TMP12 Analog Devices, TMP12 Datasheet
TMP12
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TMP12 Summary of contents
Page 1
... LOW GND above ambient (in still air). The purpose of the heater in the TMP12 is to emulate a power IC, such as a regulator or Pentium CPU, which has a high internal dissipation. When subjected to a fast airflow, the package and die tempera- tures of the power device and the TMP12 (if located in the same airstream) will be reduced by an amount proportional to the rate of airflow ...
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... Supply Current NOTES 1 Guaranteed but not tested. 2 TMP12 is specified for operation from supply. However, operation is allowed supply, but not tested Maximum heater supply Specifications subject to change without notice –40 C ≤ ≤ 125 C, unless otherwise noted.) (V ...
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... The heat source for the TMP12 is an on-chip 100 Ω low tempco thin-film resistor. When connected source, this resistor dissipates which generates a temperature rise of about 32°C in still air for the SOIC packaged device. With an airflow of 450 feet per minute (FPM), the temperature rise is about 22° ...
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... TMP12 –Typical Performance Characteristics SOIC-8 SOLDERED TO 30 0.5 0.3 CU PCB 25 250 FPM 20 0 FPM 15 450 FPM 10 600 FPM 5 AIR FLOW RATES 100 150 200 250 HEATER RESISTOR POWER DISSIPATION (mW) TPC 1. SOIC Junction Temperature Rise vs. Heater Dissipation 120 TRANSITION FROM STILL 25 C 110 ...
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... SUPPLY VOLTAGE (V) TPC 10. Supply Current vs. Supply Voltage APPLICATIONS INFORMATION A typical application for the TMP12 is shown in Figure 2. The TMP12 package is placed in the same cooling airflow as a high power dissipation IC. The TMP12’s internal resistor produces a temperature rise that is proportional to air flow, as shown in Figure 3 ...
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... TMP12 Figure 4 shows the TMP12’s hysteresis profile. The hysteresis is programmed by the user by setting a specific load current on the reference voltage output This output current, I REF called the hysteresis current mirrored internally by the REF TMP12, as shown in the Functional Block Diagram, and is fed to a buffer with an analog switch ...
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... VPTAT voltage. A simple method of measuring the TMP12 VPTAT is shown in Figure 7. To measure VPTAT, adjust potentiometer R1 until the LED turns on. The voltage at Pin 2 of the TMP12 will then match the TMP12’s internal VPTAT. VPTAT ...
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... TMP12. For Setpoint 2, self-heating will add to the Setpoint temperature (that is, in the above example, the TMP12 will switch the Setpoint 2 output off 1.9°C early). Self-heating will not affect the tempera- ture at which Setpoint 1 turns on, but will add to the hysteresis. ...
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... TPCs 2 and 4 illustrate the typical RC time constant response to a step change in ambient temperature. Thus, the time required for the TMP12 to settle to the desired accuracy is dependent on the package selected, the thermal contact established in the particular application, and the equivalent thermal conductiv- ity of the heat source ...
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... Q2 on, pulling its collector low. Thus, the output taken from the collector identical to the output of the TMP12. By picking a transis- tor that can accommodate large amounts of current, many high-power devices can be switched. ...
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... Figure 15. An External Transistor Minimizes Self-Heating TEMPERATURE V REF HYSTERESIS GENERATOR TMP12 Figure 17. Darlington Transistor Can Handle Large Currents REV 4.7k 2N1711 Q1 Figure 16. Second Transistor Maintains Polarity of TMP12 Output 12V VPTAT V+ SENSOR AND 8 VOLTAGE TIP-110 4.7k 4.7k REFERENCE 2N1711 7 WINDOW COMPARATOR 100 – ...
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... TMP12 0.25 (0.0098) 0.10 (0.0040) COPLANARITY CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN Revision History Location 12/03—Data Sheet changed from REV REV. B. Edits to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Edits to TYPICAL PERFORMANCE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Updated OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 09/01— ...