MAX1669 Datasheet | Maxim Integrated

Description 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- typically a low-cost, easily mounted 2N3906 PNP type- replacing conventional thermistors or thermocouples. Remote accuracy is ±3°C for transistors from multiple manufacturers, with no calibration needed. The MAX1669 has an independent fan controller with a lowcurrent logic output requiring external power ponents to interface to a DC brushless fan. The fan controller has two modes of operation: a low-frequency (20Hz to 160Hz) PWM mode intended for driving the fan motor, or 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 key features include general-purpose inputs/outputs (GPIOs) for fan presence detection and a thermostat output intended as a fan override signal in case the host system loses the ability to municate. The internal ADC has a wide input voltage range and gives overrange readings when too large an input voltage is applied. Other error-checking includes temperature out-of-range indication and diode open/short faults. The MAX1669 is available in a space-saving 16-pin QSOP package that allows it to fit adjacent to the SLOT1 connector. PART Features o Measures Remote CPU Temperature o No Calibration Required o 20Hz to 160Hz PWM Output for Fan o PWM Frequency Sync Input (260k Hz) o Flexible Fan Interface: Linear or PWM o SMBus 2-Wire Serial Interface o Programmable Under/Overtemperature Alarms o ALERT Latched Interrupt Output o OVERT Thermostat Output o Two GPIO Pins o Write-Once Configuration Protection o Supports SMBus Alert Response o ±3°C Temperature Accuracy (-40°C to +125°C, remote) o 3µA Standby Supply Current o +3V to +5.5V Supply Range o Small 16-Pin QSOP Package Ordering Information TEMP. RANGE -40°C to +85°C PIN-PACKAGE 16 QSOP MAX1669EEE Applications Pentium®...