Part A
AD8497ARMZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6084 PCS
- Package
- MSOP-8
- Series
- Interface - Sensor and Detector Interfaces
Replacement verdict
Compatible functional replacement candidate
The AD8497ARMZ and AD8494ARMZ are both thermocouple amplifier ICs from the same AD849x family in identical 8-lead MSOP packages, sharing the same supply range, output configuration, and pinout. They differ primarily in their factory-set thermocouple type and corresponding temperature range, so the AD8497ARMZ can serve as a functional substitute for the AD8494ARMZ only when the application's thermocouple type and measurement range align with the AD8497's calibration.
Package Type
High match
Output Type
High match
Thermocouple Type
Validation required
Temperature Range
Validation required
Parts at a glance
Part B
AD8494ARMZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 9077 PCS
- Package
- TSSOP-8
- Series
- Interface - Sensor and Detector Interfaces
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8497ARMZ | AD8494ARMZ | Why it matters |
|---|---|---|---|
| Sensor Type | J-Type Thermocouple | K-Type Thermocouple | Determines which thermocouple the amplifier is calibrated for; using the wrong type produces large temperature measurement errors. |
| Output Voltage at 25°C (Vout) | 5 mV/°C scaled for J-type (approx. 1.25 V at 25°C ambient reference) | 5 mV/°C scaled for K-type (approx. 1.25 V at 25°C ambient reference) | The output scaling must match the thermocouple curve so downstream ADCs interpret temperature correctly. |
| Thermocouple Sensitivity Range | Optimized for J-type (~50 µV/°C nominal) | Optimized for K-type (~41 µV/°C nominal) | Internal gain and cold-junction compensation are trimmed to the specific thermocouple's Seebeck coefficient. |
| Temperature Range (Measurement) | 0°C to +750°C (J-type range) | 0°C to +1200°C (K-type range) | Defines the usable measurement span; K-type supports higher temperatures than J-type. |
| Supply Voltage Range | 2.7 V to 18 V (single supply) | 2.7 V to 18 V (single supply) | Both parts share the same supply flexibility, so power design is interchangeable. |
| Supply Current | ~180 µA typical | ~180 µA typical | Low quiescent current suits battery-powered and low-power instrumentation in both cases. |
| Package | 8-Lead MSOP (RMZ) | 8-Lead MSOP (RMZ) | Identical footprint allows drop-in PCB replacement without layout changes. |
| Operating Temperature Range | −40°C to +125°C | −40°C to +125°C | Same industrial temperature rating means equivalent environmental robustness. |
| Output Type | Analog voltage (ratiometric to temperature) | Analog voltage (ratiometric to temperature) | Both provide a linear analog output, so the same ADC front-end can be reused. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8497ARMZ | AD8494ARMZ |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Active |
| Type | Thermocouple Amplifier | Thermocouple Amplifier |
| Input Type | Differential | Differential |
| Output Type | Analog | Analog |
| Supply Current | 250 µA | 250 µA |
| Operating Temperature | 25°C ~ 100°C | 0°C ~ 50°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the AD8497ARMZ and AD8494ARMZ?
Both are thermocouple amplifiers with cold junction compensation from Analog Devices, packaged in an 8-lead MSOP (RMZ). The AD8494 is factory-trimmed for a J-type thermocouple (0°C to 50°C reference, 5 mV/°C nominal output), while the AD8497 is factory-trimmed for a K-type thermocouple (25°C reference, 5 mV/°C nominal output).
What is the key difference between the AD8497ARMZ and AD8494ARMZ?
The primary difference is the thermocouple type and reference junction temperature they are trimmed for: the AD8494ARMZ is calibrated for J-type thermocouples with a 0°C reference, and the AD8497ARMZ is calibrated for K-type thermocouples with a 25°C reference. This affects the output voltage-to-temperature transfer function and the usable measurement range.
Can the AD8497ARMZ and AD8494ARMZ be used interchangeably?
No, they are not direct substitutes. Because each is trimmed for a different thermocouple type and reference junction temperature, swapping them changes the temperature-to-voltage mapping and introduces measurement error unless the system is recalibrated for the alternate device and thermocouple type.
What is the nominal output voltage scaling of these devices?
Both devices provide a nominal output sensitivity of 5 mV/°C. The absolute output voltage at a given temperature differs because the AD8494ARMZ uses a 0°C reference and the AD8497ARMZ uses a 25°C reference, so the output offset differs between the two parts.
Do the AD8497ARMZ and AD8494ARMZ share the same package and pinout?
Yes, both are offered in the same 8-lead MSOP package (suffix ARMZ) with the same pin functions, including the thermocouple inputs, reference, output, and supply pins. The package and pinout are common, but the internal trimming differs.
What supply voltage do the AD8497ARMZ and AD8494ARMZ require?
Both devices operate from a single supply over the 2.7 V to 18 V range (or split supplies within that total), as specified in the Analog Devices datasheet. The wide supply range supports both low-voltage and higher-voltage industrial signal chains.
Which device should be selected for a K-type versus J-type thermocouple design?
Select the AD8497ARMZ for K-type thermocouples and the AD8494ARMZ for J-type thermocouples. Matching the device trim to the thermocouple type preserves the factory calibration and avoids the need for external cold junction compensation or recalibration.