Semiconductor Components Industries, LLC, 2012
August, 2012 − Rev. 4
1 Publication Order Number:
NCT72/D
NCT72
+15C Temperature Monitor
with Series Resistance
Cancellation
The NCT72 is a dual-channel digital thermometer and
undertemperature/overtemperature alarm, intended for use in PCs and
thermal management systems. It is pin and register compatible with the
NCT1008 but the NCT72 allows the user to pull the ALERT
pin to
1.8 V without increasing the device Idd. A feature of the NCT72 is
series resistance cancellation, where up to 1.5 kW (typical) of resistance
in series with the temperature monitoring diode can be automatically
cancelled from the temperature result, allowing noise filtering. The
NCT72 has a configurable ALERT
output and an extended, switchable
temperature measurement range.
The NCT72 can measure the temperature of a remote thermal diode
accurate to 1C and the ambient temperature accurate to 3C. The
temperature measurement range defaults to 0C to +127C, compatible
with the NCT1008, but it can be switched to a wider measurement range
of −64C to +191C.
The NCT72 communicates over a 2-wire serial interface, compatible
with system management bus (SMBus/I
2
C) standards. The default
SMBus/I
2
C address of the NCT72 is 0x4C. An NCT72D is available
with an SMBus/I
2
C address of 0x4D. This is useful if more than one
NCT72 is used on the same SMBus/I
2
C.
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
0.25C Resolution/1C Accuracy on Remote Channel
1C Resolution/1C Accuracy on Local Channel
Series Resistance Cancellation Up to 1.5 kW
Extended, Switchable Temperature Measurement Range
0C to +127C (Default) or –64C to +191C
Pin and Register Compatible with NCT1008
Remote THERM Limit of 108C
2-wire SMBus/I
2
C Serial Interface with SMBus Alert Support
Programmable Over/Undertemperature Limits
Offset Registers for System Calibration
Up to Two Overtemperature Fail-safe THERM Outputs
Small 8-lead DFN
240 mA Operating Current, 5 mA Standby Current
Compatible with 1.8 V Logic
These Devices are Pb-Free, Halogen Free/BFR Free and are RoHS
Compliant
Applications
Smart Phones
Desktop and Notebook Computers
Smart Batteries
Automotive
Embedded Systems
MARKING DIAGRAMS
http://onsemi.com
PIN ASSIGNMENT
(Top View)
DFN8
CASE 506BJ
See detailed ordering and shipping information in the package
dimensions section on page 18 of this data sheet.
ORDERING INFORMATION
NCT
72x
ALYWG
G
1
8
x = C or D
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G = Pb-Free Package
(Note: Microdot may be in either location)
WDFN8
CASE 511AT
7xMG
G
1
SCLKV
DD
D+
D−
THERM
SDATA
ALERT
/
THERM2
GND
1
2
3
4
8
7
6
5
7x = Device Code (Where x = C or D)
M = Date Code
G = Pb-Free Package
WDFN8
DFN8
(Note: Microdot may be in either location)