ADT7461AARMZ-2 ON Semiconductor, ADT7461AARMZ-2 Datasheet
ADT7461AARMZ-2
Specifications of ADT7461AARMZ-2
Available stocks
Related parts for ADT7461AARMZ-2
ADT7461AARMZ-2 Summary of contents
Page 1
... SMBus address of 0x4D. This is useful if more than one ADT7461A is used on the same SMBus. An ALERT output signals when the on−chip or remote temperature is out of range. The THERM output is a comparator output that allows on/off control of a cooling fan. The ALERT output can be reconfigured as a second THERM output, if required ...
Page 2
... SCLK, SDATA, ALERT, THERM Input Current, SDATA, THERM Input Current, D− ESD Rating, All Pins (Human Body Model) Maximum Junction Temperature (T Max) J Storage Temperature Range Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied ...
Page 3
... PIN ASSIGNMENT Pin No. Mnemonic 1 V Positive Supply Positive Connection to Remote Temperature Sensor. 3 D− Negative Connection to Remote Temperature Sensor. 4 THERM Open−Drain Output. Can be used to turn a fan on/off or throttle a CPU clock in the event of an overtemperature condition. Requires pullup resistor. 5 GND Supply Ground Connection ...
Page 4
... Parameter Power Supply Supply Voltage Average Operating Supply Current Undervoltage Lockout Threshold Power−On−Reset Threshold Temperature−To−Digital Converter Local Sensor Accuracy Resolution Remote Diode Sensor Accuracy Resolution Remote Sensor Source Current Conversion Time Maximum Series Resistance Cancelled Open−Drain Digital Outputs (THERM, ALERT/THERM2) ...
Page 5
... Figure 4. Remote Temperature Error vs. Actual 0 –2 –4 –6 –8 –10 –12 –14 –16 –18 0 100 Figure 6. Temperature Error vs. D+/D− Capacitance 422 DEV 2BC 420 418 416 414 412 410 408 10 100 3.0 Figure 8. Operating Supply Current vs. Voltage http://onsemi.com ...
Page 6
... NOISE FREQUENCY (MHz) Figure 11. Temperature Error vs. Common−Mode Noise Frequency Figure 13. Temperature Error vs. Series Resistance TYPICAL CHARACTERISTICS 35 DEV 2BC DEV 2 DEV 3BC 30 DEV 4BC 25 DEV 3.5 3.6 1 Figure 10. Standby Supply Current vs. Clock 80 70 ...
Page 7
... The ADC digitizes these signals and the results are stored in the local and remote temperature value registers. The local and remote measurement results are compared with the corresponding high, low, and THERM temperature limits, stored in eight on− ...
Page 8
... 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 ...
Page 9
... THERM2 output. Bit 7, the ALERT mask bit, is only active when Pin 6 is configured as an ALERT output. If Pin 6 is set THERM2 output, then Bit 7 has no effect. Bit 2 sets the temperature measurement range. If Bit (default value), the temperature measurement range is set between 0°C to +127°C. Setting Bit sets the measurement range to the extended temperature range (− ...
Page 10
... Register 0x21. The THERM output is reset only when the temperature falls to limit value minus the hysteresis value. When Pin 6 is configured as THERM2, only the high temperature limits are relevant. If Flag 6 and/or Flag 4 are set, the THERM2 output goes low to indicate that the temperature measurements are outside the programmed limits ...
Page 11
... ADT7461A to perform a conversion and comparison on both the internal and the external temperature channels. This is not a data register as such, and it is the write operation to Address 0x0F that causes the one−shot conversion. The data written to this address is irrelevant and is not stored ...
Page 12
... External Temperature Low Limit High Byte One−Shot External Temperature Value Low Byte External Temperature Offset High Byte External Temperature Offset Low Byte External Temperature High Limit Low Byte External Temperature Low Limit Low Byte External THERM Limit Local THERM Limit THERM Hysteresis ...
Page 13
When all data bytes have been read or written, stop conditions are established. In write ...
Page 14
... It does not matter what is written to the one−shot register, all data written ignored also possible to write new values to the limit register while in standby mode. If the values stored in the temperature value registers are outside the new limits, an ALERT is generated, even though the ADT7461A is still in standby. ...
Page 15
... Figure 19 shows how the THERM and ALERT outputs operate. The ALERT output can be used as a SMBALERT to signal to the host via the SMBus that the temperature has risen. The user can use the THERM output to turn on a fan to cool the system, if the temperature continues to increase. ...
Page 16
... The ADT7461A is trimmed for an nF value of 1.008. The following equation may be used to calculate the error introduced at a temperature, T (°C), when using a transistor whose nF does not equal 1.008. Consult the processor data sheet for the nF values. ...
Page 17
... not, the thermal inertia caused by the sensor’s mass causes a lag in the response of the sensor to a temperature change. In the case of the remote sensor, this should not be a problem since it is either a substrate transistor in the processor or a small package device, such as the SOT−23, placed in close proximity to it. The on− ...
Page 18
... ADT7461AARMZ−R ADT7461AARMZ−RL7 8−Lead MSOP ADT7461AARMZ−002 ADT7461AARMZ−2RL ADT7461AARMZ2RL7 †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. *The “Z’’ suffix indicates Pb−Free package available. ...
Page 19
... A1 8X *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. Protected by U.S. Patents 5,195,827; 5,867,012; 5,982,221; 6,097,239; 6,133,753; 6,169,442; 7,010,440 ; other patents pending. ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein ...