault protection is provided by internal foldback current limiting, an output overvoltage comparator and optional short-circuit shutdown timer.

The LTC1909-8 is available in the 28-lead SSOP package

产品特点 Features
  • SMBus/I²C™ Programmable Output Voltage: 1.3V to 3.5V
  • No Sense Resistor Required
  • 2% to 90% Duty Cycle at 200kHz
  • tON(MIN) </= 100ns
  • True Current Mode Control
  • Stable with Ceramic COUT
  • Power Good Output Voltage Monitor and 50µs Timer
  • Wide VIN Range: 4V to 36V (Abs Max)
  • Precision Resistor Divider and Reference Provide ±1.35% Output Voltage Accuracy Over Temperature
  • Adjustable Switching Frequency and Current Limit
  • Forced Continuous Control Pin
  • Programmable Soft-Start
  • Output Overvoltage Protection
  • Optional Short-Circuit Shutdown Timer
  • Available in a 28-Lead SSOP Package
应用
  • Power Supplies for DSPs, ASICs, FPGAs and CPUs
  • Voltage Margining
典型应用图
LTC1909-8 典型应用
参数
LTC1909-8 参数
LTC1909-8 订购信息和价格参考Package Variations and Pricing
器件型号 封装 引脚 温度 价格 (以 1 ~ 99 片为批量) 价格 (以 1000 片为批量) *
LTC1909-8EGN SSOP 16 E $4.26  $3.60 
LTC1909-8EGN#PBF SSOP 16 E $4.26  $3.60 
LTC1909-8EGN#TR SSOP 16 E $3.66 
LTC1909-8EGN#TRPBF SSOP 16 E $3.66 
LTC1909-8 数据手册及相关资料下载
  1. 数据手册(英文) : LTC1909-8 - Wide Operating Range, No Rsense Step-Down DC/DC Controller with SMBus Programming.PDF
  2. 设计要点 (英文) : Design Solutions 10 - Active Voltage Positioning Reduces Output Capacitors.PDF
  3. 可靠性数据 : R384 Reliability Data .PDF