AD8497 AD [Analog Devices], AD8497 Datasheet
AD8497
Available stocks
Related parts for AD8497
AD8497 Summary of contents
Page 1
... The AD8494 and AD8496 are precalibrated by laser wafer trimming to match the characteristics of J type (iron-constantan) thermocouples; the AD8495 and AD8497 are laser trimmed to match the characteristics of K type (chromel-alumel) thermo- couples. See Table 1 for the optimized ambient temperature range of each part ...
Page 2
... Pin Configuration and Function Descriptions ............................. 6 Typical Performance Characteristics ............................................. 7 Theory of Operation ...................................................................... 11 REVISION HISTORY 7/10—Revision 0: Initial Version Thermocouples ........................................................................... 11 Thermocouple Signal Conditioner .......................................... 11 AD8494/AD8495/AD8496/AD8497 Architecture .................. 11 Maximum Error Calculation .................................................... 12 Recommendations for Best Circuit Performance .................. 13 Applications Information .............................................................. 14 Basic Connection ....................................................................... 14 ...
Page 3
... Output Voltage Range 5 Short-Circuit Current DYNAMIC RESPONSE −3 dB Bandwidth AD8494 AD8495/AD8497 AD8496 Settling Time to 0. output step AD8494 AD8495/AD8497 AD8496 POWER SUPPLY 6 Operating Voltage Range Single Supply Dual Supply Quiescent Current = 25° 100 kΩ, unless otherwise noted. Specifications do not include ...
Page 4
... With a 100 kΩ load, measurement junction temperatures beyond approximately 880°C for the AD8494 and AD8496 and beyond approximately 960°C for the AD8495 and AD8497 require supply voltages larger than negative voltage applied to the reference pin. Measurement junction temperatures below 5°C require either a positive offset voltage applied to the reference pin or a negative supply ...
Page 5
... JEDEC PCB in free air. Rating JA ±18 V Table 4. +V – Package – 8-Lead MSOP (RM-8) ±V S Indefinite −65°C to +150°C ESD CAUTION −40°C to +125°C 140°C 4.5 kV 1.5 kV Rev Page AD8494/AD8495/AD8496/AD8497 θ JA 135 Unit °C/W ...
Page 6
... AD8494/AD8495/AD8496/AD8497 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 5. Pin Function Descriptions Pin No. Mnemonic Description 1 −IN Negative Input. 2 REF Reference. This pin must be driven by low impedance. 3 −V Negative Supply Connect. 5 SENSE Sense Pin. In measurement mode, connect to output; in setpoint mode, connect to setpoint voltage. ...
Page 7
... Figure 7. Input Common-Mode Voltage Range vs. Output Voltage 100k 1M Figure 8. Input Bias Current and Input Offset Current vs. Temperature Rev Page AD8494/AD8495/AD8496/AD8497 1200 1000 CONNECTED THERMOCOUPLE 800 600 400 200 OPEN THERMOCOUPLE 0 THERMOCOUPLE CONNECTION AD849x OUTPUT –200 TIME (50µ ...
Page 8
... V (Gain = 96.7) Figure 12. AD8494 Input Overvoltage Performance 2. 1.50 8 1.00 4 0.50 0 –4 0 –8 –0.50 –12 –1.00 – –30 Figure 13. AD8495/AD8497 Input Overvoltage Performance, 2. 1.50 8 1.00 4 0.50 0 –4 0 –8 –0.50 –12 –1.00 – –30 = 2.7 V Figure 14. AD8496 Input Overvoltage Performance Rev Page ...
Page 9
... Figure 15. AD8494/AD8496 Small-Signal Response with Various Capacitive Loads 120µs/DIV Figure 16. Small-Signal Response 100 kΩ 2V/DIV SETTLING TO 0.1% IN 40µs 0.02%/DIV 100µs/DIV Figure 17. AD8495/AD8497 Large-Signal Step Response and Settling Time C = 0pF 1000pF 4700pF L C ...
Page 10
... AD8494/AD8495/AD8496/AD8497 1s/DIV Figure 21. 0 RTI Voltage Noise –1 –2 –3 –4 –5 1k 10k LOAD RESISTANCE (Ω) Figure 22. Output Voltage Swing vs. Load Resistance, V 100 100 FREQUENCY (Hz) Figure 23. Voltage Noise Spectral Density vs. Frequency (+) –40°C (+) +25° ...
Page 11
... The AD8494 and AD8496 (J type) have an instrumentation amplifier with a gain of 96.7 and 90.35, respectively. • The AD8495 and AD8497 (K type) have an instrumentation amplifier with a gain of 122.4. Rev Page AD8494/AD8495/AD8496/AD8497 Reference Junction ...
Page 12
... AD8497 K ±2°C For temperature ranges outside those listed in Table 7 or for instructions on how to correct for thermocouple nonlinearity error with software, see the product page for the AD8494, AD8495, AD8496, or AD8497, or contact an Analog Devices representative. Rev Page Ambient Measurement Temperature ...
Page 13
... If the ambient temperature sensor configuration is working correctly, the problem typically lies with how the thermocouple is connected to the AD849x. Common errors include an incorrect grounding configuration or lack of filtering. Rev Page AD8494/AD8495/AD8496/AD8497 KEEP JUNCTION AND AD849x AT SAME MEASUREMENT REFERENCE JUNCTION ...
Page 14
... The AD8494 is the best choice for use as an ambient temper- ature sensor. The AD8495, AD8496, and AD8497 can also be configured as ambient temperature sensors, but their output transfer functions are not precisely 5 mV/°C. For information about the exact transfer functions of the AD8494/AD8495/ AD8496/AD8497, see the product page for the AD8494, , also ...
Page 15
... The reference pin can also be used to offset any initial calibra- S tion errors. Apply a small reference voltage proportional to the error to nullify the effect of the calibration error on the output OUT SENSE 1kΩ SETPOINT VOLTAGE S Rev Page AD8494/AD8495/AD8496/AD8497 × 5 mV/° OUT MJ REF ) on S indicates REF ...
Page 16
... AD8497ARMZ 25°C to 100°C AD8497ARMZ-R7 25°C to 100°C AD8497CRMZ 25°C to 100°C AD8497CRMZ-R7 25°C to 100° RoHS Compliant Part. 2 The AD8494 and AD8496 models are prereleased. ©2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. ...