ADT7421 Datasheet, PDF (1/20 Pages) ON Semiconductor – Precision Temperature Sensor with Beta Compensation (for <45 nm Geometries)

ADT7421
Precision Temperature
Sensor with Beta
Compensation
(for <45 nm Geometries)
The ADT7421 is a dual−channel digital thermometer and
under/overtemperature alarm, intended for use in PCs and thermal
management systems. It is pin− and register−compatible with the
ADM1032, ADT7461 and ADT7461A.
The ADT7421 includes Beta Cancellation Technology. This enables
accurate measurement of temperature from very small geometry
(45 nm) processes. Significant variations in the Beta factor can be
observed when different currents are applied to transistors embedded
in small geometry CPU’s. This leads to large temperature errors. The
ADT7421 automatically cancels the effects of error induced by beta
variations.
Features
• On−Chip and Remote Temperature Sensor
• 0.25°C Resolution on Remote Channel
• 1°C Resolution on Local Channel
• Automatically Cancels the Effect of Beta Variation in Thermal
Transistors on Small Geometry CPU’s
• Automatically Cancels Up to 50 W (Typical) of Resistance in Series
with Remote Transistor
• Extended, Switchable Temperature Measurement Range
0°C to +125°C (default) or −40°C to +125°C
• Pin− and Register−Compatible with ADM1032, ADT7461,
ADT7461A, EMC1402, and aSC7525
• 2−Wire SMBus 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 MSOP and SOP Packages
• These are Pb−Free Devices
Applications
• Desktop and Notebook Computers
• Industrial Controllers
• Smart Batteries
• Automotive
• Embedded Systems
• Burn−In Applications
• Instrumentation
http://onsemi.com
MARKING
DIAGRAMS
SOIC−8
1
CASE 751
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
R = SMBus Address
G = Pb−Free Package
8
T7421
ALYWRG
G
1
8
1
MSOP−8
CASE 846AB
L7x
AYWG
G
L7x = Refer to Ordering Table ¹
A = Assembly Location
Y = Year
W = Work Week
G = Pb−Free Package
(Note: Microdot may be in either location)
PIN ASSIGNMENT
V_DD 1
D+ 2
D– 3
THERM 4
8 SCLK
7 SDATA
6 ALERT/THERM2
5 GND
(Top View)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 18 of this data sheet.
© Semiconductor Components Industries, LLC, 2010
1
January, 2010 − Rev. 5
Publication Order Number:
ADT7421/D