NCT1008: ±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.

Features
  • On-chip and remote temperature sensor
  • 0.25°C resolution/1°C accuracy on remote channel
  • 1°C resolution/1°C accuracy on local channel
  • Automatically cancels up to 1.5 kΩ (typical) of resistance in series with remote diode to allow noise filtering
  • Extended, switchable temperature measurement range 0°C to +127°C (default) or 64°C to +191°C
  • 2-wire SMBus serial interface with SMBus alert support
  • Programmable over/under temperature limits
  • Offset registers for system calibration
  • Up to two overtemperature fail-safe THERM outputs
  • Remote THERM Limit of 108°C
  • Compatible with 1.8 V Logic
Applications
  • Thermal Management
End Products
  • Notebook and Desktop Computers
  • Game Consoles
  • Servers
  • LCD TVs
  • Smart Electric Meters
  • Occupancy Sensors
  • DSL Line Cards
  • Graphics Cards
Application Notes (1)
Document TitleDocument ID/SizeRevisionRevision Date
Thermal Sensing Methods used in ON Semiconductor DevicesAND8494/D (137.0kB)0
Package Drawings (2)
Document TitleDocument ID/SizeRevision
DFN8 3x3, 0.5P506BJ (44.8kB)O
WDFN8 2x2, 0.5P511AT (61.2kB)O
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
±1 °C Temperature Sensor with Series Resistance CancellationNCT1008/D (327.0kB)6
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCT1008CMN3R2GLast ShipmentsPb-free Halide freeDFN-8506BJ1Tape and Reel3000
NCT1008CMT3R2GActivePb-free Halide freeWDFN-8511AT1Tape and Reel3000$0.6
NCT1008DMN3R2GLast ShipmentsPb-free Halide freeDFN-8506BJ1Tape and Reel3000
NCT1008DMT3R2GLifetimePb-free Halide freeWDFN-8511AT1Tape and Reel3000$0.6
Specifications
ProductSensor TypeData Transmission StandardICC Max (mA)VCC Min (V)VCC Max (V)T Min (°C)T Max (°C)Temperature Error (°C)
NCT1008CMT3R2GLocal & RemoteI2C0.352.83.6-40125±1
±1 °C Temperature Sensor with Series Resistance Cancellation (327.0kB) NCT1008
Thermal Sensing Methods used in ON Semiconductor Devices NCT1008
DFN8 3x3, 0.5P NCS2211
WDFN8 2x2, 0.5P NB3V60113G
NCT1008