IL235Z INTEGRATED CIRCUIT OF TEMPERATURE SENSOR (analog LM235Z, SGS-Thomson) Microcircuit IL235Z is precision temperature sensor with calibration capacity . Microcircuit operates as Zener diode with brake down voltage being in direct proportion to to absolute temperature (10 mV/OK). Full dynamic resistance of the circuit is less than 1 Оhm at operation current 450 µА...5 mА. The sensor calibrated at the temperature 25OС,has typical error less than 1OС in the temperature range above 100OС. The peculiarity of the circuit IL235Z is the linear dependence of output voltage versus temperature. Packaged IC type: IC features • calibration in OК • initial measurement accuracy 1OK • range of operating supply current from 450 µА to 5 mА Full dynamic resistance less than 1 Оhm IL235Z, TO-92 Bottom view Figure 1 - Package pin definitions Figure 2 - circuitry IL235Z. Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by IL235Z Тable 1 - Maximum ratings Name of parameter Symbol Standard min IC current reverse direct IR IF Air operation temperature: * - constant mode - short-time Storage temperature max 15 10 -- Unit of measurement mA °С TOPER - 40 125 -65 Tstg 125 150 150 °С Note - *TJ ≤ 150°С Тable 2 – Temperature parameters. Name of parameter Symbol min output voltage, V Non-calibrated temperature error temperature error at calibration 25°С Calibrated error in extended temperature range Non-linearity of temperature characteristic UOUT ∆Т1 2,95 - ∆Т2 ∆Т3 Standard Type max Test conditions Temperature Unit IR = 1 mA °С 25 25 -45 ÷ 125 -45 ÷ 125 °С Тcase=Тmax -45 ÷ 125 °С -55 ÷ 150 °С 3,01 3 5 1,5 IR = 1 mA IR = 1 mA - 2,98 1 2 0,5 - 2 - V °С periodical ∆Т4 - 0,3 1 IR = 1 mA Тable 3 – Electrical parameters. Name of parameter Measurement of output voltage in supply currents range Изменение выходного напряжения в диапазоне питающих токов Dynamic impedance Temperature coefficient of output voltage Time constant: -still air -speed of air is 0,5 m/с - agitated oil Time stability Symbo l min ∆UOUT - ∆R1 ТКН - τТ Standard type. max Test conditions Temperat ure °С -45 ÷ 125 mV 10 0,45 mА ≤ IR ≤ 5 mА 0,5 +10 - IR = 1 mА - 25 25 Ohm mV/°С - -45 ÷ 125 С 80 10 1 0,2 2,5 °С/ 1000ч Note – Precise measurements done in agitated oil bath. For other conditions there should be taking into consideration self-heating . ТСТАБ Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by - 125 IL235Z Calibration error, (оС) Change of reverse voltage, (mV) Temperature , (оС) Reverse current, (mА) Figure 3 –Reverse voltage versus reverse current Figure 4 – Calibration error versus temperature Reverse current, (mА) Input and output voltage, (V) Time, (mks) reverse voltage, (V) Figure 5 – Reverse current versus reverse voltage Figure 6 – Output signal response time Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by IL235Z Noise density (nV/√Hz) Direct dynamic resistance , (Оhm) Frequency, (Hz) Frequency, (Hz) Figure 7 – Dynamic resistance versus frequency Figure 8 – Noise voltage Thermal resistance, (оС/Wt) Time constant, ( с ) Air motion speed, (m/с) Air motion speed, (m/с) Figure 9 – Thermal resistance versus air motion speed Figure 10 – Time constant versus air motion speed Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by IL235Z Heat conduction , (%) Heat conduction, (%) Time, (min) Time, (min) Figure 11 – Time dependence of heat conduction in still air Figure 12 – Time dependence of heat conduction in agitated oil Direct voltage, (V) Direct current, (mА) Figure 13 – Dependence of direct voltage on direct current Information for application. There is a simple technique of the device calibration for improving precision of temperature measurement (see typical application circuits). Calibration of the device occurs in one spot as the IC output voltage is proportional to absolute temperature with sensor voltage extrapolation to 0 V at 0оК (-273,15оС). The errors in dependence of output voltage on temperature are determined only by characteristic incline. Therefore bias calibration at one temperature corrects errors in the whole temperature range. Output voltage of calibrated or non calibrated circuit may be derived from the following equation: VOT = VOTO T ; To where Т – unknown temperature; ТО – reference temperature (in оК). Nominally IC output calibrated to the value 10 mV/ оК. To ensure measurement precision they apply some rules. Degradation of the precision when Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by IL235Z self-heating is proper to any devices of temperature sensors. The circuit should operate at low operating current but sufficient for controlling the sensor and its calibration circuit at maximum operating temperature. When using the sensor in the field with constant thermal resistance, error when self-heating may be reduced by external calibration. It can be done at the circuit bias when applying temperaturestabilized current. Thus heating will be proportional to Zener diode voltage. In this case error when self-heating is proportional to absolute temperature as the error of scaling coefficient. Typical application circuits. Figure 14 – Basic circuit of temperature sensor Figure 16 – Temperature sensor with external calibration * Figure 15 – Application circuit of temperature sensor with wide range supply voltage Figure 17 – Sequential sensor connection for increase of temperature bias voltage– Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by IL235Z Figure 18 – Circuit of isolated temperature sensor Figure 19 – Temperature regulator Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by IL235Z IL235Z Figure 20 – Thermal sensor with 1000 scale * Calibration for 2,7315 V on output of LM308 Figure 21 – Differential temperature sensor Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by IL235Z Thermo couple R3 Thermo electrical coefficient 377 Оhm 52,3 µV/оС T 308 Оhm 42,8 µV/оС K 293 Оhm 40,8 µV/оС S 45,8 Оhm 6,4 µV/оС J Adjustment: compensation of sensor and resistor tolerances 1 Selection of 1N4568 2 Adjustment of voltage drop on element R3 by the resistor R1 to obtain the value of thermoelectrical coefficient, multiplied by the ambient temperature (in K degrees). 3 Selection of IL235Z and adjustment of R2 for setting voltage drop on the element R3 according to thermocouple type J – 14,32 mV T – 11,79 mV K – 11,17 mV S – 1,768 mV Figure 22 – Circuit of cold junction compensation (compensation for ground thermocouple) *Value of R3 nominal for this thermocouple type Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by IL235Z Thermocouple J R3 R4 1050 Оhm 365 Оhm Тhermoelectrical coefficient 52,3 µV/оС T 856 Оhm 315 Оhm 42,8 µV/оС K 816 Оhm 300 Оhm 40,8 µV/оС S 128 Оhm 46,3 Оhm 6,4 µV/оС Adjustment: compensation of sensor and resistor tolerances 1 Adjustment by the resistor R1 for obtaining voltage drop on the element R3, equal to thermoelectrical coefficient multiplied by the ambient temperature (in K degrees) 2 Adjustment of the resistor R2 for obtaining some voltage drop on the element R4 according to thermocouple type J – 14,32 mV T – 11,79 mV K – 11,17 mV S – 1,768 mV Figure 23 – Circuit of cold junction compensation with unipolar supply *Value of R3 and R4 nominals for this thermocouple type Korzhenevskogo 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: [email protected] URL: www.bms.by