LTC1695 - SMBus/I²C Fan Speed Controller in SOT-23

The LTC®1695 fan speed controller provides all the functions necessary for a power management microprocessor to regulate the speed of a 5V brushless DC fan via a 2-wire SMBus/I²C interface. Fan speed is controlled according to the system’s required temperature profile and permits lower fan power consumption, longer battery run time and lower acoustical generated noise versus systems that only provide simple on-off control for the fan. The LTC1695 incorporates a 180mA low dropout linear regulator, a 2-wire SMBus/I²C interface and a 6-bit DAC. Fan speed is controlled by varying the fan’s terminal voltage through the output voltage of the LTC1695’s linear regulator. The LTC1695’s output voltage is programmed by sending a 6-bit digital code to the LTC1695 DAC via the SMBus. To eliminate fan start-up problems at lower fan voltages, users can enable the LTC1695’s boost start feature that provides the DAC’s full-scale output voltage for 250ms before decreasing to the programmed output voltage. The LTC1695 includes output current limiting and thermal shutdown as well as status monitors that can be read back by the microprocessor during fault conditions. The LTC1695 is available in a 5-lead SOT-23 package.

  • Complete SMBus/I²C™ Brushless DC Fan SpeedControl System in a 5-Pin SOT-23 package
  • 0.75Ohms PMOS Linear Regulator with 180mAOutput Current Rating
  • 0V to 4.922V Output Voltage Range Controlled by a6-Bit DAC
  • Simple 2-Wire SMBus/I²C Interface
  • 250ms Internal Timer Ensures Fan Start-Up
  • Current Limit and Thermal Shutdown
  • Fault Status Indication via SMBus Host Readback
LTC1695 Typical Application
LTC1695 Typical Application
  • Notebook Computers
  • Spot Cooling
  • Portable Instruments
  • Battery-Powered Systems
  • DC Motor Control
  • White LED Power Supplies
  • Programmable Low Dropout Regulator
LTC1695 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) *
DC285ALTC1695CS5 | SMBus Fan Speed Controller (req. DC1223)$75.00
Companion Boards
DC1223A-BUSB to SM-Bus/SPI Interface with Monitor$400.00
LT Journal
CAD 符号
LTC1695 - SMBus/I²C Fan SpeedController in SOT-23
DN238 - SOT-23 SMBus Fan Speed Controller Extends Battery Life and Reduces Noise
R421 Reliability Data
May 2000 SOT-23 SMBus Fan Speed Controller Extends Battery Life and Reduces Noise
LTC1695 Footprints and Symbols