With the TC670 predictive fan-failure IC, a single resistor divider is adequate for setting the RPM alarm level. Using this device, predictive fan failure is implemented without the need for software. Since the IC can detect critical fan speeds (RPMs) of two-wire and three-wire fans, there's no need to purchase more expensive three-wire fans.
Fan failure is predicted by sensing fan revolutions and asserting a logic-low alert signal whenever fan speed falls below a user-programmable trip point. Since the TC670 features a pin for clearing the alert signal, it is ideal for interfacing with microprocessors. The TC670's small size and low operating current of 90 A make it ideal for space- and power-critical systems. Targeted applications include telecom and networking equipment, power supplies, instrumentation, data storage equipment, notebooks and servers, and industrial-control applications.
The TC670 is offered in a 6-lead SOT-23 package. In 1000-unit quantities, it costs $0.96 each.
Microchip Technology Inc.
(480) 792-7966; www.microchip.com