General description

lm95221 is a MSOP software package with a double remote diode temperature sensor. The 2 -line serial interface LM95221 is compatible with SMBUS 2.0. LM95221 cans three temperature areas, which can measure the temperature of its own mold and the transistor connected to the two diode. The transistor connected by the diode can be a thermal diode discovered in the Pentium and AMD processor, or the MMBT3904 transistor that can be simply connected to the diode. The LM95221 parsing format of the remote temperature read can be programmed as 10 -bit or 11 unsatient symbols. In the non -symbolic mode LM95221 remote diode reading, the temperature can resolve the temperature higher than 127 ° C. The resolution of the local temperature reading is 9 digits. The temperature of any ASIC can accurately determine that as long as there is a dedicated diode (semiconductor knot) on the target chip, LM95221 can be used. LM95221 remote sensor accuracy is ± 1 ; C is adjusted to series resistance to 2.7 ohm, and the non -ideal coefficient is 1.008.

Feature

Accurately perceive the mold temperature or diode knot of the remote IC

Remote diode fault detection

Local temperature sensing of the car

[123 ] Remote temperature reading: -0.125 degrees Celsius LSB-programmable resolution 11-bit plus 10-bit symbol-11-bit analysis of temperature higher than 127 ° C

Local temperature reading: -0.25 degrees Celsius-9 plus number [ 123]

Status register supports

The programmable conversion rate allows users to optimize

Electricity consumption

Disclosure mode Conversion control

SMBUS 2.0 compatibility Interface, support timeout

8 -needle MSOP packaging

Main specifications

Local temperature accuracy

ta 0 ; C to 85 ; C ± 3.0 ; C (maximum value)

The temperature accuracy of the remote diode

TA 30 degrees Celsius to 50 degrees Celsius, TD 45 degrees Celsius to 85 degrees Celsius ± 1.0 degrees Celsius (maximum) [123) [123) [123) [123) [123) [123) [123) [123) ]

TA 0 ; C to 85 ; C, TD 25 ; C to 140 ; C ± 3.0 ; C (maximum)

Power voltage 3.0 V

Electronic testing equipment

Office electronic equipment

Absolute maximum rated value (Note 1)

Power voltage 0.3 V to 6.0 v

The voltage at SMBDAT, SMBCLK 0.5V to 6.0V

Voltage at other stitches 0.3 v ]

D input current ± 1 ma

All other pins input current (Note 2) ± 5 ma

Input current of the unit (Note 2) 30 ma [123 ]

SMBDAT output leakage current 10 mAh

Storage temperature 65 ; C to+150 ; c

Welding information, lead temperature

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123] MSOP-8 Pack (Note 3)

Qi Phase (60 seconds) 215 ; C

Infrared (15 seconds) 220 ; c

Static discharge discharge discharge Sensitivity (Note 4)

Human model 2000V

Machine model 200 v

Operating rated value (Note 1, 5)

Work temperature range 0 #730; C to+115 ; C

Electrical characteristics

Temporary range tmin ≤TA ≤TMAX

lm95221cmm 0 ; C≤ta ≤+85 # 730; C

Power voltage range (VDD)+3.0V to+3.6V

Temperature-Digital converter characteristics

Unless otherwise explained, these specifications are applicable to VDD +3.0VDC to 3.6VDC. Black body limit is suitable for ta tj tmin≤TA ≤TMAX; all other limit ta TJ +25 ; C, unless otherwise explained. TJ is the knot temperature of LM95221. TD is the knot temperature of the remote heat diode.

Logical electrical characteristics

DC characteristics unless otherwise explained, these specifications are suitable for VDD +3.0 to 3.6 VDC. Black body Lim is suitable for TA TJ TMIN to TMAX; all other limit ta TJ +25 ; C, unless otherwise explained.

Unless otherwise explained, these specifications are applicable to VDD +3.0 VDC to +3.6 VDC, CL (load capacitor), output cable 80 pF. Black body limit is suitable for TA TJ TMIN to TMAX; all other limit ta TJ +25 ; C, unless otherwise explained. The exchange characteristics of LM95221 have completely met or exceeded the release specifications of the SMBUS 2.0 version. The following parameters are the time -sequential relationship between SMBCLK and SMBDAT SIG related to LM95221. They follow but not necessarily SMBUS bus specifications.

Note 1: Absolute maximum rated value indicates the limit of damage to the device. During operation, DC and AC electrical specifications are not applicable to device exceeding its rated working conditions.

Note 2: When the input voltage (VI) of any pin exceeds the power supply (VI LT; GND or VI GT; VDD), the current of the pin should be limited to 5 mA. The parasitic elements and/or ESD protection circuits of LM95221 pins are shown in the figure below. The nominal breakdown voltage of D4 is 6.5 V. Be careful not to cause the parasitic diode D1 on the pins D1+: D1+, D2+, D1-, D2-. If more than 50 mv, it may damage the temperature measurement.

Note: X indicates that there are components in the specified pin. SNP refers to a rebate device.

Note 3: Please refer to the URL /Packaging/other suggestions and methods welded surface installation equipment.

Note 4: Human model, 100pf passed 1.5 through 1.5 k resistance power. Machine model, 200pf discharged directly to each pin.

Note 5: When connected to the printing circuit board with 2 ounces of foil, connect to the heat resistance of the environment: - MSOP-8 210 ; C/W

Note 6: The typical value is TA 25 ° C, which represents the most likely parameter standard. National AOQL (the average factory quality level).

Note 8: Local temperature accuracy does not include the self -heating effect. The temperature increase caused by the heating is the loss and thermal resistance of the product of the internal power LM95221. 5).

Note 9: When the use of the non -ideal degree of 1.008 and the series R 2.7 heat diode, the accuracy of LM95221CIMM is guaranteed. Will offset -3.25 ; C

Note 10: When using SMBU, the static current will not increase significantly.

Note 11: This specification is only used to explain the update frequency of temperature data .Lm95221 can be in anyReading without considering the conversion state (and the final conversion result will be generated).

Note 12: Output rising time from (VIN (0) maximum value+0.15V) to (VIN (1) minimum value 0.15V).

Note 13: The output drop time is measured from (1) min-0.15V) to (VIN (1) min+0.15V).

Note 14: The time interval between the SMBDAT and/or SMBCLK line at the low level is greater than that of TTIMEOUT, which will reset the SMBUS state machine of LM95221, so SMBDAT and SMBCLK pins are in high impedance state.

Typical performance features

Function description

LM95221 is a digital sensor, which can be detected by Sigma-Delta modulus converter 3 Temperature converter in the heat area. It can measure the temperature of its local mold temperature and the temperature of the MMBT3904 transistor connected by the two diode. 2 -line serial LM95221 interfaces with SMBUS 2.0 and I2C. For details, see SMBUS 2.0 specification I2C bus and SMBUS. The temperature conversion rate programmable user optimizes the current consumption of LM95221 to meet the system requirements. LM95221 can be placed when the temperature data is not required, and the power consumption is reduced to maximize the power consumption. In the shutdown state, the single conversion mode allows the system to control the conversion rate to the ultimate flexibility. The temperature resolution of the remote diode is 11 digits of 11 digits of 11 digits or 10 digits. The minimum effective position (LSB) weight of the two resolution is 0.125 ° C. The non -symbol resolution allows the remote diode sensing temperature to be higher than 127 ° C. The local temperature resolution is not programmable, and the minimum temperature of the 9 -bit plus number is always 0.25 degrees Celsius. The temperature accuracy of the long -range diode of LM95221 is the thermal diode of the Proskot processor and only when using this diode to ensure accuracy. The diode fault detection circuit in LM95221 can detect whether there is a remote diode: whether D+is short-circuited for VDD, D-or ground, or whether D+floats. LM95221 register set has 8 -bit data structure and

includes:

1. The highest effective byte (MSB) Local temperature register

2. The lowest effective byte (LSB) (LSB) Local temperature register

3.MSB remote temperature 1 register

4.LSB remote temperature 1 register

5.MSB remote temperature 2 register

6. LSB remote temperature 2 register

Function description (continued)

7. Status register: busy, Diodes fault

8. Configuration register: resolution control, conversion rate control, backup control

9. Single register

10. Manufacturer ID

[ 123] 11. Fixed ID

Conversion order

LM95221 Convert local temperature, remote temperature 1 and 2, and all the registers that update it. Only in the conversion process, the busy position (D7) in the status register (02H) is a high level. These conversions are processed in a circular order. The conversion rate can be modified by the conversion rate in the configuration register (03H). When the conversion rate is modified, a delay is inserted between the conversion, and the actual conversion time is maintained at 66ms (each remote 26 ms and the local 14 ms). Different conversion rates will cause LM95221 to draw different current supply as shown in Figure 2.

The default status of the boot

lm95221 is always power -based to these known default status. LM95221 in these states until the first conversion.

1. The command register is set to 00h

2. The local temperature is set to 0 ; c

3. The temperature of the remote diode is 0 ; The first conversion

4. The state register depends on the state of the input of the thermal diode

5. Configure the register set to 00H; continuous conversion, time 66ms

SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS interface [SMBUS intermi 123]

SMB221 is operated on LMU, so the SMBCLK line is an input, and the SMBDAT line is two -way. LM95221 never drives the SMBCLK series and it does not support clock stretching. According to SMBUS specifications, LM95221 has a 7 -bit portal address. The full part of A6 to A0 is internal programming and cannot be changed by software or hardware. LM95221 has the following SMBUS subordinate address:

Temperature data format

Temperature data can only be from local and remote temperature registers. The remote temperature data is equal to 0.125 ° C by a 11 -bit 2 -bit complement word or non -symbolic binary word (minimum effective position). The data format is available in the left -to -Qi 16 -bit characters in two 8 -bit registers. Unused bit will always report 0 .

Local temperature data is represented by 10 -bit 2

LSB (minimum effective position) complement code 0.25 ° C. The data format is a 16 -bit word left, which can be used in two 8 -bit registers. Unused bit will always report 0 . The local temperature reading of the local temperature of+127.875 ; C is held to+127.875 ;At the time of C, the temperature reading will be negative.

SMBDAT opens the output

SMBDAT output is an open leak output, not internal tracts. The height level is not observed on the top until the pull -up current is a power supply provided by the outside, usually a pull -up resistor. The choice of resistance values u200bu200bdepends on many system factors, but generally speaking, the pull -up resistor should be as large as possible without affecting the data rate required by SMBUS. This will minimize the temperature reading caused by any internal heating LM95221. The maximum resistance of pulling is 2.1V high level, and the level output current based on the voltage of the LM95221 specification is 3.0V is

82K (5%) or 88.7k (1%) Essence

Diodes fault detection

LM95221 is equipped with a designed operating circuit detection of the failure of the remote control diode. In the detection of D+tactile short -circuit events, D , VDD or D+floating, the remote temperature reading is -128.000 ; In addition, properly set the status storage position RD1M or RD2M (D1 or D0).

Communication with LM95221

The data register in LM95221 is commanded by the command register. When powering, the command register is set to 00 , and the location of the local temperature is registered. The last position of the command register locks it. Each data register in lm95221 is classified as a four types of user accessability:

1. Read only

2. Only write

3. Read/write/write The same address

4. Write/read different addresses

Writing address 221 always contains LMA address and command bytes. The writing of any register requires a data byte.

Reading LM95221 can be performed in two ways:

1. If the position is locked in the command register is correct (in most cases, the most commonly read in the command register is read. The temperature point is from LM95221), so reading can simply include address bytes, and then retrieve data bytes.

2. If the command register is needed, the address byte byte, command byte, repeated startup, and other address bytes will be read. Data bytes are first of all effective positions. At the end, LM95221 can accept confirmation or whether it is confirmed from the host (usually not recognized as a signal from the device, the main device has read its last byte). It requires LM95221 6666666666666666666666666666666666666666666666 66 milliseconds to measure remote diode and internal twoThe temperature of the polar tube. Searched all 11 bits from the previous remote diode temperature measurement, and the host must ensure that all 11 bits were converted from the same temperature. This may be achieved by reading the MSB register first. LSB will be locked after reading MSB. LSB will be reading. If the user reads MSB continuously, every time you read the MSB, the LSB and the temperature association will be locked and covered with the previous LSB value.

Function description (continued)

Serial interface reset

If SMBUS main server is transmitted on the SMBDAT line on LM95221, that is, LM95221 The known state protocol in communication must be returned. This can be performed through one of the following two methods:

1. When SMBDAT is low, the LM95221 SMBUS state If SMB DAT or SMBCLK keeps a low level of more than 35MS, the computer is reset to SMBUS idle state (T time) Essence Note that according to the SMBUS specification

when SMBCLK

or SMBDAT lines remain low 25-35ms. Therefore, to ensure that all devices on the bus SMBCLK or SMBDAT lines must be maintained at least 35ms at a low level.

2. When the SMBDAT is high, let the host start the SMBUS start. LM95221 will respond to the SMBUS startup condition at any point in the communication process. After starting, LM95221 will need a SMBU address byte.

One -time conversion

One -time register is used to start a single conversion and the device is in a standby state. After that, the device will return to the standby state. This is not a data register, it is a single trigger writing operation conversion. The data and unsatisfactory storage of this address. The register will always read 0

lm95221 register

The command register select which register to read or write from which register. The data of this register should be written to the command by SMBUS.

Temperature data: LSB 0.125 ; C.

For the purpose of data synchronization, if the user wants to read MSB and LSB registers at the same time, the MSB register should be read first.

After reading MSB, LSB will be locked. LSB will be unlocked after reading. If the user reads MSB continuously, the previous LSB value is covered in LSB, and each LSB will be locked.

Application prompts

LM95221 usage method and other integrated circuit temperature sensors and other integrated circuit temperature sensors and other integrated circuit temperature sensorsIts remote control diode induction capacity allows it to use in a new way. It can be welded on the printing circuit board, because the best thermal guidance path is in the mold and sales, and its temperature will effectively print the circuit board welding to LM95221. This assumes that the air temperature of the environment is almost equal to the printing circuit board; if the air temperature is much higher or lower than the surface temperature, the actual temperature of the LM95221 mold will be in the middle temperature between the surface temperature and the air temperature. Besides, the main thermal conduction path is through the lead, so the effect of circuit board temperature on the mold temperature is much greater than the temperature temperature. To measure the temperature outside the LM95221 mold, use a remote control diode. This diode can be located at the target IC, allowing the temperature of the IC to measure IC, which has nothing to do with the temperature of LM95221. LM95221 has been optimized to measure the non -ideal value of the remote thermal diode of 1.008, and the series resistance is 2.7 The typical non -ideal of the thermist diode process on the 90 -nanometer Pentium 4 processor is 1.011 series resistance is 3.33 Therefore, when measured this value, the thermist diode with LM95221 typical bias+1.5 ; C will be observed. This offset can be easily compensated to minus 1.5 degrees Celsius from the reading of LM95221. The discrete diode can also be used to sense external temperature objects or environmental air. Remember that the temperature of the discrete diode will receive the temperature of the wire. Most silicon diodes are not suitable for this application. It is recommended that 2N3904 transistor radiosis and base. When the diode connected to the 2N3904 diode LM95221, the offset of -3.25 ; C will be observed. This offset can be simply added to LM95221 Reading: T2N3904 TLM95221+3.25 ; C

Diodes Non -idealistic

The impact of non -ideal factors diode on the accuracy

The relationship between VBE, T and IF when the transistor is connected as a diode

q 1.6x10 19 123] t Absolute temperature (Kaijizhi)

k 1.38x10 23 Jiao Er/K (Bolzman Num)

η is a non -ideal factor in the diode process [ 123]

Manufacturing date: IS saturated current, which is related to the process

If the positive current that transmits the polar knot through the basis VBE the basis of the basal emission pole voltage

]

In the active area, -1 items can be ignored, may be eliminated, obtained the following formula

In the above equation, η and IS depend on the manufacture of manufacturing The process diode of special materials. Very controllableThe ratio (n) is applied to two currents and the voltage difference generated by measuring is possible to eliminate the IS term. The relationship between the difference between the positive voltage:

The voltage of LM95221 also includes ifrs

The voltage drop of the series resistance. Non -ideal,, is the only parameter that is not considered depends on the diode used to measure. Because #8710; VBE is proportional to η and T, the change of η cannot be distinguished from the temperature change. Because non -ideal factors are not controlled by temperature sensors, it will directly increase the sensor. The change of the Pentium 4 and the mobile Pentium processor -m Intel changes between the components to ± 0.1%. As a, for example, assuming that the temperature sensor has accuracy of ± 1 ± 1 ± 1 ± 1 ; C and the process for manufacturing diode at 25 ° C, and the process for manufacturing diode had irrational imaginative changes ± 0.1%. The final accuracy of the temperature sensor at room temperature is: TACC ± 1 ; C+(298 ; K) ± 1.4 ; C The additional error in the temperature measurement of the temperature of the temperature Calculate the remote control diode.

Application Tips (continued)

Non -ideal compensation of diode

In order to compensate the error caused by non -idealism, the temperature sensor Special calibration processor was performed. The national semiconductor temperature sensor has always been calibrated to the typical non -ideal state of a given processor type. LM95221 calibration is the series resistance of non -ideal 1.008 and 2.7 . When the temperature calibrated by a specific processor type, the sensor and different processor types or a given processor type have introduced typical non -ideal errors. Temperature errors related to non -idealism can be calibrated through the use of software.

In noisy environments, such as processor motherboards, the layout consideration is critical. The noise induction turns on the trajectory between the remote temperature diode sensor and the LM95221 can cause temperature conversion errors. Remember that the signal level of LM95221 is to try to measure slightly. The following guide shall follow:

1.vdd should use a 0.1 μF capacitor (100 PF) parallel. 100PF capacitors should be placed as close to the power as possible. A large capacitor is about 10 μF near LM95221.

2. Need a 2.2NF diode bypass electrical container to filter high -electric flat frequency noise. The 2.2NF capacitor is as close to the D+and D-pins that can be used as LM95221. Make sure that the 2.2NF capacitor is matched.

3. Ideally, the trajectory of LM95221 should be placed in the processor diode pipe pin, short, as short as possible. 1 trace wire resistance can cause errors of up to 1 ; c. This error can be simpleSoftware compensation compensation compensation.

4. The diode trajectory shall be surrounded by the ground protection ring, which may be surrounded by the ground. This GND protective cover should not be between D+and D-wires. If the noise is really coupled to the diode line, if it is a coupling co -mode, it is ideal. That is the same D+and D-wires.

5. Avoid providing switches or filter inductors at a diode near the power supply.

6. Avoid the high -speed digital and bus lines that are close to or parallel to high. The trace of the diode should be at least 2 cm from the high -speed digital record.

7. If you need to cross high -speed digital records, the diode trajectory and high -speed digital trajectory should cross at 90 degrees.

8. The ideal position of connecting the LM95221 GND pin is as close to the relevant processor GND induction diode as possible.

The leak current between the D the leak current between the D+D the minimum value. 13 mA's leakage can cause the diode temperature reading of up to 0.2 degrees Celsius. Keeping the printing circuit board as clean as possible will minimize the leakage current. The noise coupling to a digital line (typical lag) greater than 400mvp-P and an underwriting GND below 500MV may prevent SMBUS and LM95221. SMBUS is not responding to the most common symptoms, leading to unnecessary traffic on bus. Although SMBUS's maximum communication frequency is low (maximum 100kHz), you still need to carefully ensure that the correct terminal bus and long -printed circuit board traces of multiple components in the system are still needed. RC low -pass, including 3DB corner frequencies with a frequency of about 40MHz, at the SMBCLK input of LM95221. Additional resistance tanks and SMBDAT and SMBCLK are connected in series to further help filtering noise and ringtone. To minimize noise coupling to exclude digital lines outside the switching power supply area and ensure that the digital line contains high -speed data communication and SMBDAT into right -angle crossing and SMBCLK lines.