TMP03GBC

a FEATURES Low Cost 3-Pin Package Modulated Serial Digital Output Proportional to Temperature ± 1.5 C Accuracy (typ) from –25 C to +100 C Specified –40 C to +100 C, Operation to 150 C Power Consumption 6.5 mW Max at 5 V Flexible Open-Collector Output on TMP03 CMOS/TTL Compatible Output on TMP04 Low Voltage Operation (4.5 V to 7 V) APPLICATIONS Isolated Sensors Environmental Control Systems Computer Thermal Monitoring Thermal Protection Industrial Process Control Power System Monitors Serial Digital Output Thermometers TMP03/TMP04* FUNCTIONAL BLOCK DIAGRAM TMP03/04 TEMPERATURE SENSOR VPTAT DIGITAL MODULATOR VREF 1 DOUT 2 V+ 3 GND PACKAGE TYPES AVAILABLE TO-92 GENERAL DESCRIPTION The TMP03/TMP04 is a monolithic temperature detector that generates a modulated serial digital output that varies in direct proportion to the temperature of the device. An onboard sensor generates a voltage precisely proportional to absolute temperature which is compared to an internal voltage reference and input to a precision digital modulator. The ratiometric encoding format of the serial digital output is independent of the clock drift errors common to most serial modulation techniques such as voltageto-frequency converters. Overall accuracy is ± 1.5°C (typical) from –25°C to +100°C, with excellent transducer linearity. The digital output of the TMP04 is CMOS/TTL compatible, and is easily interfaced to the serial inputs of most popular microprocessors. The open-collector output of the TMP03 is capable of sinking 5 mA. The TMP03 is best suited for systems requiring isolated circuits utilizing optocouplers or isolation transformers. The TMP03 and TMP04 are specified for operation at supply voltages from 4.5 V to 7 V. Operating from +5 V, supply current (unloaded) is less than 1.3 mA. The TMP03/TMP04 are rated for operation over the –40°C to +100°C temperature range in the low cost TO-92, SO-8, and TSSOP-8 surface mount packages. Operation extends to +150°C with reduced accuracy. (continued on page 4) *Patent pending. TMP03/04 1 DOUT 2 V+ 3 GND BOTTOM VIEW (Not to Scale) SO-8 and RU-8 (TSSOP) DOUT 1 V+ 2 GND 3 8 NC TMP03/04 7 NC TOP VIEW 6 NC (Not to Scale) NC 4 5 NC NC = NO CONNECT REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. © Analog Devices, Inc., 1995 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 617/329-4700 Fax: 617/326-8703 TMP03/TMP04–SPECIFICATIONS TMP03F (V+ = +5 V, –40 C ≤ T ≤ 100 C unless otherwise noted) A Parameter ACCURACY Temperature Error Temperature Linearity Long-Term Stability Nominal Mark-Space Ratio Nominal T1 Pulse Width Power Supply Rejection Ratio OUTPUTS Output Low Voltage Output Low Voltage Output Low Voltage Digital Output Capacitance Fall Time Device Turn-On Time POWER SUPPLY Supply Range Supply Current Symbol Conditions TA = +25°C –25°C < TA < +100°C1 –40°C < TA < –25°C1 Min Typ 1.0 1.5 2.0 0.5 0.5 58.8 10 0.7 Max 3.0 4.0 5.0 Units °C °C °C °C °C % ms °C/V T1/T2 T1 PSRR 1000 Hours at +125°C T A = 0° C Over Rated Supply TA = +25°C ISINK = 1.6 mA ISINK = 5 mA 0°C < TA < +100°C ISINK = 4 mA –40°C < TA < 0°C (Note 2) See Test Load 1.2 VOL VOL VOL COUT tHL 0.2 2 2 15 150 20 4.5 7 1.3 V V V pF ns ms V mA V+ ISY Unloaded 0.9 NOTES 1 Maximum deviation from output transfer function over specified temperature range. 2 Guaranteed but not tested. Specifications subject to change without notice. Test Load 10 kΩ to +5 V Supply, 100 pF to Ground TMP04F (V+ = +5 V, –40 C ≤ T ≤ +100 C unless otherwise noted) A Parameter ACCURACY Temperature Error Temperature Linearity Long-Term Stability Nominal Mark-Space Ratio Nominal T1 Pulse Width Power Supply Rejection Ratio OUTPUTS Output High Voltage Output Low Voltage Digital Output Capacitance Fall Time Rise Time Device Turn-On Time POWER SUPPLY Supply Range Supply Current Symbol Conditions TA = +25°C –25°C < TA < +100°C1 –40°C < TA < –25°C1 Min Typ 1.0 1.5 2.0 0.5 0.5 58.8 10 0.7 Max 3.0 4.0 5.0 Units °C °C °C °C °C % ms °C/V T1/T2 T1 PSRR 1000 Hours at +125°C T A = 0° C Over Rated Supply TA = +25°C IOH = 800 µA IOL = 800 µA (Note 2) See Test Load See Test Load V+ –0.4 1.2 VOH VOL COUT tHL tLH 0.4 15 200 160 20 4.5 7 1.3 V V pF ns ns ms V mA V+ ISY Unloaded 0.9 NOTES 1 Maximum deviation from output transfer function over specified temperature range. 2 Guaranteed but not tested. Specifications subject to change without notice. Test Load 100 pF to Ground –2– REV. 0 TMP03/TMP04 WAFER TEST LIMITS (V+ = +5 V, GND = 0 V, T = +25 C, unless otherwise noted) A Parameter ACCURACY Temperature Error Power Supply Rejection Ratio OUTPUTS Output High Voltage, TMP04 Output Low Voltage, TMP04 Output Low Voltage, TMP03 POWER SUPPLY Supply Range Supply Current Symbol Conditions TA = +25°C1 Over Rated Supply IOH = 800 µA IOL = 800 µA ISINK = 1.6 mA Min Typ Max 3.0 1.2 Units °C °C/V V V V V mA PSRR VOH VOL VOL V+ ISY V+ – 0.4 0.4 0.2 4.5 7 1.3 Unloaded NOTES Electrical tests are performed at wafer probe to the limits shown. Due to variations in assembly methods and normal yield loss, yield after packaging is not guaranteed for standard product dice. Consult factory to negotiate specifications based on dice lot qualification through sample lot assembly and testing. 1 Maximum deviation from ratiometric output transfer function over specified temperature range. ABSOLUTE MAXIMUM RATINGS* DICE CHARACTERISTICS Maximum Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . +9 V Maximum Output Current (TMP03 DOUT) . . . . . . . . . 50 mA Maximum Output Current (TMP04 DOUT) . . . . . . . . . 10 mA Maximum Open-Collector Output Voltage (TMP03) . . +18 V Operating Temperature Range . . . . . . . . . . . –55°C to +150°C Dice Junction Temperature . . . . . . . . . . . . . . . . . . . . +175°C Storage Temperature Range . . . . . . . . . . . . –65°C to +160°C Lead Temperature (Soldering, 60 sec) . . . . . . . . . . . . +300°C *CAUTION 1 Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation at or above this specification is not implied. Exposure to the above maximum rating conditions for extended periods may affect device reliability. 2 Digital inputs and outputs are protected, however, permanent damage may occur on unprotected units from high-energy electrostatic fields. Keep units in conductive foam or packaging at all times until ready to use. Use proper antistatic handling procedures. 3 Remove power before inserting or removing units from their sockets. Die Size 0.050 × 0.060 inch, 3,000 sq. mils ( 1.27 × 1.52 mm, 1.93 sq. mm) For additional DICE ordering information, refer to databook. Package Type TO-92 (T9) SO-8 (S) TSSOP (RU) ΘJA 1621 1581 2401 ΘJC 120 43 43 Units °C/W °C/W °C/W ORDERING GUIDE NOTE 1 ΘJA is specified for device in socket (worst case conditions). Model TMP03FT9 TMP03FS TMP03FRU TMP03GBC TMP04FT9 TMP04FS TMP04FRU TMP04GBC Accuracy at +25 C ± 3.0 ± 3.0 ± 3.0 ± 3.0 ± 3.0 ± 3.0 ± 3.0 ± 3.0 Temperature Range XIND XIND XIND +25°C XIND XIND XIND +25°C Package TO-92 SO-8 TSSOP-8 Die TO-92 SO-8 TSSOP-8 Die CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the TMP03/TMP04 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. WARNING! ESD SENSITIVE DEVICE REV. 0 –3– TMP03/TMP04 (continued from page 1) The TMP03/TMP04 is a powerful, complete temperature measurement system with digital output, on a single chip. The onboard temperature sensor follows in the footsteps of the TMP01 low power programmable temperature controller, offering excellent accuracy and linearity over the entire rated temperature range without correction or calibration by the user. The sensor output is digitized by a first-order sigma-delta modulator, also known as the “charge balance” type analog-todigital converter. (See Figure 1.) This type of converter utilizes time-domain oversampling and a high accuracy comparator to deliver 12 bits of effective accuracy in an extremely compact circuit. ∑∆ MODULATOR INTEGRATOR COMPARATOR VOLTAGE REF & VPTAT neatly avoids major error sources common to other modulation techniques, as it is clock-independent. Output Encoding ∫ 1-BIT DAC Accurate sampling of an analog signal requires precise spacing of the sampling interval in order to maintain an accurate representation of the signal in the time domain. This dictates a master clock between the digitizer and the signal processor. In the case of compact, cost-effective data acquisition systems, the addition of a buffered, high speed clock line can represent a significant burden on the overall system design. Alternatively, the addition of an onboard clock circuit with the appropriate accuracy and drift performance to an integrated circuit can add significant cost. The modulation and encoding techniques utilized in the TMP03/TMP04 avoid this problem and allow the overall circuit to fit into a compact, three-pin package. To achieve this, a simple, compact onboard clock and an oversampling digitizer that is insensitive to sampling rate variations are used. Most importantly, the digitized signal is encoded into a ratiometric format in which the exact frequency of the TMP03/TMP04’s clock is irrelevant, and the effects of clock variations are effectively canceled upon decoding by the digital filter. The output of the TMP03/TMP04 is a square wave with a nominal frequency of 35 Hz (± 20%) at +25°C. The output format is readily decoded by the user as follows: T1 T2 CLOCK GENERATOR DIGITAL FILTER TMP03/04 OUT (SINGLE-BIT) Figure 1. TMP03/TMP04 Block Diagram Showing First-Order Sigma-Delta Modulator Basically, the sigma-delta modulator consists of an input sampler, a summing network, an integrator, a comparator, and a 1-bit DAC. Similar to the voltage-to-frequency converter, this architecture creates in effect a negative feedback loop whose intent is to minimize the integrator output by changing the duty cycle of the comparator output in response to input voltage changes. The comparator samples the output of the integrator at a much higher rate than the input sampling frequency, called oversampling. This spreads the quantization noise over a much wider band than that of the input signal, improving overall noise performance and increasing accuracy. The modulated output of the comparator is encoded using a circuit technique (patent pending) which results in a serial digital signal with a mark-space ratio format that is easily decoded by any microprocessor into either degrees centigrade or degrees Fahrenheit values, and readily transmitted or modulated over a single wire. Most importantly, this encoding method Figure 2. TMP03/TMP04 Output Format  400 × T 1  Temperature (°C) = 235 −   T2   720 × T 1  Temperature (°F) = 455 −   T2  The time periods T1 (high period) and T2 (low period) are values easily read by a microprocessor timer/counter port, with the above calculations performed in software. Since both periods are obtained consecutively, using the same clock, performing the division indicated in the above formulas results in a ratiometric value that is independent of the exact frequency of, or drift in, either the originating clock of the TMP03/TMP04 or the user’s counting clock. –4– REV. 0 TMP03/TMP04 Table I. Counter Size and Clock Frequency Effects on Quantization Error Maximum Count Available 4096 8192 16384 Optimizing Counter Characteristics Maximum Temp Required +125°C +125°C +125°C Maximum Frequency 94 kHz 188 kHz 376 kHz Quantization Error (+25 C) 0.284°C 0.142°C 0.071°C Quantization Error (+77 F) 0.512°F 0.256°F 0.128°F Counter resolution, clock rate, and the resultant temperature decode error that occurs using a counter scheme may be determined from the following calculations: 1. T1 is nominally 10 ms, and compared to T2 is relatively insensitive to temperature changes. A useful worst-case assumption is that T1 will never exceed 12 ms over the specified temperature range. T1 max = 12 ms Substituting this value for T1 in the formula, temperature (°C) = 235 – ([T1/T2] × 400), yields a maximum value of T2 of 44 ms at 125°C. Rearranging the formula allows the maximum value of T2 to be calculated at any maximum operating temperature: T2 (Temp) = (T1max × 400)/(235 – Temp) in seconds 2. We now need to calculate the maximum clock frequency we can apply to the gated counter so it will not overflow during T2 time measurement. The maximum frequency is calculated using: Frequency (max) = Counter Size/ (T2 at maximum temperature) Substituting in the equation using a 12-bit counter gives, Fmax = 4096/44 ms 94 kHz. 3. Now we can calculate the temperature resolution, or quantization error, provided by the counter at the chosen clock frequency and temperature of interest. Again, using a 12-bit counter being clocked at 90 kHz (to allow for ~5% temperature over-range), the temperature resolution at +25°C is calculated from: Quantization Error (°C) = 400 × ([Count1/Count2] – [Count1 – 1]/[Count2 + 1]) Quantization Error (°F) = 720 × ([Count1/Count2] – [Count1 – 1]/[Count2 + 1]) where, Count1 = T1max × Frequency, and Count2 = T2 (Temp) × Frequency. At +25°C this gives a resolution of better than 0.3°C. Note that the temperature resolution calculated from these equations improves as temperature increases. Higher temperature resolution will be obtained by employing larger counters as shown in Table I. The internal quantization error of the TMP03/TMP04 sets a theoretical minimum resolution of approximately 0.1°C at +25°C. Self-Heating Effects typically 4.5 mW operating at 5 V with no load. In the TO-92 package mounted in free air, this accounts for a temperature increase due to self-heating of ∆T = PDISS × ΘJA = 4.5 mW × 162°C/W = 0.73°C (1.3°F) For a free-standing surface-mount TSSOP package, the temperature increase due to self-heating would be ∆T = PDISS × ΘJA = 4.5 mW × 240°C/W = 1.08°C (1.9°F) In addition, power is dissipated by the digital output which is capable of sinking 800 µA continuous (TMP04). Under full load, the output may dissipate  T2  P DISS = (0.6 V )(0.8 mA)   T1 + T 2  For example with T2 = 20 ms and T1 = 10 ms, the power dissipation due to the digital output is approximately 0.32 mW with a 0.8 mA load. In a free-standing TSSOP package this accounts for a temperature increase due to output self-heating of ∆T = PDISS × ΘJA = 0.32 mW × 240°C/W = 0.08°C (0.14°F) This temperature increase adds directly to that from the quiescent dissipation and affects the accuracy of the TMP03/ TMP04 relative to the true ambient temperature. Alternatively, when the same package has been bonded to a large plate or other thermal mass (effectively a large heatsink) to measure its temperature, the total self-heating error would be reduced to approximately ∆T = PDISS × ΘJC = (4.5 mW + 0.32 mW) × 43°C/W = 0.21°C (0.37°F) Calibration The TMP03 and TMP04 are laser-trimmed for accuracy and linearity during manufacture and, in most cases, no further adjustments are required. However, some improvement in performance can be gained by additional system calibration. To perform a single-point calibration at room temperature, measure the TMP03/TMP04 output, record the actual measurement temperature, and modify the offset constant (normally 235; see the Output Encoding section) as follows: Offset Constant = 235 + (TOBSERVED – TTMP03OUTPUT) A more complicated two-point calibration is also possible. This involves measuring the TMP03/TMP04 output at two temperatures, Temp1 and Temp2, and modifying the slope constant (normally 400) as follows: The temperature measurement accuracy of the TMP03/TMP04 may be degraded in some applications due to self-heating. Errors introduced are from the quiescent dissipation, and power dissipated by the digital output. The magnitude of these temperature errors is dependent on the thermal conductivity of the TMP03/TMP04 package, the mounting technique, and effects of airflow. Static dissipation in the TMP03/TMP04 is REV. 0 –5– Slope Constant = Temp 2 − Temp 1  T 1 @ Temp 1   T 1 @ Temp 2    −   T 2 @ Temp 1  T 2 @ Temp 2  where T1 and T2 are the output high and output low times, respectively. TMP03/TMP04–Typical Performance Characteristics 70 60 V+ = +5V RLOAD = 10kΩ 1.05 1.04 1.03 1.02 1.01 1.00 0.99 0.98 0.97 4.5 TA = +25°C RLOAD = 10kΩ NORMALIZED OUTPUT FREQUENCY OUTPUT FREQUENCY – Hz 50 40 30 20 10 0 –75 –25 25 75 TEMPERATURE – °C 125 175 5 5.5 6 6.5 SUPPLY VOLTAGE – Volts 7 7.5 Figure 3. Output Frequency vs. Temperature 45 40 35 30 VS = +5V RLOAD = 10kΩ Figure 6. Normalized Output Frequency vs. Supply Voltage Running: 50.0MS/s Sample (T) Ch 1 +Width ∞s Wfm does not cross ref Ch 1 –Width ∞s Wfm does not cross ref T2 VOLTAGE SCALE = 2V/DIV TA = +25°C VDD = +5V TIME – ms 25 20 15 T1 10 5 CLOAD = 100pF RLOAD = 1kΩ Ch 1 Rise 500ns Ch 1 Fall ∞s No valid edge TIME SCALE = 1µs/DIV 0 –75 –25 25 75 TEMPERATURE – °C 125 175 Figure 4. T1 and T2 Times vs. Temperature Figure 7. TMP03 Output Rise Time at +25 °C Running: 200MS/s ET Sample (T) Running: 50.0MS/s Sample (T) Ch 1 +Width ∞s Wfm does not cross ref Ch 1 –Width ∞s Wfm does not cross ref VOLTAGE SCALE = 2V/DIV VOLTAGE SCALE – 2V/DIV TA = +25°C VDD = +5V Ch 1 +Width ∞s Wfm does not cross ref Ch 1 –Width ∞s Wfm does not cross ref TA = +125°C VDD = +5V CLOAD = 100pF RLOAD = 1kΩ Ch 1 Rise ∞s No valid edge Ch 1 Fall 209.6ns CLOAD = 100pF RLOAD = 1kΩ Ch 1 Rise 538ns Ch 1 Fall ∞s No valid edge TIME SCALE = 250ns/DIV TIME SCALE – 1µs/DIV Figure 5. TMP03 Output Fall Time at +25 °C Figure 8. TMP03 Output Rise Time at +125 °C –6– REV. 0 TMP03/TMP04 Running: 200MS/s ET Sample (T) Ch 1 +Width ∞s Wfm does not cross ref Ch 1 –Width ∞s Wfm does not cross ref Ch 1 Rise ∞s No valid edge Ch 1 Fall 139.5ns Edge Slope Running: 200MS/s ET Sample (T) Ch 1 +Width ∞s Wfm does not cross ref Ch 1 –Width ∞s Wfm does not cross ref VOLTAGE SCALE = 2V/DIV VOLTAGE SCALE – 2V/DIV TA = +25°C VDD = +5V TA = +125°C VDD = +5V CLOAD = 100pF RLOAD = 1kΩ CLOAD = 100pF RLOAD = 0 Ch 1 Rise 110.6ns Ch 1 Fall ∞s No valid edge TIME SCALE = 250ns/DIV TIME SCALE – 250ns/DIV Figure 9. TMP03 Output Fall Time at +125 °C Figure 12. TMP04 Output Rise Time at +25 °C Running: 200MS/s ET Sample (T) Running: 200MS/s ET Sample (T) Ch 1 +Width ∞s Wfm does not cross ref Ch 1 –Width ∞s Wfm does not cross ref VOLTAGE SCALE = 2V/DIV VOLTAGE SCALE – 2V/DIV TA = +25°C VDD = +5V Ch 1 +Width ∞s Wfm does not cross ref Ch 1 –Width ∞s Wfm does not cross ref Ch 1 Rise ∞s No valid edge Ch 1 Fall 127.6ns TA = +125°C VDD = +5V CLOAD = 100pF RLOAD = 0 Ch 1 Rise 149.6ns Ch 1 Fall ∞s No valid edge CLOAD = 100pF RLOAD = 0 TIME SCALE = 250ns/DIV TIME SCALE – 250ns/DIV Figure 10. TMP04 Output Fall Time at +25 °C Figure 13. TMP04 Output Rise Time at +125 °C 2500 Running: 200MS/s ET Sample (T) VOLTAGE SCALE = 2V/DIV TA = +125°C VDD = +5V Ch 1 +Width ∞s Wfm does not cross ref 2000 TA = +25°C VS = +5V RLOAD = ∞ FALL TIME CLOAD = 100pF RLOAD = 0 Ch 1 Rise ∞s No valid edge Ch 1 Fall 188.0ns TIME – ns Ch 1 –Width ∞s Wfm does not cross ref 1500 1000 RISE TIME 500 TIME SCALE = 250ns/DIV 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 LOAD CAPACITANCE – pF Figure 11. TMP04 Output Fall Time at +125 °C Figure 14. TMP04 Output Rise & Fall Times vs. Capacitive Load REV. 0 –7– TMP03/TMP04 5 4 3 OUTPUT ACCURACY – °C 2 1 TMP03 0 –1 –2 –3 –4 –5 –50 –25 0 MINIMUM LIMIT TMP04 V+ = +5V RLOAD = 10kΩ MEASUREMENTS IN STIRRED OIL BATH MAXIMUM LIMIT 5 START-UP VOLTAGE DEFINED AS OUTPUT READING BEING WITHIN ±5°C OF OUTPUT AT +4.5V SUPPLY 4.5 START-UP SUPPLY VOLTAGE – Volts RLOAD = 10kΩ 4 3.5 25 50 75 TEMPERATURE – °C 100 125 3 –75 –25 25 75 TEMPERATURE – °C 125 175 Figure 15. Output Accuracy vs. Temperature Figure 18. Start-Up Voltage vs. Temperature 1600 TYPICAL VALUES V+ = +5V RLOAD = 10kΩ 0, T2 OUTPUT STARTS LOW 0, T1 OUTPUT STARTS HIGH V+ 0 10 20 30 40 50 60 TIME – ms 70 80 90 100 T2 T1 T1 TEMP °C –55 +25 +125 T2 T2 ms 15 20 35 T1 ms SUPPLY CURRENT – µA 1400 1200 1000 800 600 400 200 0 TA = +25°C NO LOAD 10 10 10 0 1 2 3 4 5 6 SUPPLY VOLTAGE – Volts 7 8 Figure 16. Start-Up Response Figure 19. Supply Current vs. Supply Voltage 1100 1050 SUPPLY CURRENT – µA 1000 V+ = +5V NO LOAD 4 3.5 3 2.5 2 1.5 1 0.5 0 –75 V+ = 4.5 - 7V RLOAD = 10kΩ 950 900 TMP03 850 TMP04 800 750 –75 –25 25 75 TEMPERATURE – °C 125 175 POWER SUPPLY REJECTION – °C/V –25 25 75 TEMPERATURE – °C 125 175 Figure 17. Supply Current vs. Temperature Figure 20. Power Supply Rejection vs. Temperature –8– REV. 0 TMP03/TMP04 1 V+ = +5V dc ± 50mV ac RLOAD = 10kΩ 0.5 20 18 16 VOL = +1V V+ = +5V DEVIATION IN TEMPERATURE – °C SINK CURRENT – mA 14 12 10 8 6 4 NOMINAL PSRR 0 –0.5 –1 1 10 100 1k 10k 100k FREQUENCY – Hz 1M 10M 2 –75 –25 25 75 TEMPERATURE – °C 125 150 Figure 21. Power Supply Rejection vs. Frequency Figure 24. TMP03 Open-Collector Sink Current vs. Temperature 400 OPEN-COLLECTOR OUTPUT VOLTAGE – mV 350 V+ = +5V 300 ILOAD = 5mA 250 200 150 100 50 0 –75 ILOAD = 1mA ILOAD = 0.5mA –25 25 75 TEMPERATURE – *C 125 175 105 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 0 TRANSITION FROM +100°C STIRRED OIL BATH TO STILL +25°C AIR VS = +5V RLOAD = 10kΩ OUTPUT TEMPERATURE – °C τ ~ 23 sec (SOIC, NO SOCKET) τ ~ 40 sec (TO-92, NO SOCKET) TO-92 SOIC 25 50 75 100 125 150 175 200 225 250 275 300 TIME – sec Figure 22. TMP03 Open-Collector Output Voltage vs. Temperature Figure 25. Thermal Response Time in Still Air 140 120 TRANSITION FROM +100°C OIL BATH TO FORCED +25°C AIR 100 V+ = +5V RLOAD = 10kΩ SOIC OUTPUT TEMPERATURE – °C τ TIME CONSTANT – sec 100 TO-92 V+ = +5V RLOAD = 10kΩ 80 60 TO-92 – WITH SOCKET 40 TO-92 – NO SOCKET 20 0 SOIC – NO SOCKET τ≅ τ≅ 1.25 sec (SOIC IN SOCKET) 2 sec (TO-92 IN SOCKET) TRANSITION FROM STILL +25°C AIR TO STIRRED +100°C OIL BATH 25 0 100 200 300 400 500 AIR VELOCITY – FPM 600 700 0 10 20 30 TIME – sec 40 50 60 Figure 23. Thermal Time Constant in Forced Air Figure 26. Thermal Response Time in Stirred Oil Bath REV. 0 –9– TMP03/TMP04 APPLICATIONS INFORMATION Supply Bypassing TMP03/TMP04 Output Configurations Precision analog products, such as the TMP03/TMP04, require a well filtered power source. Since the TMP03/TMP04 operate from a single +5 V supply, it seems convenient to simply tap into the digital logic power supply. Unfortunately, the logic supply is often a switch-mode design, which generates noise in the 20 kHz to 1 MHz range. In addition, fast logic gates can generate glitches hundred of millivolts in amplitude due to wiring resistance and inductance. If possible, the TMP03/TMP04 should be powered directly from the system power supply. This arrangement, shown in Figure 27, will isolate the analog section from the logic switching transients. Even if a separate power supply trace is not available, however, generous supply bypassing will reduce supply-line induced errors. Local supply bypassing consisting of a 10 µF tantalum electrolytic in parallel with a 0.1 µF ceramic capacitor is recommended (Figure 28a). TTL/CMOS LOGIC CIRCUITS 10µF TANT 0.1µF The TMP03 (Figure 29a) has an open-collector NPN output which is suitable for driving a high current load, such as an opto-isolator. Since the output source current is set by the pullup resistor, output capacitance should be minimized in TMP03 applications. Otherwise, unequal rise and fall times will skew the pulse width and introduce measurement errors. The NPN transistor has a breakdown voltage of 18 V. V+ TMP03 DOUT TMP04 DOUT a. b. Figure 29. TMP03/TMP04 Digital Output Structure TMP03/ TMP04 +5V POWER SUPPLY The TMP04 has a “totem-pole” CMOS output (Figure 29b) and provides rail-to-rail output drive for logic interfaces. The rise and fall times of the TMP04 output are closely matched, so that errors caused by capacitive loading are minimized. If load capacitance is large, for example when driving a long cable, an external buffer may improve accuracy. See the “Remote Temperature Measurement” section of this data sheet for suggestions. Interfacing the TMP03 to Low Voltage Logic Figure 27. Use Separate Traces to Reduce Power Supply Noise +5V +5V 50Ω The TMP03’s open-collector output is ideal for driving logic gates that operate from low supply voltages, such as 3.3 V. As shown in Figure 30, a pull-up resistor is connected from the low voltage logic supply (2.9 V, 3 V, etc.) to the TMP03 output. Current through the pull-up resistor should be limited to about 1 mA, which will maintain an output LOW logic level of temperature result in 14.2 format 2 * TMP04 output period { Beginning TEMPERAT Program } { Entry point of this subroutine } } .MODULE/RAM/BOOT=0 TEMPERAT; .ENTRY TEMPMEAS; .CONST PRESCALER=4; .CONST TIMFULSCALE=0Xffff; TEMPMEAS: si=PRESCALER; sr0=TIMFULSCALE; dm(0x3FFB)=si; si=TIMFULSCALE; dm(0x3FFC)=si; dm(0x3FFD)=si; imask=0x01; TEST1: if not fi jump TEST1; TEST0: if fi jump TEST0; ena timer; COUNT2: if not fi jump COUNT2; dis timer; ay0=dm(0x3FFC); ar=sr0-ay0; ax0=ar; dm(0x3FFC)=si; ena timer; COUNT1: if fi jump COUNT1; dis timer; ay0=dm(0x3FFC); ar=sr0-ay0; my0=400; mr=ar*my0(uu); ay0=mr0; ar=mr1; af=pass ar; COMPUTE: astat=0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; divq ax0; ax0=0x03AC; ar=ax0-ay0; rts; .ENDMOD; For timer prescaler } Timer counter full scale } Timer Prescaler set up to 5 } CLKin=10MHz,Timer Period=32.768ms } Timer Counter Register to 65535 } Timer Period Register to 65535 } Unmask Interrupt timer } { Check for FI=1 } { Check for FI=0 to locate transition } { Enable timer, count at a 500ns rate } { Check for FI=1 to stop count } { Save counter=T2 in ALU register } { { { { { { { { Reload counter at full scale } { Check for FI=0 to stop count } { Save counter=T1 in ALU register } { { { { { { mr=400*T1 } af=MSW of dividend, ay0=LSW } ax0=16-bit divisor } To clear AQ flag } Division 400*T1/T2 } with 0.3 < T1/T2 < 0.7 } { { { { { Result in ay0 } ax0=235*4 } ar=235-400*T1/T2, result in øC } format 14.2 } End of the subprogram } –14– REV. 0 TMP03/TMP04 T1 DATA (MICROSECONDS) T2 DATA (MICROSECONDS) +5V 20 11 2 5 6 9 12 15 16 19 Q5 Q6 Q7 Q8 +5V 20 11 2 5 6 9 12 15 16 19 Q5 Q6 Q7 Q8 +5V 20 11 2 5 6 9 12 15 16 19 Q5 Q6 Q7 Q8 +5V 1 20 11 2 5 6 9 12 15 16 19 Q5 Q6 Q7 Q8 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 VCC LE 74HC373 OUT GND 1 10 VCC LE 74HC373 OUT GND 1 10 VCC LE 74HC373 OUT GND VCC 10 LE 74HC373 OUT GND 1 10 D1 D2 D3 D4 +5V 1 2 3 1 2 3 3 4 D5 D6 D7 D8 13 14 17 18 D1 D2 D3 D4 3 4 D5 D6 D7 D8 13 14 17 18 D1 D2 D3 D4 3 4 D5 D6 D7 D8 13 14 17 18 D1 D2 D3 D4 3 4 D5 D6 D7 D8 13 14 17 18 7 8 7 8 7 8 7 8 74HC08 4 5 6 +5V 16 2 3 VCC 4 5 6 10 11 12 13 14 +5V 3 4 5 6 10 11 12 13 14 Q0 Q1 Q2 Q3 EN Q0 Q1 Q2 Q3 16 Q0 Q1 Q2 Q3 EN Q0 Q1 Q2 Q3 VCC EN CLK 74HC4520 #1 CLK GND RESET RESET 2 74HC4520 #2 1MHZ CLOCK 1 EN CLK CLK GND RESET RESET 1 9 8 7 15 9 8 7 15 20pF 1kΩ 2 +5V 20pF 3.9kΩ +5V 14 74HC86 +5V 0.1µF 10µF 10kΩ 4 5 10pF 6 4 5 +5V A B 1 T1 15 3 CLR T2 16 VCC 6 Q 7 Q NC 12 11 13 T1 A B CLR T2 Q Q 10 9 NC GND 8 GND V+ DOUT 74HC4538 8 TMP04 GND Figure 36. A Hardware Interface for the TMP04 Monitoring Electronic Equipment The TMP03/TMP04 are ideal for monitoring the thermal environment within electronic equipment. For example, the surface mounted package will accurately reflect the exact thermal conditions which affect nearby integrated circuits. The TO-92 package, on the other hand, can be mounted above the surface of the board, to measure the temperature of the air flowing over the board. The TMP03 and TMP04 measure and convert the temperature at the surface of their own semiconductor chip. When the TMP03/TMP04 are used to measure the temperature of a nearby heat source, the thermal impedance between the heat source and the TMP03/TMP04 must be considered. Often, a thermocouple or other temperature sensor is used to measure the temperature of the source while the TMP03/TMP04 temperature is monitored by measuring T1 and T2. Once the thermal impedance is determined, the temperature of the heat source can be inferred from the TMP03/TMP04 output. One example of using the TMP04 to monitor a high power dissipation microprocessor or other IC is shown in Figure 37. The TMP04, in a surface mount package, is mounted directly beneath the microprocessor’s pin grid array (PGA) package. In a typical application, the TMP04’s output would be connected to an ASIC where the pulse width would be measured (see the Hardware Interface section of this data sheet for a typical REV. 0 –15– TMP03/TMP04 interface schematic). The TMP04 pulse output provides a significant advantage in this application because it produces a linear temperature output while needing only one I/O pin and without requiring an A/D converter. FAST MICROPROCESSOR, DSP, ETC., IN PGA PACKAGE Thermal Response Time PGA SOCKET TMP04 IN SURFACE MOUNT PACKAGE PC BOARD Figure 37. Monitoring the Temperature of a High Power Microprocessor Improves System Reliability The time required for a temperature sensor to settle to a specified accuracy is a function of the thermal mass of, and the thermal conductivity between, the sensor and the object being sensed. Thermal mass is often considered equivalent to capacitance. Thermal conductivity is commonly specified using the symbol Θ, and can be thought of as thermal resistance. It is commonly specified in units of degrees per watt of power transferred across the thermal joint. Thus, the time required for the TMP03/TMP04 to settle to the desired accuracy is dependent on the package selected, the thermal contact established in that particular application, and the equivalent power of the heat source. In most applications, the settling time is probably best determined empirically. The TMP03/TMP04 output operates at a nominal frequency of 35 Hz at +25°C, so the minimum settling time resolution is 27 ms. OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 3-Pin TO-92 0.135 (3.43) MIN 0.205 (5.20) 0.175 (4.96) 8-Pin SOIC (SO-8) 0.1968 (5.00) 0.1890 (4.80) 8 1 5 4 0.210 (5.33) 0.170 (4.38) SEATING PLANE 0.050 (1.27) MAX 0.1574 (4.00) 0.1497 (3.80) 0.2440 (6.20) 0.2284 (5.80) PIN 1 0.0098 (0.25) 0.0040 (0.10) 0.0688 (1.75) 0.0532 (1.35) 0.0196 (0.50) x 45° 0.0099 (0.25) 0.500 (12.70) MIN 0.019 (0.482) 0.016 (0.407) SQUARE SEATING PLANE 0.0500 0.0192 (0.49) (1.27) 0.0138 (0.35) BSC 0.0098 (0.25) 0.0075 (0.19) 8° 0° 0.0500 (1.27) 0.0160 (0.41) 0.105 (2.66) 0.095 (2.42) 0.105 (2.66) 0.080 (2.42) 0.055 (1.39) 0.045 (1.15) 8-Pin TSSOP (RU-8) 0.122 (3.10) 0.114 (2.90) 0.177 (4.50) 0.169 (4.30) 0.105 (2.66) 0.080 (2.42) 1 2 3 BOTTOM VIEW 1 4 PIN 1 0.006 (0.15) 0.002 (0.05) 0.0256 (0.65) BSC 0.256 (6.50) 0.246 (6.25) 0.165 (4.19) 0.125 (3.94) 8 5 SEATING PLANE 0.0118 (0.30) 0.0075 (0.19) 0.0079 (0.20) 0.0035 (0.090) 8° 0° 0.028 (0.70) 0.020 (0.50) –16– REV. 0 PRINTED IN U.S.A. 0.0433 (1.10) MAX C2063–18–9/95