LB11860T

PRODUCT INFORMATION Vol.171 Direct PWM Variable Speed Fan Motor Driver IC Developed Easily implements variable speed control of PC cooling fan and cooling water pump motors, and can also be used in fuel and air pumps in fuel cells LB11860T, LB11861/M/H Overview The personal computer market is expected to grow by over 110% relative to the previous year in both quarters of the second half of 2003, and continued growth is forecast for 2004. While desktop PCs are, of course, showing brisk sales, it is the notebook personal computer that is the driving force behind this growth. While trends such as the increasingly widespread availability of broadband networks and the increasing use of multimedia are seen as forming the background for this growth, the increasingly high level of personal computer use is naturally driving demand for higher functionality. The radically higher operating speeds in CPUs and video cards is resulting in increasing amounts of heat generated by this high-speed operation. At the same time, there are also strong demands for miniaturization and quieter operation. Thus conventional air cooling methods are now reaching the limits of their applicability. Currently, both notebook and desktop personal computers often use three or more cooling fans to cool the interior of the computer. Although increased cooling capacity in each fan is desired, the market desires fan motor drivers that implement the following responses to the increases in noise and power associated...