MIC284-3BMM Micrel Inc, MIC284-3BMM Datasheet

no-image

MIC284-3BMM

Manufacturer Part Number
MIC284-3BMM
Description
IC SUPERVISOR THERM 2ZONE 8-MSOP
Manufacturer
Micrel Inc
Series
SilentSense™r
Datasheet

Specifications of MIC284-3BMM

Function
Temp Monitoring System (Sensor)
Topology
ADC (Sigma Delta), Comparator, Register Bank
Sensor Type
External & Internal
Sensing Temperature
-55°C ~ 125°C, External Sensor
Output Type
I²C™/SMBus™
Output Alarm
Yes
Output Fan
Yes
Voltage - Supply
2.7 V ~ 5.5 V
Operating Temperature
-55°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
General Description
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 I
or SMBus™ masters. Features include an open-drain over-
temperature output with dedicated registers for implementing
fan control or over-temperature shutdown circuits.
Interrupt status and mask bits are provided for reduced soft-
ware 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. The MIC284
is part of the SilentSense™ family of thermal supervisors.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Typical Application
SMBus and Pentium III are trademarks of Intel Corporation.
I
SilentSense is a trademark of Micrel, Inc.
September 2005
MIC284
2
C is a trademark of Philips Electronics, N.V.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
OVER-TEMP
SERIAL BUS
SHUTDOWN
FROM
HOST
3.3V
pull-ups
4  10k
2-Channel SMBus Temperature Measurement System
DATA
CLK
/INT
/CRIT
MIC284
2
C™
GND
VDD
T1
A0
1
Features
• Optimized for CPU Thermal Supervision in Computing
• 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
• Open-Drain Interrupt Output Pin
• Open-Drain Over Temperature Output Pin for Fan Con-
• 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
Applications
External Zones
trol or Hardware Shutdown
0.1F
Two-Zone Thermal Supervisor
2200pF
MIC284
REMOTE
DIODE
SilentSense™
Micrel, Inc.
MIC284

Related parts for MIC284-3BMM

MIC284-3BMM Summary of contents

Page 1

... 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. The MIC284 is part of the SilentSense™ family of thermal supervisors. ...

Page 2

... MIC284-0BM MIC284-0YM MIC284-1BM MIC284-1YM MIC284-2BM MIC284-2YM MIC284-3BM MIC284-3YM MIC284-0BMM MIC284-0YMM MIC284-1BMM MIC284-1YMM MIC284-2BMM MIC284-2YMM MIC284-3BMM MIC284-3YMM * The least-significant bit of the slave address is determined by the state of the A0 pin. Pin Configuration Pin Description Pin Number Pin Name 1 DATA 2 CLK 3 /INT 4 GND ...

Page 3

... GND 3 or GND 1 2.0 250 ±1 ±2 ±1 ≤ +85°C A ±2 50 100 224 7.5 14 2.0 10 ±0.01 Micrel, Inc. Max Units 750 µA µA 10 µA 200 µs 2 ±2 °C ±3 °C ±3 °C ±5 ° 160 ms 400 µA µA 0 ±1 µA MIC284 ...

Page 4

... Testing is performed using a single unit of one of the transistors listed in Table 6. D Note 6. Current into this pin will result in self-heating of the MIC284. Sink current should be minimized for best accuracy. Note 7. Guaranteed by design over the operating temperature range. Not 100% production tested. ...

Page 5

... MIC284 Timing Diagram SDA Data Out September 2005 t 1 SCL SDA Data Serial Interface Timing 5 Micrel, Inc MIC284 ...

Page 6

... Each MIC284 will only respond to its own unique slave address, allowing up to eight MIC284s to share a single bus. A match between the MIC284’s address and the address specified in the serial bit stream must be made to initiate communication. A0 should be tied directly to VDD or ground. See " ...

Page 7

... A new start bit must then be sent to the MIC284, followed by a repeat of the slave address with the R/W bit (LSB) set to the high (read) state. The data to be read from the part may then be clocked out ...

Page 8

... MIC284 MIC284 Table 2. MIC284 Register Addresses Micrel, Inc September 2005 ...

Page 9

... MIC284 September 2005 9 Micrel, Inc. MIC284 ...

Page 10

... MIC284 MIC284 10 Micrel, Inc September 2005 ...

Page 11

... 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 interrupted by a serial bus transaction as described above. Power-On When power is initially applied, the MIC284’s internal registers are set to their default states, and A0 is read to establish the device’ ...

Page 12

... Assuming the MIC284 is in interrupt mode and interrupts are enabled, there are five different conditions that will cause the MIC284 to set one of the status bits (S0, S1, or CRIT1) in CONFIG and assert its /INT output and/or /CRIT output. These conditions are listed in Table 5. When a tempera- ture event occurs, the corresponding status bit will be set in CONFIG ...

Page 13

... MIC284 September 2005 > > > > > > ° Table 5. MIC284 Temperature Events Micrel, Inc MIC284 ...

Page 14

... CONFIG Power-Up Value: 0000 0000 • not in shutdown mode • comparator mode • /INT = active low • Fault_Queue depth = 1 • interrupts enabled. • no temperature events pending CONFIG Command Byte Value: 0000 0001 * Following the first Fault_Queue conversions, one or more of the status bits may be set. MIC284 ...

Page 15

... Each LSB represents one degree Centigrade. The values are two's complement format such that 0°C is reported 0000 0000 See "Temperature Data Format" for more details See "Temperature Data Format" for more details See "Temperature Data Format" for more details. b Micrel, Inc. MIC284 ...

Page 16

... TEMP1 Power-Up Value: 0000 0000 TEMP1 Command Byte Value: 0001 0000 Remote Temperature Hysteresis Register T_HYST1 Power-Up Value: 0101 1100 T_HYST1 Command Byte Value: 0001 0010 Remote Temperature Setpoint Register T_SET1 Power-Up Value: 0110 0001 T_SET1 Command Byte Value: 0001 0011 MIC284 ...

Page 17

... (+97°C) * Each LSB represents one degree Centigrade. The values are two's complement format such that 0°C is reported as h 0000 0000 See "Temperature Data Format" for more details See "Temperature Data Format" for more details. b Micrel, Inc. MIC284 ...

Page 18

... In order to understand external diode will cause an error in the temperature reading from the MIC284. A good rule of thumb is this: for each ohm in series with the external transistor, there will be a 0.9°C error in the MIC284’s temperature measurement. It isn’t difficult to keep the series resistance well below an ohm (typically < ...

Page 19

... MIC284 1. Place the MIC284 as close to the remote diode as possible, while taking care to avoid severe noise sources such as high frequency power transformers, CRTs, memory and data busses, and the like. 2. Since any conductance from the various volt- ages on the PC Board and the T1 line can in- duce serious errors good practice to guard the remote diode’ ...

Page 20

... Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Pr MIC284 8-Lead SOIC (M) 8-Lead MSOP (MM) ...

Related keywords