±1°C Digital Temperature Sensor with Series Resistance Cancellation

The NCT1008 is a dual-channel digital temperature sensor intended for use in elevated thermal density applications. A feature of the NCT1008 is series resistance cancellation, where up to 1.5 kΩ of resistance in series with the temperature monitoring diode can be automatically cancelled from the temperature result, allowing noise filtering. The NCT1008 has a configurable ALERT output and an extended, switchable temperature measurement range. The NCT1008 can measure the temperature of a remote thermal diode accurate to ±1°C and the ambient temperature accurate to ±3°C. The temperature measurement range defaults to 0°C to +127°C, compatible with the ADM1032, but it can be switched to a wider measurement range of -64°C to +191°C. The NCT1008 communicates over a 2-wire serial interface, compatible with system management bus (SMBus/I2C) standards. The default SMBus/I2C address of the NCT1008 is 0x4C. An NCT1008D is available with an SMBus/I2C address of 0x4D. This is useful if more than one NCT1008 is used on the same SMBus/I2C. An ALERT output signals when the on-chip or remote temperature is out of range. The THERM output is a comparator output that allows on/off control of a cooling fan. The ALERT output can be reconfigured as a second THERM output, if required.