|
|
PDF MIC284-0BMM Data sheet ( Hoja de datos )
| Número de pieza | MIC284-0BMM | |
| Descripción | Two-Zone Thermal Supervisor Advance Information | |
| Fabricantes | Micrel Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de MIC284-0BMM (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
MIC284
MIC284
Two-Zone Thermal Supervisor
Advance Information
Micrel
General Description
Features
The MIC284 is a versatile digital thermal supervisor capable
of measuring temperature using its own internal sensor and
an inexpensive external sensor or embedded silicon diode
such as those found in the Intel Pentium III* CPU. A 2-wire
serial interface is provided to allow communication with either
I2C** or SMBus* masters. Features include an open-drain
over-temperature output with dedicated registers for imple-
menting fan control or over-temperature shutdown circuits.
Interrupt status and mask bits are provided for reduced
software overhead. The open-drain interrupt output pin can
be used as either an overtemperature alarm or a thermostatic
control signal. A programmable address pin permits two
devices to share the bus. (Alternate base addresses avail-
able-contact Micrel.) Superior performance, low power and
small size makes the MIC284 an excellent choice for the most
demanding thermal management applications.
*SMBus and Pentium III are trademarks of Intel Corporation.
**I2C is a trademark of Philips Electronics, N.V.
Ordering Information
• Optimized for CPU Thermal Supervision in Computing
Applications
• Measures Local and Remote Temperature
• Sigma-Delta ADC for 8-Bit Temperature Results
• 2-Wire SMBus-compatible Interface
• Programmable Thermostat Settings for both Internal and
External Zones
• Open-Drain Interrupt Output Pin
• Open-Drain Over Temperature Output Pin for Fan
Control or Hardware Shutdown
• Interrupt Mask and Status Bits
• Low Power Shutdown Mode
• Failsafe response to diode faults
• 2.7V to 5.5V Power Supply Range
• 8-Lead SOIC and MSOP Packages
Applications
• Desktop, Server and Notebook Computers
• Power Supplies
• Test and Measurement Equipment
• Wireless Systems
• Networking/Datacom Hardware
Part Number
Base Address(*)
Junction Temp. Range
Package
MIC284-0BM
100 100x
–55°C to +125°C
8-Lead SOP
MIC284-1BM
100 101x
–55°C to +125°C
8-Lead SOP
MIC284-2BM
100 110x
–55°C to +125°C
8-Lead SOP
MIC284-3BM
100 111x
–55°C to +125°C
8-Lead SOP
MIC284-0BMM
100 100x
–55°C to +125°C
8-Lead MSOP
MIC284-1BMM
100 101x
–55°C to +125°C
8-Lead MSOP
MIC284-2BMM
100 110x
–55°C to +125°C
8-Lead MSOP
MIC284-3BMM
100 111x
–55°C to +125°C
8-Lead MSOP
* The least-significant bit of the slave address is determined by the state of the A0 pin.
Notes
Contact Factory
Contact Factory
Contact Factory
Contact Factory
Contact Factory
Contact Factory
Typical Application
3.3V
4 × 10k
pull-ups
FROM
SERIAL BUS
HOST
OVER-TEMP
SHUTDOWN
MIC284
DATA
VDD
CLK
T1
/INT
A0
/CRIT
GND
0.1µF
2200pF
REMOTE
DIODE
2-Channel SMBus Temperature Measurement System
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
September 29, 2000
1
MIC284
1 page  
MIC284
Micrel
Note 1.
Note 2.
Note 3.
Note 4.
Note 5.
Note 6.
Note 7.
Note 8.
Note 9.
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended.
Human body model: 1.5k in series with 100pF. Machine model: 200pF, no series resistance.
Final test on outgoing product is performed at TA = TBD°C.
TD is the temperature of the remote diode junction. Testing is performed using a single unit of one of the transistors listed in Table 6.
Current into this pin will result in self-heating of the MIC284. Sink current should be minimized for best accuracy.
Guaranteed by design over the operating temperature range. Not 100% production tested.
tCONV = tCONV0 + tCONV1. tCONV0 is the conversion time for the local zone; tCONV1 is the conversion time for the remote zone.`
Accuracy specification does not include quantization noise, which may be as great as ±1⁄2LSB (±0.5°C).
Timing Diagram
SCL
SDA Data In
t4
SDA Data Out
t1
t2
t3
Serial Interface Timing
t5
September 29, 2000
5
MIC284
5 Page 
MIC284
Temperature Data Format
The LSB of each register represents one degree Centigrade.
The values are in a two’s complement format, wherein the
most significant bit (D7), represents the sign: zero for positive
temperatures and one for negative temperatures. Table 3
shows examples of the data format used by the MIC284 for
temperatures.
A/D Converter Timing
Whenever the MIC284 is not in its low power shutdown mode,
the internal A/D converter (ADC) attempts to make continu-
ous conversions unless interrupted by a bus transaction
accessing the MIC284. When the part is accessed, the
conversion in progress will be halted, and the partial result
discarded. When the access to the MIC284 is complete, the
ADC will begin a new conversion cycle with results for the
remote zone valid tCONV1 after that, and for the local zone
tCONV0 later. Figure 4 shows this behavior. The conversion
time is twice as long for external conversions as it is for
internal conversions. This allows the use of a filter capacitor
on T1 without a loss of accuracy due to the resulting longer
settling times.
Upon powering-up, coming out of shutdown mode, or resum-
ing operation following a serial bus transaction, the ADC will
begin acquiring temperature data starting with the external
zone (zone 1), followed by the internal zone (zone 0). If the
ADC is interrupted by a serial bus transaction, it will restart the
conversion that was interrupted and then continue in the
normal sequence. This sequence will repeat indefinitely until
the MIC284 is shut down, powered off, or is interrupted by a
serial bus transaction as described above.
Power-On
When power is initially applied, the MIC284’s internal regis-
ters are set to their default states, and A0 is read to establish
the device’s slave address. The MIC284’s power-up default
state can be summarized as follows:
• Normal Mode operation (i.e., part is not in shut-
down)
• /INT function is set to Comparator Mode
• Fault Queue depth = 1 (FQ=00)
• Interrupts are enabled (IM = 0)
• T_SET0 = 81°C; T_HYST0 = 76°C
• T_SET1 = 97°C; T_HYST1 = 92°C
• CRIT1 = 97°C; nCRIT1 = 92°C
• Initialized to recognize overtemperature faults
Micrel
Comparator and Interrupt Modes
Depending on the setting of the MODE bit in the configuration
register, the /INT output will behave either as an interrupt
request signal or a thermostatic control signal. Thermostatic
operation is known as comparator mode. The /INT output is
asserted when the measured temperature, as reported in
either of the TEMPx registers, exceeds the threshold pro-
grammed into the corresponding T_SETx register for the
number of conversions specified by Fault_Queue (described
below). In comparator mode, /INT will remain asserted and
the status bits will remain high unless and until the measured
temperature falls below the value in the T_HYSTx register for
Fault_Queue conversions. No action on the part of the host
is required for operation in comparator mode. Note that
entering shutdown mode will not affect the state of /INT when
the device is in comparator mode.
In interrupt mode, once a temperature event has caused a
status bit (Sx) to be set, and the /INT output to be asserted,
they will not be automatically de-asserted when the mea-
sured temperature falls below T_HYSTx. They can only be
de-asserted by reading any of the MIC284’s internal registers
or by putting the device into shutdown mode. If the most
recent temperature event was an overtemperature condition,
Sx will not be set again, and /INT cannot be reasserted, until
the device has detected that TEMPx < T_HYSTx. Similarly,
if the most recent temperature event was an undertemperature
condition, Sx will not be set again, and /INT cannot be
reasserted, until the device has detected that TEMPx >
T_SETx. This keeps the internal logic of the MIC284 back-
ward compatible with that of the LM75 and similar devices. In
both modes, the MIC284 will be responsive to over-tempera-
ture events at power-up. See "Interrupt Generation", below.
Shutdown Mode
Setting the SHDN bit in the configuration register halts the
otherwise continuous conversions by the A/D converter. The
MIC284’s power consumption drops to 1µA typical in shut-
down mode. All registers may be read from or written to while
in shutdown mode. Serial bus activity will slightly increase the
part’s power consumption.
Entering shutdown mode will not affect the state of /INT when
the device is in comparator mode (MODE = 0). It will retain
its state until after the device exits shutdown mode and
resumes A/D conversions.
September 29, 2000
Temperature
Binary
Hex
+125° C
+25° C
+1.0° C
0° C
– 1.0° C
– 25° C
– 40° C
– 55° C
0111 1101b
0001 1001b
0000 0001b
0000 0000b
1111 1111b
1110 0111b
1101 1000b
1100 1001b
7Dh
19h
01h
00h
FFh
E7h
D8h
C9h
Table 3. Digital Temperature Format
11
MIC284
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet MIC284-0BMM.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MIC284-0BM | Two-Zone Thermal Supervisor Advance Information | Micrel Semiconductor |
| MIC284-0BMM | Two-Zone Thermal Supervisor Advance Information | Micrel 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 |