TMP03 AD | Alldatasheet
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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. a Serial Digital Output Thermometers © Analog Devices, Inc., 1995 Tel: 617/329-4700 Fax: 617/326-8703
FEATURES
Modulated Serial Digital Output Proportional to Temperature ±1.58C Accuracy (typ) from –25 8C to +100 8C Specified –40 8C to +100 8C, Operation to 150 8C 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
Environmental Control Systems Computer Thermal Monitoring Thermal Protection Industrial Process Control Power System Monitors TMP03/TMP04* PACKAGE TYPES AVAILABLE TO-92 D OUT V+ GND 1 2 3 TMP03/04 BOTTOM VIEW (Not to Scale) SO-8 and RU-8 (TSSOP) TOP VIEW (Not to Scale) NC = NO CONNECT TMP03/04 D OUT NC NC NC NC GND NC 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 voltage- to-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 micro- processors. 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.
Parameter Symbol Conditions Min Typ Max Units ACCURACY Temperature Error T A = +25°C 1.0 3.0 °C Temperature Linearity 0.5 °C Long-Term Stability 1000 Hours at +125 °C 0.5 °C Nominal Mark-Space Ratio T1/T2 T A = 0°C 58.8 % Nominal T1 Pulse Width T1 10 ms Power Supply Rejection Ratio PSRR Over Rated Supply 0.7 1.2 °C/V TA = +25°C OUTPUTS Output Low Voltage V OL ISINK = 1.6 mA 0.2 V Output Low Voltage V OL ISINK = 5 mA 2 V 0°C < TA < +100°C Output Low Voltage V OL ISINK = 4 mA 2 V –40°C < TA < 0°C Digital Output Capacitance C OUT (Note 2) 15 pF Fall Time t HL See Test Load 150 ns Device Turn-On Time 20 ms POWER SUPPLY Supply Range V+ 4.5 7 V Supply Current I SY Unloaded 0.9 1.3 mA NOTES 1Maximum deviation from output transfer function over specified temperature range. 2Guaranteed but not tested. Specifications subject to change without notice. Test Load 10 kΩ to +5 V Supply, 100 pF to Ground TMP04F Parameter Symbol Conditions Min Typ Max Units ACCURACY Temperature Error T A = +25°C 1.0 3.0 °C Temperature Linearity 0.5 °C Long-Term Stability 1000 Hours at +125 °C 0.5 °C Nominal Mark-Space Ratio T1/T2 T A = 0°C 58.8 % Nominal T1 Pulse Width T1 10 ms Power Supply Rejection Ratio PSRR Over Rated Supply 0.7 1.2 °C/V TA = +25°C OUTPUTS Output High Voltage V OH IOH = 800 µA V+ –0.4 V Output Low Voltage V OL IOL = 800 µA 0.4 V Digital Output Capacitance C OUT (Note 2) 15 pF Fall Time t HL See Test Load 200 ns Rise Time t LH See Test Load 160 ns Device Turn-On Time 20 ms POWER SUPPLY Supply Range V+ 4.5 7 V Supply Current I SY Unloaded 0.9 1.3 mA NOTES 1Maximum deviation from output transfer function over specified temperature range. 2Guaranteed but not tested. Specifications subject to change without notice. Test Load 100 pF to Ground REV. 0 TMP03/TMP04–SPECIFICATIONS TMP03F(V+ = +5 V, –40 8C ≤ TA ≤ 1008C unless otherwise noted) (V+ = +5 V, –40 8C ≤ TA ≤ +1008C unless otherwise noted) –2–
REV. 0 –3– WAFER TEST LIMITS Parameter Symbol Conditions Min Typ Max Units ACCURACY Temperature Error T A = +25°C1 3.0 °C Power Supply Rejection Ratio PSRR Over Rated Supply 1.2 °C/V OUTPUTS Output High Voltage, TMP04 V OH IOH = 800 µA V+ – 0.4 V Output Low Voltage, TMP04 V OL IOL = 800 µA 0.4 V Output Low Voltage, TMP03 V OL ISINK = 1.6 mA 0.2 V POWER SUPPLY Supply Range V+ 4.5 7 V Supply Current I SY Unloaded 1.3 mA 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. 1Maximum deviation from ratiometric output transfer function over specified temperature range. (V+ = +5 V, GND = 0 V, T A = +258C, unless otherwise noted) WARNING! ESD SENSITIVE DEVICE 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. ABSOLUTE MAXIMUM RATINGS* Maximum Open-Collector Output Voltage (TMP03) . . +18 V *CAUTION 1Stresses 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. 2Digital inputs and outputs are protected, however, permanent damage may occur on unprotected units from high-energy electrostatic fields. Keep units in conduc- tive foam or packaging at all times until ready to use. Use proper antistatic handling procedures. 3Remove power before inserting or removing units from their sockets. Package Type Θ JA Θ JC Units TO-92 (T9) 162 1 120 °C/W SO-8 (S) 158 1 43 °C/W TSSOP (RU) 240 1 43 °C/W NOTE 1Θ JA is specified for device in socket (worst case conditions). DICE CHARACTERISTICS Die Size 0.050 × 0.060 inch, 3,000 sq. mils For additional DICE ordering information, refer to databook. ORDERING GUIDE Accuracy Temperature Model at +25 8C Range Package TMP03FT9 ± 3.0 XIND TO-92 TMP03FS ± 3.0 XIND SO-8 TMP03FRU ± 3.0 XIND TSSOP-8 TMP03GBC ± 3.0 +25 °C Die TMP04FT9 ± 3.0 XIND TO-92 TMP04FS ± 3.0 XIND SO-8 TMP04FRU ± 3.0 XIND TSSOP-8 TMP04GBC ± 3.0 +25 °C Die
REV. 0 –5– Table I. Counter Size and Clock Frequency Effects on Quantization Error Maximum Maximum Maximum Quantization Quantization Count Available Temp Required Frequency Error (+25 8C) Error (+77 8F) 4096 +125 °C 94 kHz 0.284 °C 0.512 °F 8192 +125 °C 188 kHz 0.142 °C 0.256 °F 16384 +125 °C 376 kHz 0.071 °C 0.128 °F Optimizing Counter Characteristics 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 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 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 Δ T = PDISS × Θ JA = 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 Δ T = PDISS × Θ JA = 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 PDISS = 0.6 V() 0.8 mA() T 2 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 ΔT = PDISS × Θ JA = 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 ΔT = PDISS × Θ JC = (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 + (T OBSERVED – TTMP03OUTPUT) A more complicated two-point calibration is also possible. This involves measuring the TMP03/TMP04 output at two temp- eratures, Temp1 and Temp2, and modifying the slope constant (normally 400) as follows: Slope Constant = Temp2 − Temp1 T1@ Temp1 T 2@ Temp1 − T1@ Temp2 T 2@ Temp2 where T1 and T2 are the output high and output low times, respectively.
REV. 0–12– Software for the interface is shown in Listing 1. The program monitors the TMP04 output, and turns the counters on and off to measure the duty cycle. The time that the output is high is measured by Timer 0, and the time that the output is low is measured by Timer 1. When the routine finishes, the results are available in Special Function Registers (SFRs) 08AH through 08DH. Listing 1. An 80C51 Software Routine for the TMP04 ; Test of a TMP04 interface to the 8051, ; using timer 0 and timer 1 to measure the duty cycle ; This program has three steps: ; 1. Clear the timer registers, then wait for a low-to- ; high transition on input P1.0 (which is connected ; to the output of the TMP04). ; 2. When P1.0 goes high, timer 0 starts. The program ; then loops, testing P1.0. ; 3. When P1.0 goes low, timer 0 stops & timer 1 starts. The ; program loops until P1.0 goes low, when timer 1 stops ; and the TMP04’s T1 and T2 values are stored in Special ; Function registers 8AH through 8DH (TL0 through TH1). ; Primary controls $MOD51 $TITLE(TMP04 Interface, Using T0 and T1) $PAGEWIDTH(80) $DEBUG $OBJECT ; Variable declarations PORT1 DATA 90H ;SFR register for port 1 ;TCON DATA 88H ;timer control ;TMOD DATA 89H ;timer mode ;TH0 DATA 8CH ;timer 0 hi byte ;TH1 DATA 8DH ;timer 1 hi byte ;TL0 DATA 8AH ;timer 0 lo byte ;TL1 DATA 8BH ;timer 1 low byte ORG 100H ;arbitrary start READ_TMP04: MOV A,#00 ;clear the MOV TH0,A ; counters MOV TH1,A ; first MOV TL0,A ; MOV TL1,A ; WAIT_LO: JB PORT1.0,WAIT_LO ;wait for TMP04 output to go low MOV A,#11H ;get ready to start timer0 MOV TMOD,A WAIT_HI: JNB PORT1.0,WAIT_HI ;wait for output to go high ;Timer 0 runs while TMP04 output is high SETB TCON.4 ;start timer 0 WAITTIMER0: JB PORT1.0,WAITTIMER0 CLR TCON.4 ;shut off timer 0 ;Timer 1 runs while TMP04 output is low SETB TCON.6 ;start timer 1 WAITTIMER1: JNB PORT1.0,WAITTIMER1 CLR TCON.6 ;stop timer 1 MOV A,#0H ;get ready to disable timers MOV TMOD,A RET END
continues to run while the program monitors the input port. nominal error caused by the 2 µs delay is only about ± 0.15°C. pin is required for the interface (Figure 35). Figure 35. Interfacing the TMP04 to the ADSP-210x Digital a lower oscillator frequency. prescaler register will divide the crystal oscillator frequency by n. counter is reloaded and runs until the TMP04 output goes low. using the scale factor of Equation 1. timing the output pulse widths.
- The circuit measures the output pulse widths with a
oscillator, have a maximum period of 65 ms. count the next TMP04 output phase. condition (such as a broken connection to the TMP04) exists.
REV. 0–14– Listing 2. Software Routine for the TMP04-to-ADSP-210x Interface { ADSP-21XX Temperature Measurement Routine TEMPERAT.DSP Altered Registers: ax0, ay0, af, ar, si, sr0, my0, mr0, mr1, mr2. Return value: ar —> temperature result in 14.2 format Computation time: 2 * TMP04 output period .MODULE/RAM/BOOT=0 TEMPERAT; { Beginning TEMPERAT Program } .ENTRY TEMPMEAS; { Entry point of this subroutine } .CONST PRESCALER=4; .CONST TIMFULSCALE=0Xffff; TEMPMEAS: si=PRESCALER; { For timer prescaler } sr0=TIMFULSCALE; { Timer counter full scale } dm(0x3FFB)=si; { Timer Prescaler set up to 5 } si=TIMFULSCALE; { CLKin=10MHz,Timer Period=32.768ms } dm(0x3FFC)=si; { Timer Counter Register to 65535 } dm(0x3FFD)=si; { Timer Period Register to 65535 } imask=0x01; { Unmask Interrupt timer } TEST1: if not fi jump TEST1; { Check for FI=1 } TEST0: if fi jump TEST0; { Check for FI=0 to locate transition } ena timer; { Enable timer, count at a 500ns rate } COUNT2: if not fi jump COUNT2; { Check for FI=1 to stop count } dis timer; ay0=dm(0x3FFC); { Save counter=T2 in ALU register } ar=sr0-ay0; ax0=ar; dm(0x3FFC)=si; { Reload counter at full scale } ena timer; COUNT1: if fi jump COUNT1; { Check for FI=0 to stop count } dis timer; ay0=dm(0x3FFC); { Save counter=T1 in ALU register } ar=sr0-ay0; my0=400; mr=ar*my0(uu); { mr=400*T1 } ay0=mr0; { af=MSW of dividend, ay0=LSW } ar=mr1; af=pass ar; { ax0=16-bit divisor } COMPUTE: astat=0; { To clear AQ flag } divq ax0; divq ax0; { Division 400*T1/T2 } divq ax0; divq ax0; { with 0.3 < T1/T2 < 0.7 } 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; { Result in ay0 } ax0=0x03AC; { ax0=235*4 } ar=ax0-ay0; { ar=235-400*T1/T2, result in øC } rts; { format 14.2 } .ENDMOD; { End of the subprogram }
Figure 36. A Hardware Interface for the TMP04 source can be inferred from the TMP03/TMP04 output. dissipation microprocessor or other IC is shown in Figure 37.
the minimum settling time resolution is 27 ms. without requiring an A/D converter. Figure 37. Monitoring the Temperature of a High Power Dimensions shown in inches and (mm).