|
|
PDF ADT7461A Data sheet ( Hoja de datos )
| Número de pieza | ADT7461A | |
| Descripción | Temperature Monitor | |
| Fabricantes | Analog Devices | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de ADT7461A (archivo pdf) en la parte inferior de esta página. Total 24 Páginas | ||
|
No Preview Available !
www.DataSheet4U.com
±1°C Temperature Monitor with Series
Resistance Cancellation
ADT7461A
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
Pin- and register-compatible with ADM1032 and ADT7461
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
Small 8-lead MSOP
240 μA operating current, 5 μA standby current
APPLICATIONS
Desktop and notebook computers
Industrial controllers
Smart batteries
Automotive
Embedded systems
Burn-in applications
Instrumentation
FUNCTIONAL BLOCK DIAGRAM
ON-CHIP
TEMPERATURE
SENSOR
CONVERSION RATE
REGISTER
LOCAL TEMPERATURE
VALUE REGISTER
D+ 2
D– 3
ANALOG
MUX
A-TO-D
CONVERTER
BUSY RUN/STANDBY
REMOTE TEMPERATURE
VALUE REGISTER
REMOTE OFFSET
REGISTER
EXTERNAL DIODE OPEN-CIRCUIT
ADT7461A
1
VDD
5
GND
STATUS REGISTER
SMBus INTERFACE
ADDRESS POINTER
REGISTER
LOCAL TEMPERATURE
LOW-LIMIT REGISTER
LOCAL TEMPERATURE
HIGH-LIMIT REGISTER
REMOTE TEMPERATURE
LOW-LIMIT REGISTER
REMOTE TEMPERATURE
HIGH-LIMIT REGISTER
LOCAL THERM LIMIT
REGISTERS
EXTERNAL THERM LIMIT
REGISTERS
CONFIGURATION
REGISTERS
INTERRUPT
MASKING
7
SDATA
8
SCLK
Figure 1.
6 ALERT/THERM2
4 THERM
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2006 Analog Devices, Inc. All rights reserved.
1 page  
ADT7461A
SMBUS TIMING SPECIFICATIONS
Table 3.
Parameter1
Limit at TMIN and TMAX
fSCLK 400
tLOW 1.3
tHIGH
0.6
tR 300
tF 300
tSU; STA
tHD; STA2
t3
SU; DATT
tSU; STO4
600
600
100
600
tBUF 1.3
1 Guaranteed by design, but not production tested.
2 Time from 10% of SDATA to 90% of SCLK.
3 Time for 10% or 90% of SDATA to 10% of SCLK.
4 Time for 90% of SCLK to 10% of SDATA.
Unit
kHz max
μs min
μs min
ns max
ns max
ns min
ns min
ns min
ns min
μs min
Description
Clock low period, between 10% points
Clock high period, between 90% points
Clock/data rise time
Clock/data fall time
Start condition setup time
Start condition hold time
Data setup time
Stop condition setup time
Bus free time between stop and start conditions
TIMING DIAGRAM
SCLK
SDATA
tBUF
STOP START
tLOW
tR
tHD;STA
tHD;DAT
tF
tHIGH
tSU;DAT
tHD;STA
tSU;STA
START
Figure 2. Serial Bus Timing
tSU;STO
STOP
Rev. A | Page 5 of 24
5 Page 
VDD
I N1 × I N2 × I IBIAS
ADT7461A
REMOTE
SENSING
TRANSISTOR
D+
C11
D–
BIAS
DIODE
LPF
fC = 65kHz
VOUT+
TO ADC
VOUT–
1CAPACITOR C1 IS OPTIONAL. IT IS ONLY NECESSARY IN NOISY ENVIRONMENTS. C1 = 1000pF MAX.
Figure 15. Input Signal Conditioning
TEMPERATURE MEASUREMENT RESULTS
The results of the local and remote temperature measurements
are stored in the local and remote temperature value registers
and compared with limits programmed into the local and
remote high and low limit registers.
The local temperature value is in Register 0x00 and has a
resolution of 1°C. The external temperature value is stored in
two registers, with the upper byte in Register 0x01 and the
lower byte in Register 0x10. Only the two MSBs in the external
temperature low byte are used giving the external temperature
measurement a resolution of 0.25°C. Table 7 lists the data
format for the external temperature low byte.
Table 7. Extended Temperature Resolution
(Remote Temperature Low Byte)
Extended Resolution Remote Temperature Low Byte
0.00°C
0 000 0000
0.25°C
0 100 0000
0.50°C
1 000 0000
0.75°C
1 100 0000
When reading the full external temperature value, read the LSB
first. This causes the MSB to be locked (that is, the ADC does
not write to it) until it is read. This feature ensures that the
results read back from the two registers come from the same
measurement.
TEMPERATURE MEASUREMENT RANGE
The temperature measurement range for both internal and
external measurements is, by default, 0°C to +127°C. However,
the ADT7461A can be operated using an extended temperature
range. The extended measurement range is −64°C to +191°C.
Therefore, the ADT7461A can be used to measure the full
temperature range of an external diode, from −55°C to +150°C.
The extended temperature range is selected by setting Bit 2 of
the configuration register to 1. The temperature range is 0°C
to 127°C when Bit 2 equals 0. A valid result is available in the
next measurement cycle after changing the temperature range.
In extended temperature mode, the upper and lower temperature
that can be measured by the ADT7461A is limited by the
remote diode selection. The temperature registers can have
values from −64°C to +191°C. However, most temperature
sensing diodes have a maximum temperature range of −55°C to
+150°C. Above +150°C, they may lose their semiconductor
characteristics and approximate conductors instead. This results
in a diode short. In this case, a read of the temperature result
register gives the last good temperature measurement. Therefore,
the temperature measurement on the external channel may not
be accurate for temperatures that are outside the operating range
of the remote sensor.
It should be noted that although both local and remote temperature
measurements can be made while the part is in extended
temperature mode, the ADT7461A itself should not be exposed to
temperatures greater than those specified in the absolute maximum
ratings section. Further, the device is only guaranteed to operate as
specified at ambient temperatures from −40°C to +120°C.
TEMPERATURE DATA FORMAT
The ADT7461A has two temperature data formats. When the
temperature measurement range is from 0°C to 127°C (default),
the temperature data format for both internal and external
temperature results is binary. When the measurement range is
in extended mode, an offset binary data format is used for both
internal and external results. Temperature values are offset by
64°C in the offset binary data format. Examples of temperatures
in both data formats are shown in Table 8.
Rev. A | Page 11 of 24
11 Page | ||
| Páginas | Total 24 Páginas | |
| PDF Descargar | [ Datasheet ADT7461A.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| ADT7461 | Temperature Monitor | Analog Devices |
| ADT7461 | Temperature Monitor |  ON Semiconductor |
| ADT7461A | Temperature Monitor | ON Semiconductor |
| ADT7461A | Temperature Monitor | Analog Devices |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |