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low power programmable temperature controller tmp01 rev. e 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 that may result from its use. specifications subject to change without notice. no license is granted by implication or otherwise under any patent or patent rights of analog devices. trademarks and registered trademarks are the property of their respective owners. one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781.329.4700 www.analog.com fax: 781.461.3113 ?1993C2009 analog devices, inc. all rights reserved. features ?55c to +125c (?67f to +257f) operation 1.0c accuracy over temperature (typ) temperature-proportional voltage output user-programmable temperature trip points user-programmable hysteresis 20 ma open-collector trip point outputs ttl/cmos compatible single-supply operation (4.5 v to 13.2 v) pdip, soic, and to-99 packages applications over/under temperature sensor and alarm board-level temperature sensing temperature controllers electronic thermostats thermal protection hvac systems industrial process control remote sensors functional block diagram vptat v+ temperature sensor and voltage reference 2.5v sensor 1 2 3 4 8 7 6 5 hysteresis generator window comparator tmp01 vref set high set low gnd under over r1 r2 r3 0 0333-001 figure 1. general description the tmp01 is a temperature sensor that generates a voltage output proportional to absolute temperature and a control signal from one of two outputs when the device is either above or below a specific temperature range. both the high/low temperature trip points and hysteresis (overshoot) band are determined by user-selected external resistors. for high volume production, these resistors are available on board. the tmp01 consists of a band gap voltage reference combined with a pair of matched comparators. the reference provides both a constant 2.5 v output and a voltage proportional to absolute temperature (vptat) which has a precise temperature coefficient of 5 mv/k and is 1.49 v (nominal) at 25c. the comparators compare vptat with the externally set tempera- ture trip points and generate an open-collector output signal when one of their respective thresholds has been exceeded. hysteresis is also programmed by the external resistor chain and is determined by the total current drawn out of the 2.5 v reference. this current is mirrored and used to generate a hysteresis offset voltage of the appropriate polarity after a comparator has been tripped. the comparators are connected in parallel, which guarantees that there is no hysteresis overlap and eliminates erratic transitions between adjacent trip zones. the tmp01 utilizes proprietary thin-film resistors in conjunc- tion with production laser trimming to maintain a temperature accuracy of 1c (typical) over the rated temperature range, with excellent linearity. the open-collector outputs are capable of sinking 20 ma, enabling the tmp01 to drive control relays directly. operating from a 5 v supply, quiescent current is only 500 a (max). the tmp01 is available in 8-pin mini pdip, soic, and to-99 packages.
tmp01 rev. e | page 2 of 20 table of contents features .............................................................................................. 1 ? applications ....................................................................................... 1 ? functional block diagram .............................................................. 1 ? general description ......................................................................... 1 ? revision history ............................................................................... 2 ? specifications ..................................................................................... 3 ? tmp01est, tmp01fp, tmp01fs ............................................. 3 ? tmp01fj ........................................................................................ 4 ? absolute maximum ratings ............................................................ 5 ? typical performance characteristics ............................................. 6 ? theory of operation ........................................................................ 8 ? temperature hysteresis ............................................................... 8 ? programming the tmp01 ........................................................... 8 ? understanding error sources ..................................................... 9 ? safety considerations in heating and cooling system design ............................................................................................ 9 ? applications information .............................................................. 10 ? self-heating effects .................................................................... 10 ? buffering the voltage reference ............................................... 10 ? preserving accuracy over wide temperature range operation .................................................................................... 10 ? thermal response time ........................................................... 10 ? switching loads with the open-collector outputs .............. 11 ? high current switching ............................................................ 12 ? buffering the temperature output pin ................................... 13 ? differential transmitter ............................................................. 13 ? 4 ma to 20 ma current loop .................................................. 13 ? temperature-to-frequency converter .................................... 14 ? isolation amplifier ..................................................................... 15 ? out-of-range warning .............................................................. 15 ? translating 5 mv/k to 10 mv/c ............................................ 16 ? translating vptat to the fahrenheit scale ........................... 16 ? outline dimensions ....................................................................... 17 ? ordering guide .......................................................................... 18 ? revision history 7/09rev. d to rev. e updated format .................................................................. universal updated outline dimensions ....................................................... 18 changes to ordering guide .......................................................... 19 1/02rev. c: rev. d edits to general descriptions section ........................................... 1 edits to specifications section ........................................................ 2 edits to wafer test limits section.................................................. 4 edits to dice characteristics section ............................................. 4 edits to ordering guide .................................................................. 5 7/93revision 0: initial version
tmp01 rev. e | page 3 of 20 specifications tmp01es, tmp01fp, tmp01fs pdip and soic packages. v+ = 5 v, gnd = o v, ?40c t a +85c, unless otherwise noted. table 1. parameter symbol conditions min typ max unit inputs set high, set low offset voltage v os 0.25 mv offset voltage drift tcv os 3 v/c input bias current, e grade i b 25 50 na input bias current, f grade i b 25 100 na output vptat output voltage vptat t a = 25c, no load 1.49 v scale factor 1 tcv ptat 5 mv/k temperature accuracy, e grade t a = 25c, no load ?1.5 0.5 1.5 c temperature accuracy, f grade t a = 25c, no load ?3 1.0 3 c temperature accuracy, e grade 10c < t a < 40c, no load 0.75 c temperature accuracy, f grade 10c < t a < 40c, no load 1.5 c temperature accuracy, e grade ?40c < t a < 85c, no load ?3.0 1 3.0 c temperature accuracy, f grade ?40c < t a < 85c, no load ?5.0 2 5.0 c temperature accuracy, e grade ?55c < t a < 125c, no load 1.5 c temperature accuracy, f grade vptat ?55c < t a < 125c, no load 2.5 c repeatability error 2 0.25 degree long-term drift error 3 , 4 0.25 0.5 degree power supply rejection ratio psrr t a = 25c, 4.5 v v+ 13.2 v 0.02 0.1 %/v output vref output voltage, e grade vref t a = 25c, no load 2.495 2.500 2.505 v output voltage, f grade vref t a = 25c, no load 2.490 2.500 2.510 v output voltage, e grade vref ?40c < t a < 85c, no load 2.490 2.500 2.510 v output voltage, f grade vref ?40c < t a < 85c, no load 2.485 2.500 2.515 v output voltage, e grade vref ?55c < t a < 125c, no load 2.5 0.01 v output voltage, f grade vref ?55c < t a < 125c, no load 2.5 0.015 v drift tc vref ?10 ppm/c line regulation 4.5 v v+ 13.2 v 0.01 0.05 %/v load regulation 10 a i vref 500 a 0.1 0.25 %/ma output current, zero hysteresis iv ref 7 a hysteresis current scale factor 1 sf hys 5.0 a/c turn-on settling time to rated accuracy 25 s open-collector outputs over , under output low voltage v ol i sink = 1.6 ma 0.25 0.4 v v ol i sink = 20 ma 0.6 v output leakage current i oh v+ = 12 v 1 100 a fall time t hl see figure 2 40 ns power supply supply range v+ 4.5 13.2 v supply current i sy unloaded, +v = 5 v 400 500 a i sy unloaded, +v = 13.2 v 450 800 a power dissipation p diss +v = 5 v 2.0 2.5 mw 1 k = c + 273.15. 2 maximum deviation between 25c readings after temperature cycl ing between ?55c and +125c. 3 guaranteed but not tested. 4 observed in a group sample over an acce lerated life te st of 500 hours at 150c.
tmp01 rev. e | page 4 of 20 v + 1k? 20pf 00333-002 figure 2. test load tmp01fj to-99 metal can package. v+ = 5 v, gnd = 0 v, ?40c t a +85c, unless otherwise noted. table 2. parameter symbol conditions min typ max unit inputs set high, set low offset voltage v os 0.25 mv offset voltage drift tcv os 3 v/c input bias current, f grade i b 25 100 na output vptat output voltage vptat t a = 25c, no load 1.49 v scale factor 1 tcv ptat 5 mv/k temperature accuracy, f grade t a = 25c, no load ?3 1.0 3 c temperature accuracy, f grade 10c < t a < 40c, no load 1.5 c temperature accuracy, f grade ?40c < t a < 85c, no load ?5.0 2 5.0 c temperature accuracy, f grade vptat ?55c < t a < 125c, no load 2.5 c repeatability error 2 0.25 degree long-term drift error 3, 4 0.25 0.5 degree power supply rejection ratio psrr t a = 25c, 4.5 v v+ 13.2 v 0.02 0.1 %/v output vref output voltage, f grade vref t a = 25c, no load 2.490 2.500 2.510 v output voltage, f grade vref ?40c < t a < 85c, no load 2.485 2.500 2.515 v output voltage, f grade vref ?55c < t a < 125c, no load 2.5 0.015 v drift tc vref ?10 ppm/c line regulation 4.5 v v+ 13.2 v 0.01 0.05 %/v load regulation 10 a i vref 500 a 0.1 0.25 %/ma output current, zero hysteresis iv ref 7 a hysteresis current scale factor 1 sf hys 5.0 a/c turn-on settling time to rated accuracy 25 s open-collector outputs over , under output low voltage v ol i sink = 1.6 ma 0.25 0.4 v v ol i sink = 20 ma 0.6 v output leakage current i oh v+ = 12 v 1 100 a fall time t hl see figure 2 40 ns power supply supply range v+ 4.5 13.2 v supply current i sy unloaded, +v = 5 v 400 500 a i sy unloaded, +v = 13.2 v 450 800 a power dissipation p diss +v = 5 v 2.0 2.5 mw 1 k = c + 273.15. 2 maximum deviation between 25c re adings after temperature cyclin g between ?55c and +125c. 3 guaranteed but not tested. 4 observed in a group sample over an acce lerated life test of 500 hours at 150c.
tmp01 rev. e | page 5 of 20 absolute maximum ratings table 3. parameter rating maximum supply voltage ?0.3 v to +15 v maximum input voltage (set high, set low) ?0.3 v to v+ +0.3 v maximum output current (vref, vptat) 2 ma maximum output current (open-collector outputs) 50 ma maximum output voltage (open-collector outputs) 15 v operating temperature range ?55c to +150c die junction temperature 150c storage temperature range ?65c to +150c lead temperature (soldering 60 sec) 300c 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. remove power before inserting or removing units from their sockets. table 4. package type ja jc unit 8-lead pdip (n-8) 103 1 43 c/w 8-lead soic (r-8) 158 2 43 c/w 8-pin to-99 can (h-08) 150 1 18 c/w 1 ja is specified for device in socket (worst-case conditions). stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2 ja is specified for device mounted on pcb. esd caution
tmp01 rev. e | page 6 of 20 typical performance characteristics 20 51 5 01 0 supply voltage (v) supply current (a) 550 350 400 375 450 425 475 500 525 +25c +125c +85c ?55c ?40c 00333-003 figure 3. supply current vs. supply voltage 5.0 3.0 4.5 3.5 4.0 125 ?75 ?50 ?25 100 75 5025 0 temperature (c) minimum supply voltage (v) 00333-004 figure 4. minimum supply voltage vs. temperature 2.0 1.0 0.5 ?2.0 1.5 ?1.0 ?1.5 ?0.5 0 125 ?75 ?50 ?25 100 75 v+ = 5v 5025 0 temperature (c) vptat error (c) 00333-005 figure 5. vptat accuracy vs. temperature 2.508 2.506 2.504 2.496 2.500 2.498 2.502 125 ?75 ?50 ?25 100 75 v+ = 5v 50 25 0 temperature (c) vref (v) 00333-006 figure 6. vref accuracy vs. temperature 6 0 3 1 2 5 4 50 10 40 03 0 20 v c = 15v v+ = 5v t a = 25c i c (ma) v ce (v) 00333-007 figure 7. open-collector output ( over , under ) saturation voltage vs. output current x ? 3 x + 3 2.510 2.490 2.496 2.492 2.494 2.502 2.498 2.500 2.504 2.506 2.508 1000 200 800 0 400 600 x curves not normalized extrapolated from operating life data t = hours of operation at 125c; v+ = 5v vref (v) 0 0333-008 figure 8. vref long term drift accelerated by burn-in
tmp01 rev. e | page 7 of 20 100 1m 1k 100k 10k ?20 100 40 20 0 60 80 frequency (hz) psrr (db) v+ = 5v i vref = 10a 00333-009 figure 9. vref power supply rejection vs. frequency 1.0 0.1 0.01 offset voltage (mv) v+ = 5v i vref = 7.5a 00333-010 figure 10. set high, set low inpu t offset voltage vs. temperature 8 0 2 1 4 3 5 6 7 ?0.4 ?0.24 ?0.32 0 ?0.16 0.16 ?0.08 0.08 offset (mv) number of devices v+ = 5v t a = 25c i vref = 5a 00333-011 figure 11. comparator input offset distribution 7.2 7 6.2 6.8 6.6 8 6.4 7.87.67.4 reference current (a) number of devices 10 0 2 1 4 3 5 6 7 8 9 v+ = 5v t a = 25c 00333-012 figure 12. zero hysteresis current distribution
tmp01 rev. e | page 8 of 20 theory of operation the tmp01 is a linear voltage-output temperature sensor, with a window comparator that can be programmed by the user to activate one of two open-collector outputs when a predeter- mined temperature setpoint voltage has been exceeded. a low drift voltage reference is available for setpoint programming. the temperature sensor is basically a very accurate, temperature compensated, band gap-type voltage reference with a buffered output voltage proportional to absolute temperature (vptat), accurately trimmed to a scale factor of 5 mv/k. the low drift 2.5 v reference output vref is easily divided externally with fixed resistors or potentiometers to accurately establish the programmed heat/cool setpoints, independent of temperature. alternatively, the setpoint voltages can be supplied by other ground referenced voltage sources such as user- programmed dacs or controllers. the high and low setpoint voltages are compared to the temperature sensor voltage, thus creating a two-temperature thermostat function. in addition, the total output current of the reference (i vref ) determines the magnitude of the temperature hysteresis band. the open collector outputs of the comparators can be used to control a wide variety of devices. vptat v+ window comparator temperature output hysteresis current current mirror hysteresis voltage enable tmp01 vref set high set low gnd under over 8 5 6 7 1 4 3 2 voltage reference and sensor 1k ? i hys 00333-013 figure 13. detailed block diagram temperature hysteresis the temperature hysteresis is the number of degrees beyond the original setpoint temperature that must be sensed by the tmp01 before the setpoint comparator is reset and the output disabled. figure 14 shows the hysteresis profile. the hysteresis is programmed by the user by setting a specific load on the reference voltage output vref. this output current i vref is also called the hysteresis current, which is mirrored internally and fed to a buffer with an analog switch. hysteresis high hysteresis low lo hi output voltage over, under temperature hysteresis high = hysteresis low t setlow t sethigh 00333-014 figure 14. tmp01 hysteresis profile after a temperature setpoint is exceeded and a comparator tripped, the buffer output is enabled. the output is a current of the appropriate polarity that generates a hysteresis offset volt- age across an internal 1000 resistor at the comparator input. the comparator output remains on until the voltage at the comparator input, now equal to the temperature sensor voltage vptat summed with the hysteresis offset, returns to the programmed setpoint voltage. the comparator then returns low, deactivating the open-collector output and disabling the hysteresis current buffer output. the scale factor for the programmed hysteresis current is: i hys = i vref = 5 a/c + 7 a thus, since vref = 2.5 v, with a reference load resistance of 357 k or greater (output current 7 a or less), the temper- ature setpoint hysteresis is zero degrees. larger values of load resistance only decrease the output current below 7 a and have no effect on the operation of the device. the amount of hysteresis is determined by selecting a value of load resistance for vref. programming the tmp01 in the basic fixed setpoint application utilizing a simple resistor ladder voltage divider, the desired temperature setpoints are programmed in the following sequence: 1. select the desired hysteresis temperature. 2. calculate the hysteresis current i vref . 3. select the desired setpoint temperatures. 4. calculate the individual resistor divider ladder values needed to develop the desired comparator setpoint voltages at set high and set low.
tmp01 rev. e | page 9 of 20 th e hysteresis current is readily calculated. for example, for 2 degrees of hysteresis, i vref = 17 a. next, the setpoint voltages, v sethigh and v setlow , are determined using the vptat scale factor of 5 mv/k = 5 mv/(c + 273.15), which is 1.49 v for 25c. then, calculate the divider resistors, based on those setpoints. the equations used to calculate the resistors are v sethigh = ( t sethigh + 273.15) (5 mv/c) v setlow = ( t setlow + 273.15) (5 mv/c) r 1 (k) = ( v vref ? v sethigh )/ i vref = (2.5 v ? v sethigh )/ i vref r2 (k) = (v sethigh ? v setlow )/ i vref r3 (k) = v setlow / i vref vptat v+ 1 2 3 4 8 7 6 5 tmp01 v vref = 2.5v v sethigh v setlow gnd under over (v vref ? v sethigh )/i vref = r1 (v sethigh ? v setlow )/i vref = r2 v setlow /i vref = r3 i vref 00333-015 figure 15. tmp01 setpoint programming the total r1 + r2 + r3 is equal to the load resistance needed to draw the desired hysteresis current from the reference, or i vref . the formulas shown above are also helpful in understanding the calculation of temperature setpoint voltages in circuits other than the standard two-temperature thermostat. if a setpoint function is not needed, the appropriate comparator should be disabled. set high can be disabled by tying it to v+, set low by tying it to gnd. either output can be left unconnected. v ptat k c f 1.09 1.24 1.99 1.865 1.74 1.615 1.49 1.365 218 248 398 373 348 323 298 273 ?67 ?25 257 200 212 150 100 50 77 32 0 ?55 ?25 125 100 75 50 25 0 ?18 0 0333-016 figure 16. temperaturevptat scale understanding error sources the accuracy of the vptat sensor output is well characterized and specified; however, preserving this accuracy in a heating or cooling control system requires some attention to minimizing the various potential error sources. the internal sources of setpoint programming error include the initial tolerances and temperature drifts of the reference voltage vref, the setpoint comparator input offset voltage and bias current, and the hysteresis current scale factor. when evaluating setpoint programming errors, remember that any vref error contribution at the comparator inputs is reduced by the resistor divider ratios. the comparator input bias current (inputs set high, set low) drops to less than 1 na (typ) when the comparator is tripped. this can account for some setpoint voltage error, equal to the change in bias current times the effective setpoint divider ladder resistance to ground. the thermal mass of the tmp01 package and the degree of thermal coupling to the surrounding circuitry are the largest factors in determining the rate of thermal settling, which ultimately determines the rate at which the desired temperature measurement accuracy may be reached. thus, allow sufficient time for the device to reach the final temperature. the typical thermal time constant for the plastic package is approximately 140 seconds in still air. therefore, to reach the final temperature accuracy within 1%, for a temperature change of 60 degrees, a settling time of 5 time constants, or 12 minutes, is necessary. the setpoint comparator input offset voltage and zero hyster- esis current affect setpoint error. while the 7 a zero hysteresis current allows the user to program the tmp01 with moderate resistor divider values, it does vary somewhat from device to device, causing slight variations in the actual hysteresis obtained in practice. comparator input offset directly impacts the pro- grammed setpoint voltage and thus the resulting hysteresis band, and must be included in error calculations. external error sources to consider are the accuracy of the pro- gramming resistors, grounding error voltages, and the overall problem of thermal gradients. the accuracy of the external programming resistors directly impacts the resulting setpoint accuracy. thus, in fixed-temperature applications, the user should select resistor tolerances appropriate to the desired programming accuracy. resistor temperature drift must be taken into account also. this effect can be minimized by selecting good quality components, and by keeping all com- ponents in close thermal proximity. applications requiring high measurement accuracy require great attention to detail regarding thermal gradients. careful circuit board layout, component placement, and protection from stray air currents are necessary to minimize common thermal error sources. also, the user should take care to keep the bottom of the set- point programming divider ladder as close to gnd (pin 4) as possible to minimize errors due to ir voltage drops and coup- ling of external noise sources. in any case, a 0.1 f capacitor for power supply bypassing is always recommended at the chip. safety considerations in heating and cooling system design designers should anticipate potential system fault conditions, which may result in significant safety hazards, which are outside the control of and cannot be corrected by the tmp01-based circuit. observe governmental and industrial regulations regarding safety requirements and standards for such designs where applicable.
tmp01 rev. e | page 10 of 20 applications information self-heating effects in some applications, the user should consider the effects of self-heating due to the power dissipated by the open-collector outputs, which are capable of sinking 20 ma continuously. under full load, the tmp01 open-collector output device is dissipating p diss = 0.6 v .020a = 12 mw which in a surface-mount soic package accounts for a temperature increase due to self-heating of t = p diss ja = .012 w 158c/w = 1.9c this self-heating effect directly affects the accuracy of the tmp01 and will, for example, cause the device to activate the over output 2 degrees early. bonding the package to a moderate heat sink limits the self- heating effect to approximately: t = p diss jc = .012 w 43c/w = 0.52c which is a much more tolerable error in most systems. the vref and vptat outputs are also capable of delivering sufficient current to contribute heating effects and should not be ignored. buffering the voltage reference the reference output vref is used to generate the temper- ature setpoint programming voltages for the tmp01 and also to determine the hysteresis temperature band by the reference load current i vref . the on-board output buffer amplifier is typically capable of 500 a output drive into as much as 50 pf load (maximum). exceeding this load affects the accuracy of the reference voltage, could cause thermal sensing errors due to dissipation, and may induce oscillations. selection of a low drift buffer functioning as a voltage follower with high input impedance ensures optimal reference accuracy, and does not affect the programmed hysteresis current. amplifiers which offer the low drift, low power consumption, and low cost appropriate to this application include the op295, and members of the op90, op97, op177 families, and others as shown in the following applications circuits. with excellent drift and noise characteristics, vref offers a good voltage reference for data acquisition and transducer excitation applications as well. output drift is typically better than ?10 ppm/c, with 315 nv/hz (typ) noise spectral density at 1 khz. preserving accuracy over wide temperature range operation the tmp01 is unique in offering both a wide range temper- ature sensor and the associated detection circuitry needed to implement a complete thermostatic control function in one monolithic device. while the voltage reference, setpoint comparators, and output buffer amplifiers have been carefully compensated to maintain accuracy over the specified temper- ature range, the user has an additional task in maintaining the accuracy over wide operating temperature ranges in the application. since the tmp01 is both sensor and control circuit, in many applications it is possible that the external components used to program and interface the device may be subjected to the same temperature extremes. thus, it may be necessary to locate components in close thermal proximity to minimize large temperature differentials, and to account for thermal drift errors, such as resistor matching tempcos, amplifier error drift, and the like, where appropriate. circuit design with the tmp01 requires a slightly different perspective regarding the thermal behavior of electronic components. thermal response time the time required for a temperature sensor to settle to a speci- fied accuracy is a function of the thermal mass of the sensor, 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 q, and can be thought of as the reciprocal of 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 tmp01 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.
tmp01 rev. e | page 11 of 20 switching loads with the open-collector outputs in many temperature sensing and control applications, some type of switching is required. whether it be to turn on a heater when the temperature goes below a minimum value or to turn off a motor that is overheating, the open-collector outputs over and under can be used. for the majority of applications, the switches used need to handle large currents on the order of 1 a and above. because the tmp01 is accurately measuring temperature, the open-collector outputs should handle less than 20 ma of current to minimize self-heating. the over and under outputs should not drive the equip- ment directly. instead, an external switching device is required to handle the large currents. some examples of these are relays, power mosfets, thyristors, igbts, and darlingtons. figure 17 through figure 21 show a variety of circuits where the tmp01 controls a switch. the main consideration in these circuits, such as the relay in figure 17 , is the current required to activate the switch. temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator tmp01 r1 r2 r3 motor shutdown 2604-12-311 coto in4001 or equiv. 12v 0 0333-017 figure 17. reed relay drive it is important to check the particular relay to ensure that the current needed to activate the coil does not exceed the tmp01s recommended output current of 20 ma. this is easily deter- mined by dividing the relay coil voltage by the specified coil resistance. keep in mind that the inductance of the relay creates large voltage spikes that can damage the tmp01 output unless protected by a commutation diode across the coil, as shown. the relay shown has a contact rating of 10 w maximum. if a relay capable of handling more power is desired, the larger contacts probably require a commensurately larger coil, with lower coil resistance and thus higher trigger current. as the contact power handling capability increases, so does the current needed for the coil. in some cases, an external driving transistor should be used to remove the current load on the tmp01. power fets are popular for handling a variety of high current dc loads. figure 18 shows the tmp01 driving a p-channel mosfet transistor for a simple heater circuit. when the out- put transistor turns on, the gate of the mosfet is pulled down to approximately 0.6 v, turning it on. for most mosfets, a gate-to-source voltage, or vgs, on the order of ?2 v to ?5 v is sufficient to turn the device on. figure 19 shows a similar circuit for turning on an n-channel mosfet, except that now the gate to source voltage is positive. for this reason, an external transistor must be used as an inverter so that the mosfet turns on when the under output pulls down. temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator nc = no connect tmp01 r1 r2 r3 nc nc irfr9024 or equiv. heating element 2.4k ? (12v) 1.2k ? (6v) 5% v+ + 00333-018 figure 18. driving a p-channel mosfet temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator nc = no connect tmp01 r1 r2 r3 nc nc irf130 2n1711 4.7k ? v+ 4.7k ? heating element 00333-019 figure 19. driving an n-channel mosfet isolated gate bipolar transistors (igbt) combine many of the benefits of power mosfets with bipolar transistors, and are used for a variety of high po wer applications. because igbts have a gate similar to mosfets, turning on and off the devices is relatively simple as shown in figure 20 . the turn-on voltage for the igbt shown (irgbc40s) is between 3.0 v and 5.5 v. this part has a continuous collector current rating of 50 a and a maximum collector-to-emitter voltage of 600 v, enabling it to work in very demanding applications. temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator nc = no connect tmp01 r1 r2 r3 nc nc irgbc40s 2n1711 4.7k ? v+ 4.7k ? motor control 00333-020 figure 20. driving an igbt
tmp01 rev. e | page 12 of 20 thus, the output taken from the collector of q2 is identical to the output of the tmp01. by picking a transistor that can accommodate large amounts of current, many high power devices can be switched. the last class of high power devices discussed here are thyristors, which includes scrs and triacs. triacs are a useful alternative to relays for switching ac line voltages. the 2n6073a shown in figure 21 is rated to handle 4a (rms). the opto- isolated moc3011 triac features excellent electrical isolation from the noisy ac line and complete control over the high power triac with only a few additional components. temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator q1 tmp01 r1 r2 r3 v+ 4.7k ? 2n1711 i c 00333-022 temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator load ac window comparator nc = no connect tmp01 r1 r2 r3 nc nc v+ = 5v 300 ? 6 5 4 1 2 3 150 ? 2n6073a moc9011 00333-021 figure 22. an external resistor minimizes self-heating temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator q1 tmp01 r1 r2 r3 v+ 4.7k ? 2n1711 q2 2n1711 i c 4.7k ? 00333-023 figure 21. controlling the 2n6073a triac high current switching internal dissipation due to large loads on the tmp01 outputs causes some temperature error due to self-heating. external transistors remove the load from the tmp01, so that virtually no power is dissipated in the internal transistors and no self- heating occurs. figure 22 through figure 24 show a few examples using external transistors. the simplest case, using a single transistor on the output to invert the output signal is shown in figure 22 . when the open collector of the tmp01 turns on and pulls the output down, the external transistor q1 base is pulled low, turning off the transistor. another transistor can be added to reinvert the signal as shown in figure 23 . now, when the output of the tmp01 is pulled down, the first transis- tor, q1, turns off and its collector goes high, which turns q2 on, pulling its collector low. figure 23. second transistor maintains polarity of tmp01 output an example of a higher power transistor is a standard darlington configuration as shown in figure 24 . the part chosen, tip-110, can handle 2 a continuous which is more than enough to control many high power relays. in fact, the darlington itself can be used as the switch, similar to mosfets and igbts. temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator tmp01 r1 r2 r3 v+ 4.7k ? 2n1711 relay 12 v tip-110 i c 4.7k ? motor switch 00333-024 figure 24. darlington transistor can handle large currents
tmp01 rev. e | page 13 of 20 buffering the temperature output pin the vptat sensor output is a low impedance dc output voltage with a 5 mv/k temperature coefficient, that is useful in multiple measurement and control applications. in many applications, this voltage needs to be transmitted to a central location for processing. the buffered vptat voltage output is capable of 500 a drive into 50 pf (maximum). consider external amplifiers for interfacing vptat to external circuitry to ensure accuracy, and to minimize loading which could create dissipation-induced temperature sensing errors. an excellent general-purpose buffer circuit using the op177 is shown in figure 25 . it is capable of driving over 10 ma, and remains stable under capacitive loads of up to 0.1 f. other interfacing ideas are also provided in this section. differential transmitter in noisy industrial environments, it is difficult to send an accurate analog signal over a significant distance. however, by sending the signal differentially on a wire pair, these errors can be significantly reduced. because the noise is picked up equally on both wires, a receiver with high common-mode input rejection can be used to cancel out the noise very effec- tively at the receiving end. figure 26 shows two amplifiers used to send the signal differentially, and an excellent differential receiver, the amp03, which features a common-mode rejection ratio of 95 db at dc and very low input and drift errors. temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator tmp01 op177 r1 r2 r3 vptat v out c l v + v? v+ 100 ? 10k ? 0.1f 0 0333-025 figure 25. buffer vptat to handle difficult loads 4 ma to 20 ma current loop another common method of transmitting a signal over long distances is to use a 4 ma to 20 ma loop, as shown in figure 27 . an advantage of using a 4 ma to 20 ma loop is that the accuracy of a current loop is not compromised by voltage drops across the line. one requirement of 4 ma to 20 ma circuits is that the remote end must receive all of its power from the loop, meaning that the circuit must consume less than 4 ma. operating from 5 v, the quiescent current of the tmp01 is 500 a maximum, and the op90s is 20 a maximum, totaling less than 4 ma. although not shown, the open collector outputs and temperature setting pins can be connected to do any local control of switching. temperature sensor and voltage reference vref vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator tmp01 1/2 op297 1/2 op297 amp03 r1 r2 r3 vptat v out v + 50 ? 10k ? 10k ? 50 ? v? v+ 10k ? 00333-026 figure 26. send the signal di fferentially for noise immunity
tmp01 rev. e | page 14 of 20 the current is proportional to the voltage on the vptat output, and is calibrated to 4 ma at a temperature of ?40c, to 20 ma for +85c. the main equation governing the operation of this circuit gives the current as a function of vptat ? ? ? ? ? ? ? ? ? ? ? ? + + ? = 2 5 1 13 3 2 5 6 1 r r rr rvref r rvptat r i out the resulting temperature coefficient of the output current is 128 a/c. 5 8 1 4 2n1711 vref gnd v+ vptat tmp01 op90 4?20ma 5v to 13.2v 7 4 3 6 2 r l r6 100 ? r1 243k ? r2 39.2k ? r3 100k ? r5 100k ? 00333-027 figure 27. 4ma to 20 ma current loop to determine the resistor values in this circuit, first note that vref remains constant over temperature. thus, the ratio of r5 over r2 must give a variation of i out from 4 ma to 20 ma as vptat varies from 1.165 v at ?40c to 1.79 v at +85c. the absolute value of the resistors is not important, only the ratio. for convenience, 100 k is chosen for r5. once r2 is calculated, the value of r3 and r1 is determined by substituting 4 ma for i out and 1.165 v for vptat and solving. the final values are shown in the circuit. the op90 is chosen for this circuit because of its ability to operate on a single supply and its high accuracy. for initial accuracy, a 10 k trim potentiometer can be included in series with r3, and the value of r3 lowered to 95 k. the potentiometer should be adjusted to produce an output current of 12.3 ma at 25c. temperature-to-frequ ency converter another common method of transmitting analog information is to convert a voltage to the frequency domain. this is easily done with any of the low cost monolithic voltage-to-frequency converters (vfcs) available, which feature a robust, open- collector digital output. a digital signal is immune to noise and voltage drops because the only important information is the frequency. as long as the conversions between temperature and frequency are done accurately, the temperature data can be successfully transmitted. a simple circuit to do this combines the tmp01 with an ad654 vfc, as shown in figure 28 . the ad654 outputs a square wave that is proportional to the dc input voltage according to the following equation: t in out crr v f )21(10 + = by simply connecting the vptat output to the input of the ad654, the 5 mv/c temperature coefficient gives a sensitivity of 25 hz/c, centered around 7.5 khz at 25c. the trimming resistor r2 is needed to calibrate the absolute accuracy of the ad654. for more information on that part, consult the ad654 data sheet. finally, the ad650 ca n be used to accurately convert the frequency back to a dc voltage on the receiving end. temperature sensor and voltage reference vref vptat vptat 1 2 3 4 8 7 6 5 hysteresis generator window comparator tmp01 r1 r2 r3 v + f out v+ v+ 4 3 1 2 5 ad654 osc 7 8 6 r1 1.8k ? r2 500 ? 5k ? c t 0.1f 00333-028 figure 28. temperature-to-frequency converter
tmp01 rev. e | page 15 of 20 temperature sensor and voltage reference vref vptat isolation barrier 1 2 3 4 8 7 6 5 hysteresis generator window comparator tmp01 op290 r1 r2 r3 v+ 604k ? 100k ? r1 470k ? v+ in4148 i 1 i 2 6 5 3 4 1 2 2.5v v+ ref43 4 6 2 1.16v to 1.7v 100k ? 680pf op290 7 4 3 6 2 v+ op90 7 4 3 6 2 il300xc 680pf 00333-029 figure 29. isolation amplifier isolation amplifier in many industrial applications, the sensor is located in an envi- ronment that needs to be electrically isolated from the central processing area. figure 29 shows a simple circuit that uses an 8-pin optoisolator (il300xc) that can operate across a 5,000 v barrier. ic1 (an op290 single-supply amplifier) is used to drive the led connected between pin 1 and pin 2. the feedback actually comes from the photodiode connected from pin 3 to pin 4. the op290 drives the led such that there is enough current generated in the photodiode to exactly equal the current derived from the vptat voltage across the 470 k resistor. on the receiving end, an op90 converts the current from the second photodiode to a voltage through its feedback resistor r2. note that the other amplifier in the dual op290 is used to buffer the 2.5 v reference voltage of the tmp01 for an accurate, low drift led bias level without affecting the programmed hyster- esis current. a ref43 (a precision 2.5 v reference) provides an accurate bias level at the receiving end. to understand this circuit, it helps to examine the overall equation for the output voltage. first, the current (i1) in the photodiode is set by k 470 v5.2 1 vptat i note that the il300xc has a gain of 0.73 (typical) with a minimum and maximum of 0.693 and 0.769, respectively. because this is less than 1.0, r2 must be larger than r1 to achieve overall unity gain. to show this, the full equation is 22 5.2 riv v out vptat vptatv v k 470 5.2 7.05.2 k 644 a trim is included for r2 to correct for the initial gain accuracy of the il300xc. to perform this trim, simply adjust for an output voltage equal to vptat at any particular temperature. for example, at room temperature, vptat = 1.49 v, so adjust r2 until v out = 1.49 v as well. both the ref43 and the op90 operate from a single supply, and contribute no significant error due to drift. in order to avoid the accuracy trim, and to reduce board space, complete isolation amplifiers are available, such as the high accuracy ad202. out-of-range warning by connecting the two open-collector outputs of the tmp01 together into a wired-or configuration, a temperature out- of-range warning signal is generated. this can be useful in sensitive equipment calibrated to work over a limited temper- ature range. r1, r2, and r3 in figure 30 are chosen to give a temperature range of 10c around room temperature (25c). thus, if the temperature in the equipment falls below 15c or rises above 35c, the over or under output, respectively, goes low and turns the led on. the led may be replaced with a simple pull- up resistor to give a logic output for controlling the instrument, or any of the switching devices discussed above can be used. temperature sensor and voltage reference vref vptat vptat led 1 2 3 4 8 7 6 5 hysteresis generator window comparator tmp01 r1 4 7.5k ? r2 4 .99k ? r3 71.5k ? v + 200 ? 00333-030 figure 30. out-of-range warning
tmp01 rev. e | page 16 of 20 translating 5 mv/k to 10 mv/c a useful circuit shown in figure 31 translates the vptat output voltage, which is calibrated in kelvins, into an output that can be read directly in degrees celsius on a voltmeter display. to accomplish this, an external amplifier is configured as a differential amplifier. the resistors are scaled so the vref voltage exactly cancels the vptat voltage at 0.0c. 5 1 +15v ?15v 10pf v out = (10mv/c) (v out = 0.0v @ t = 0.0c) vptat vref tmp01 op177 7 4 3 6 2 100k ? 100k ? 105k ? 4.22k ? 4.12k ? 487 ? 00333-031 figure 31. translating 5 mv/k to 10 mv/c however, the gain from vptat to the output is two, so that 5 mv/k becomes 10 mv/c. thus, for a temperature of 80c, the output voltage is 800 mv. circuit errors will be due prima- rily to the inaccuracies of the resistor values. using 1% resistors, the observed error was less than 10 mv, or 1c. the 10 pf feedback capacitor helps to ensure against oscillations. for better accuracy, an adjustment potentiometer can be added in series with either 100 k resistor. translating vptat to the fahrenheit scale a similar circuit to the one shown in figure 31 can be used to translate vptat into an output that can be read directly in degrees fahrenheit, with a scaling of 10 mv/f. only unity gain or less is available from the first stage differentiating circuit, so the second amplifier provides a gain of two to complete the conversion to the fahrenheit scale. using the circuit in figure 32 , a temperature of 0.0f gives an output of 0.00 v. at room temp- erature (70f), the output voltage is 700 mv. a ?40c to +85c operating range translates into ?40f to +185f. the errors are essentially the same as for the circuit in figure 31 . 5 1 +15v ?15v 10p f v out = 0.0v @ t = 0.0f (10mv/f) vptat vref tmp01 1/2 op297 7 4 3 6 2 100k ? 100k ? 90.9k ? 1.0k ? 1/2 op297 5 7 6 100k ? 6.49k ? 121 ? 100k ? 00333-032 figure 32. translating 5 mv/k to 10 mv/f
tmp01 rev. e | page 17 of 20 outline dimensions compliant to jedec standards ms-001 controlling dimensions are in inches; millimeter dimensions (in parentheses) are rounded-off inch equivalents for reference only and are not appropriate for use in design. corner leads may be configured as whole or half leads. 070606-a 0.022 (0.56) 0.018 (0.46) 0.014 (0.36) seating plane 0.015 (0.38) min 0.210 (5.33) max 0.150 (3.81) 0.130 (3.30) 0.115 (2.92) 0.070 (1.78) 0.060 (1.52) 0.045 (1.14) 8 1 4 5 0.280 (7.11) 0.250 (6.35) 0.240 (6.10) 0.100 (2.54) bsc 0.400 (10.16) 0.365 (9.27) 0.355 (9.02) 0.060 (1.52) max 0.430 (10.92) max 0.014 (0.36) 0.010 (0.25) 0.008 (0.20) 0.325 (8.26) 0.310 (7.87) 0.300 (7.62) 0.195 (4.95) 0.130 (3.30) 0.115 (2.92) 0.015 (0.38) gauge plane 0.005 (0.13) min figure 33. .8-lead plastic dual in-line package [pdip] narrow body (n-8) dimensions shown in inches and (millimeters) 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. compliant to jedec standards ms-012-a a 012407-a 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 0.50 (0.0196) 0.25 (0.0099) 45 8 0 1.75 (0.0688) 1.35 (0.0532) seating plane 0.25 (0.0098) 0.10 (0.0040) 4 1 85 5.00 (0.1968) 4.80 (0.1890) 4.00 (0.1574) 3.80 (0.1497) 1.27 (0.0500) bsc 6.20 (0.2441) 5.80 (0.2284) 0.51 (0.0201) 0.31 (0.0122) coplanarity 0.10 figure 34. 8-lead standard small outline package [soic_n] narrow body (r-8) dimensions shown in millimeters and (inches)
tmp01 rev. e | page 18 of 20 controlling dimensions are in inches; millimeter dimensions (in parentheses) are rounded-off inch equivalents for reference only and are not appropriate for use in design. compliant to jedec standards mo-002-ak 0.2500 (6.35) min 0.5000 (12.70) min 0.1850 (4.70) 0.1650 (4.19) reference plane 0.0500 (1.27) max 0.0190 (0.48) 0.0160 (0.41) 0.0210 (0.53) 0.0160 (0.41) 0.0400 (1.02) 0.0100 (0.25) 0.0400 (1.02) max 0.0340 (0.86) 0.0280 (0.71) 0.0450 (1.14) 0.0270 (0.69) 0.1600 (4.06) 0.1400 (3.56) 0.1000 (2.54) bsc 6 2 8 7 5 4 3 1 0.2000 (5.08) bsc 0.1000 (2.54) bsc 0.3700 (9.40) 0.3350 (8.51) 0.3350 (8.51) 0.3050 (7.75) 45 bsc base & seating plane 022306-a figure 35. 8-pin me tal header [to-99] (h-08) dimensions shown in inches and (millimeters) ordering guide model/grade temperature range pack age description package option tmp01es ?40c to +85c 8-lead soic_n r-8 tmp01es-reel ?40c to +85c 8-lead soic_n r-8 tmp01esz 1 ?40c to +85c 8-lead soic_n r-8 tmp01esz-reel 1 ?40c to +85c 8-lead soic_n r-8 tmp01fp ?40c to +85c 8-lead pdip n-8 tmp01fpz 1 ?40c to +85c 8-lead pdip n-8 tmp01fs ?40c to +85c 8-lead soic_n r-8 tmp01fs-reel ?40c to +85c 8-lead soic_n r-8 tmp01fs-reel7 ?40c to +85c 8-lead soic_n r-8 tmp01fsz 1 ?40c to +85c 8-lead soic_n r-8 tmp01fsz-reel 1 ?40c to +85c 8-lead soic_n r-8 tmp01fsz-reel7 1 ?40c to +85c 8-lead soic_n r-8 tmp01fj ?40c to +85c 8-pin metal header (to-99) h-08 1 z = rohs compliant part.
tmp01 rev. e | page 19 of 20 notes
tmp01 rev. e | page 20 of 20 notes ?1993C2009 analog devices, inc. all rights reserved. trademarks and registered trademarks are the prop erty of their respective owners. d00333-0-7/09(e)

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