MAXIM Integrated Products, represented in Australia by Arrow Electronics , has released the MAX6678, a dual temperature sensor and fan controller. It offers remote temperature sensing up to 145°C and automatic adjustment of two cooling fans to minimise noise and improve efficiency.
It also has five general purpose I/O pins, which allow a user-programmable startup state without BIOS. It is suited to notebook and desktop computers where VID control, high efficiency, and low-noise operation are a priority.
The MAX6678 monitors the temperature of up to two external diode-connected transistors with ±1°C accuracy. The SMBus interface makes the data available to the system. The temperature data is also used by the internal PWM fan-speed controller to adjust the speed of two cooling fans, minimising unwanted fan noise and power drain when the system is running cool, but providing maximum cooling when required.
The fans can be programmed to operate with remote channel 1, remote channel 2, or both remote channels. Tachometer input of each fan is monitored to ensure correct operation. In the case of failures, fan drive is automatically removed and an alert signal can be generated. The GPIO pins can be used for setting POR states and controlling VID.
The system is targeted at portable applications where acoustic performance, high accuracy, and efficiency are at a premium. It is offered in the 20-pin QSOP package and operates from an input voltage range of 3V to 5.5V, using 500μA of supply current.