ADT7483A Datasheet, PDF (1/24 Pages) Analog Devices – Dual Channel Temperature Sensor and Over Temperature Alarm

Dual Channel Temperature Sensor
and Over Temperature Alarm
ADT7483A
FEATURES
GENERAL DESCRIPTION
1 local and 2 remote temperature sensors
0.25°C resolution/1°C accuracy on remote channels
1°C resolution/1°C accuracy on local channel
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 2 overtemperature fail-safe THERM outputs
The ADT7483A¹ is a three-channel digital thermometer and
under/over temperature alarm, intended for use in PCs and
thermal management systems. It can measure the temperature
in two remote locations, for example, the remote thermal diode
in a CPU or GPU, or a discrete diode connected transistor. It can
also measure its own ambient temperature. The temperature of the
remote thermal diode and ambient temperature can be accurately
measured to ±1°C. The temperature measurement range defaults to
0°C to 127°C, compatible with ADM1032, but can be switched
Small 16-lead QSOP package
to a wider measurement range, from −64°C to +191°C.
240 μA operating current, 5 μA standby current
The ADT7483A communicates over a 2-wire serial interface
APPLICATIONS
compatible with system management bus (SMBus) standards.
The SMBus address is set by the ADD0 and ADD1 pins. As
Desktop and notebook computers
many as nine different SMBus addresses are possible.
Industrial controllers
Smart batteries
Automotive
Embedded systems
Burn-in applications
Instrumentation
An ALERT output signals when the on-chip or remote
temperature is outside the programmed limits. The THERM
output is a comparator output that allows, for example, on/off
control of a cooling fan. The ALERT output can be reconfigured
as a second THERM output, if required.
FUNCTIONAL BLOCK DIAGRAM
D1+ 3
D1– 4
D2+ 12
D2– 11
ON-CHIP TEMP
SENSOR
CONVERSION RATE
REGISTER
LOCAL TEMPERATURE
VALUE REGISTER
ANALOG
MUX
11-BIT A-TO-D
CONVERTER
BUSY RUN/STANDBY
REMOTE 1 AND 2 TEMP
VALUE REGISTERS
REMOTE 1 AND 2 TEMP
OFFSET REGISTERS
EXTERNAL DIODES OPEN-CIRCUIT
ADT7483A
STATUS REGISTERS
SMBus INTERFACE
ADDRESS POINTER
REGISTER
ONE-SHOT
REGISTER
LOCAL TEMPERATURE
THERM LIMIT REGISTER
LOCAL TEMPERATURE
LOW LIMIT REGISTER
LOCAL TEMPERATURE
HIGH LIMIT REGISTER
REMOTE 1 AND 2 TEMP
THERM LIMIT REGISTER
REMOTE 1 AND 2 TEMP
LOW LIMIT REGISTERS
REMOTE 1 AND 2 TEMP
HIGH LIMIT REGISTERS
CONFIGURATION
REGISTERS
INTERRUPT
MASKING
13 ALERT/THERM2
2
V_DD
6
GND
16
1
14
15
ADD0 ADD1 SDATA SCLK
5
THERM
Figure 1.
1 _{Protected by U.S. Patents 5,195,827, 5,867,012, 5,982,221, 6,097,239, 6,133,753, 6,169,442, other patents pending.}
©2008 SCILLC. All rights reserved.
February 2008 – Rev. 1
Publication Order Number:
ADT7483A/D