|
|
PDF LM99CIMM Data sheet ( Hoja de datos )
| Número de pieza | LM99CIMM | |
| Descripción | 1C Accurate / High Temperature / Remote Diode Temperature Sensor with Two-Wire Interface | |
| Fabricantes | National Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LM99CIMM (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
July 2003
LM99
±1˚C Accurate, High Temperature, Remote Diode
Temperature Sensor with Two-Wire Interface
General Description
The LM99 is an 11-bit remote diode temperature sensor with
a 2-wire System Management Bus (SMBus) serial interface.
The LM99 accurately measures: (1) its own temperature and
(2) the temperature of a remote diode-connected transistor
such as the 2N3904 or a thermal diode commonly found on
Graphics Processor Units (GPU), Computer Processor Units
(CPU or other ASICs. The LM99 remote diode temperature
sensor shifts the temperature from the remote sensor down
16˚C and operates on that shifted temperature:
TACTUAL DIODE JUNCTION = TLM99 + 16˚C
The local temperature reading requires no offset.
The LM99 has an Offset Register which provides a means
for precise matching to various thermal diodes. Contact
hardware.monitor@nsc.com for the latest details.
The LM99 and LM99-1 have the same functions but different
SMBus slave addresses. This allows for one of each to be on
the same bus at the same time.
Activation of the ALERT output occurs when any tempera-
ture goes outside a preprogrammed window set by the HIGH
and LOW temperature limit registers or exceeds the T_CRIT
temperature limit. Activation of the T_CRIT_A occurs when
any temperature exceeds the T_CRIT programmed limit.
Features
n Accurately senses the temperature of remote diodes
n Offset register allows use of a variety of thermal diodes
n On-board local temperature sensing
n 10 bit plus sign remote diode temperature data format,
0.125 ˚C resolution
n T_CRIT_A output useful for system shutdown
n ALERT output supports SMBus 2.0 protocol
n SMBus 2.0 compatible interface, supports TIMEOUT
n 8-pin MSOP package
Key Specifications
j Supply Voltage
3.0 V to 3.6 V
j Supply Current
0.8 mA (typ)
j Local Temp Accuracy (includes quantization error)
TA = 25˚C to 125˚C ±3.0˚C (max)
j Remote Diode Temp Accuracy (includes quantization
error)
TA= 30˚C to 50˚C, TD= 120˚C to 140˚C
TA= 0˚C to 85˚C, TD= 25˚C to 140˚C
±1.0˚C (max)
±3.0˚C (max)
Applications
n Graphics Processor Thermal Management
n Computer Processor Thermal Management
n Electronic Test Equipment
n Office Electronics
Simplified Block Diagram
NVIDIA® is a registered trademark of NVIDIA Corporation.
GeForce™ is a trademark of NVIDIA Corporation.
Intel® and Pentium® are registered trademarks of Intel Corporation.
© 2003 National Semiconductor Corporation DS200538
20053801
www.national.com
1 page  
Logic Electrical Characteristics
DIGITAL DC CHARACTERISTICS Unless otherwise noted, these specifications apply for VDD = +3.0 to 3.6 Vdc. Boldface
limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = +25˚C, unless otherwise noted.
Symbol
Parameter
Conditions
Typical
Limits
Units
(Note 6)
(Note 7)
(Limit)
SMBData, SMBCLK INPUTS
VIN(1)
VIN(0)
VIN(HYST)
Logical “1” Input Voltage
Logical “0”Input Voltage
SMBData and SMBCLK Digital
Input Hysteresis
2.1 V (min)
0.8 V (max)
400 mV
IIN(1)
Logical “1” Input Current
IIN(0)
Logical “0” Input Current
CIN Input Capacitance
ALL DIGITAL OUTPUTS
VIN = VDD
VIN = 0 V
0.005
−0.005
5
±10 µA (max)
±10 µA (max)
pF
IOH
High Level Output Current
VOH = VDD
VOL SMBus Low Level Output Voltage IOL = 4 mA
IOL = 6 mA
10 µA (max)
0.4 V (max)
0.6
SMBus Digital Switching Characteristics
Unless otherwise noted, these specifications apply for VDD = +3.0 Vdc to +3.6 Vdc, CL (load capacitance) on output lines = 80
pF. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = +25˚C, unless otherwise noted. The switch-
ing characteristics of the LM99 fully meet or exceed the published specifications of the SMBus version 2.0. The following pa-
rameters are the timing relationships between SMBCLK and SMBData signals related to the LM99. They adhere to but are not
necessarily the SMBus bus specifications.
Symbol
Parameter
Conditions
Typical
Limits
Units
(Note 6)
(Note 7)
(Limit)
fSMB
SMBus Clock Frequency
100 kHz (max)
10 kHz (min)
tLOW
SMBus Clock Low Time
tHIGH
tR,SMB
tF,SMB
tOF
SMBus Clock High Time
SMBus Rise Time
SMBus Fall Time
Output Fall Time
tTIMEOUT
SMBData and SMBCLK Time Low for
Reset of Serial Interface (Note 14)
from VIN(0)max to
VIN(0)max
from VIN(1)min to VIN(1)min
(Note 12)
(Note 13)
CL = 400 pF,
IO = 3 mA, (Note 13)
1
0.3
4.7 µs (min)
25 ms (max)
4.0 µs (min)
µs (max)
µs (max)
250 ns (max)
25 ms (min)
35 ms (max)
tSU;DAT
tHD;DAT
Data In Setup Time to SMBCLK High
Data Out Stable after SMBCLK Low
250 ns (min)
300 ns (min)
900 ns (max)
tHD;STA
Start Condition SMBData Low to SMBCLK
Low (Start condition hold before the first
clock falling edge)
100 ns (min)
tSU;STO
Stop Condition SMBCLK High to SMBData
Low (Stop Condition Setup)
100 ns (min)
tSU;STA
SMBus Repeated Start-Condition Setup
Time, SMBCLK High to SMBData Low
0.6 µs (min)
tBUF SMBus Free Time Between Stop and Start
Conditions
1.3 µs (min)
5 www.national.com
5 Page 
1.0 Functional Description (Continued)
1.9 COMMUNICATING WITH THE LM99
The data registers in the LM99 are selected by the Com-
mand Register. At power-up the Command Register is set to
“00”, the location for the Read Local Temperature Register.
The Command Register latches the last location it was set
to. Each data register in the LM99 falls into one of four types
of user accessibility:
1. Read only
2. Write only
3. Read/Write same address
4. Read/Write different address
A Write to the LM99 will always include the address byte and
the command byte. A write to any register requires one data
byte.
Reading the LM99 can take place either of two ways:
1. If the location latched in the Command Register is cor-
rect (most of the time it is expected that the Command
Register will point to one of the Read Temperature Reg-
isters because that will be the data most frequently read
from the LM99), then the read can simply consist of an
address byte, followed by retrieving the data byte.
2. If the Command Register needs to be set, then an
address byte, command byte, repeat start, and another
address byte will accomplish a read.
The data byte has the most significant bit first. At the end of
a read, the LM99 can accept either Acknowledge or No
Acknowledge from the Master (No Acknowledge is typically
used as a signal for the slave that the Master has read its
last byte). It takes the LM99 31.25 ms to measure the
temperature of the remote diode and internal diode. When
retrieving all 10 bits from a previous remote diode tempera-
ture measurement, the master must insure that all 10 bits are
from the same temperature conversion. This may be
achieved by using one-shot mode or by setting the conver-
sion rate and monitoring the busy bit such that no conversion
occurs in between reading the MSB and LSB of the last
temperature conversion.
11 www.national.com
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet LM99CIMM.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LM99CIMM | 1C Accurate / High Temperature / Remote Diode Temperature Sensor with Two-Wire Interface | National Semiconductor |
| LM99CIMMX | 1C Accurate / High Temperature / Remote Diode Temperature Sensor with Two-Wire Interface | National Semiconductor |
| 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 |