THE MAGAZINE FOR COMPUTER APPLICATIONS
Circuit Cellar Online offers articles illustrating creative solutions
and unique applications through complete projects, practical
tutorials, and useful design techniques.

NEW PRODUCT NEWS—edited by Harv Weiner

Fan Controller with
Remote Temperature Sensor

The MAX1669 fan controller includes a precise digital thermometer that reports the temperature of a remote sensor. The remote sensor is a diode-connected transistor. Remote accuracy is ę3ęC for transistors from multiple manufacturers, with no calibration needed.

The MAX1669 has an independent fan controller with a low-current logic output requiring external power components to interface to a DC fan without a brush. The fan controller has two modes of operation, a low-frequency (20 Hz to 160 Hz) PWM mode intended for driving the fan motor, and a high-impedance DAC output that generates a variable DC control voltage. In PWM mode, the fan frequency can be synchronized to an external clock.

Other features include general-purpose inputs and outputs (GPIOs) for fan detection and a thermostat output. The latter is a fan override signal, in case the host canęt continue communicating.

The MAX 1669 asserts a SMBus alert interrupt if the temperature equals or exceeds the alarm threshold value. The overt output is activated when the temperature equals or exceeds the critical temperature registeręs threshold. The internal ADC has a wide input voltage range and gives over-range readings when too large an input voltage is applied.

The MAX 1669 is available in a 16-pin QSOP package that fits adjacent to the SLOT1 connector. Pricing starts at $3.20 in quantities of 1000. An assembled evaluation kit is available with recommended external components.

Maxim Integrated Products
(408) 737-7600
Fax: (408) 737-7194
www.maxim-ic.com

7-00

Circuit Cellar provides up-to-date information for engineers. Visit www.circuitcellar.com for more information and additional articles.
For subscription information, call (860) 875-2199, subscribe@circuitcellar.com or subscribe online. ęCircuit Cellar, the Magazine for Computer Applications. Posted with permission.