Dual I2C Fan Speed Controller Directs DC/DC Converters

The LTC1840 is a dual fan speed controller with a 2-wire interface for network servers, desktop PCs or other high efficiency applications where a separate dc/dc converter drives each fan. The LTC1840 includes two 8-bit DACs with full-scale output of 100 µA to sink current from the feedback nodes of the dc/dc converters controlling the voltage to each fan. The controller reads the tachometer outputs from each fan to provide feedback to the processor over an I2C or SMBus compatible 2-wire bus. Available in a 16-pin SSOP package, the controller is specified for both the commercial and industrial temperature ranges. Pricing for the LTC1840 fan speed controller starts at $2.75 each/1,000. LINEAR TECHNOLOGY CORP., Milpitas, CA. (408) 432-1900.