The result is a bill of materials that drops by 25%. A typical four-wire fan with overtemperature protection requires 27 components, while a two-wire fan using the new chip requires only 13 components. The TDA21801 can adjust fan speed from 750 to 4,000 rpm, making it a candidate for applications that need low fan speed to reduce noise levels. It generates an overtemperature early warning signal to prevent data loss in case of thermal faults, and also generates a tachometer signal for system monitoring features. The TDA21801 fan speed controller comes in a RoHS-compliant SO-8 package, and costs $0.70 in quantities of 50,000.
Infineon Technologies AG, 1730 North First St., San Jose, CA 95112, (408) 501-6000, www.infineon.com