Amplifier For isolated temperature measurements, Figure 19 provides an application solution using the INA114 or INA128 devices, feeding the input stage of the ISO124 device. The table provides suggested resistor values based on the type of thermistor used in the application. +15V 2 10.0V 6 4 REF102 Thermocouple R4 +15V –15V +15V –15V R1 27kΩ +15V Isothermal 2 1 Block with 7 2 ISO124 1N4148(1) +In 9 1 INA114 6 15 10 7 R G or V OUT R 8 INA128 5 8 1MΩ 2 –In 4 16 3 R3 R5 100Ω 50Ω –15V SEEBACK R6 100 ISA COEFFICIENT R2 R4 Zero Adj TYPE MATERIAL (µV/°C) (R3= 100Ω) (R5+ R6= 100Ω) Chromel E Constantan 58.5 3.48kΩ
Thermocouple R R 1 4 +15V –15V +15V –15V 27k +15V Isothermal 2 1 Block with 2 (1) 7 ISO124 1N4148 +In 9 INA114 10 7 1 or 6 15 V RG OUT R 2 8 INA128 5 8 1M –In 4 16 3 R 3 R5 100 50 –15V SEEBACK R 100 ISA COEFFICIENT R 2 R4 6 TYPE MATERIAL (µV/°C) (R = 100 ) (R + R = 100 ) Zero Adj 3 5 6 Chromel E Constantan
noise and higher accuracy with high impedance sources. With source imped- ances of 2k to 50k the INA114 may provide lower offset voltage and drift. For very low source impedance (≤1k ), Crystal or the INA103 may provide improved accuracy and lower Ceramic INA111 noise. Transducer OFFSET TRIMMING 1M 1M
noise and higher accuracy with high impedance sources. With source imped- ances of 2k to 50k the INA114 may provide lower offset voltage and drift. For very low source impedance (≤1k ), Crystal or the INA103 may provide improved accuracy and lower Ceramic INA111 noise. Transducer OFFSET TRIMMING 1M 1M
noise and higher accuracy with high impedance sources. With source imped- ances of 2k to 50k the INA114, INA128, or INA129 may Crystal or provide lower offset voltage and drift. For very low source Ceramic INA121 impedance (≤1k ), the INA103 may provide improved Transducer accuracy and lower noise. At
noise and higher accuracy with high impedance sources. With source imped- ances of 2k to 50k the INA114, INA128, or INA129 may Crystal or provide lower offset voltage and drift. For very low source Ceramic INA121 impedance (≤1k ), the INA103 may provide improved Transducer accuracy and lower noise. At
RELATED PRODUCTS ● LOW COST PRODUCT FEATURES INA337 Precision, 0µV/°C Drift, Specified °C to +12°C INA114 50µV V , 0.5nA I , 115dB CMR, 3mA I , 0.25µV/°C Drift APPLICATIONS OS B Q INA118 50µV VOS, 1nABI , 120dB CMR, 385QA I , 0.5µV/°C Drift ● LOW-LEVEL TRANSDUCER AMPLIFIER FOR INA122 250µV VOS –10nA B
Bild
Bild
Bild
Bild
Bild
Bild
Bild
