Part A
AD8497ARMZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 6084 個数
- Package
- MSOP-8
- Series
- インターフェース - センサーおよび検出器インターフェース
Replacement verdict
Compatible functional replacement candidate
The AD8497ARMZ and AD8494CRMZ are both thermocouple amplifiers from the same AD849x family, sharing identical functionality, supply requirements, and output characteristics. The primary distinction lies in their factory-set thermocouple calibration and specified temperature range, meaning the AD8497ARMZ can serve as a functional substitute for the AD8494CRMZ only when the application's thermocouple type and operating temperature profile align with the AD8497's calibration. Designers should confirm thermocouple compatibility and verify the narrower specified temperature range before adopting the AD8497ARMZ as a replacement.
Function and Output Type
High match
Supply Voltage Range
High match
Thermocouple Calibration
Validation required
Operating Temperature Range
Validation required
Parts at a glance
Part B
AD8494CRMZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 7989 個数
- Package
- TSSOP-8
- Series
- インターフェース - センサーおよび検出器インターフェース
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 | AD8494CRMZ | 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. |
| Temperature Range | 0°C to +500°C | 0°C to +1000°C | Defines the usable measurement span; the K-type version supports much higher temperatures than the J-type version. |
| Output Voltage at 25°C | 2.5 V | 2.5 V | Sets the zero-point reference of the analog output, which must match the ADC input range for correct digitization. |
| Output Scale Factor | 5 mV/°C | 5 mV/°C | Determines the sensitivity of the output; identical scaling simplifies interchangeability of downstream signal conditioning. |
| Supply Voltage Range | 2.7 V to 18 V | 2.7 V to 18 V | Must be compatible with the system power rail; both parts share the same wide supply range. |
| Supply Current | 180 µA (typical) | 180 µA (typical) | Affects power budget in low-power and battery-operated designs; both are equally low-power. |
| Package | 8-Lead MSOP (RM) | 8-Lead MSOP (RM) | Footprint and assembly compatibility; identical package allows drop-in PCB replacement. |
| Operating Temperature Range | −40°C to +125°C | −40°C to +125°C | Defines the ambient conditions the IC itself can withstand; identical ratings mean equal environmental robustness. |
| Cold Junction Compensation | On-chip | On-chip | Integrated CJC eliminates external compensation circuitry; both parts include it, simplifying design. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8497ARMZ | AD8494CRMZ |
|---|---|---|
| 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 primary functional differences between the AD8497ARMZ and the AD8494CRMZ?
Both devices are thermocouple amplifiers with a built-in cold junction compensation (CJC) sensor, but they are calibrated for different thermocouple types. The AD8497ARMZ is factory-trimmed for a K-type thermocouple (5 mV/°C nominal output slope), while the AD8494CRMZ is trimmed for a J-type thermocouple (also 5 mV/°C nominal output slope). The AD8497ARMZ is specified over a wider ambient temperature range of −40°C to +125°C, whereas the AD8494CRMZ is specified over 0°C to +50°C.
Are the AD8497ARMZ and AD8494CRMZ pin-compatible and package-compatible?
Yes. Both parts are offered in an 8-lead MSOP (RM) package with the same pinout, so they are footprint-compatible. However, because they are calibrated for different thermocouple types, they are not electrically interchangeable without re-validating the thermocouple type and output scaling in the target design.
What is the output voltage slope of each device?
Both the AD8497ARMZ and AD8494CRMZ provide a nominal output slope of 5 mV/°C, which allows direct reading by an ADC without additional gain stages. The slope is factory-trimmed for the respective thermocouple type (K-type for the AD8497ARMZ, J-type for the AD8494CRMZ).
What supply voltage range do these thermocouple amplifiers require?
Both devices operate from a single supply of 2.7 V to 18 V, or from dual supplies of ±2.7 V to ±18 V, per the manufacturer datasheet. This flexibility supports both battery-powered and industrial signal-chain designs.
How do the operating temperature ranges of the two parts compare?
The AD8497ARMZ is specified for operation from −40°C to +125°C, making it suitable for wider industrial ambient conditions. The AD8494CRMZ is specified for 0°C to +50°C, which is appropriate for benchtop or controlled-environment applications.
Do these devices include cold junction compensation?
Yes. Both the AD8497ARMZ and AD8494CRMZ integrate a cold junction compensation sensor and signal conditioning on-chip, so no external CJC circuit is required. The CJC is trimmed for the corresponding thermocouple type of each part.
Can the AD8497ARMZ be used with a J-type thermocouple or the AD8494CRMZ with a K-type thermocouple?
No, not without recalibration. Each device is factory-trimmed for its specific thermocouple type (K-type for the AD8497ARMZ, J-type for the AD8494CRMZ). Using the wrong thermocouple type will produce an incorrect temperature reading because the CJC and transfer function are matched to the intended thermocouple.
What is the typical quiescent supply current of these amplifiers?
Per the manufacturer datasheet, both the AD8497ARMZ and AD8494CRMZ draw a typical quiescent supply current of approximately 180 µA, which is suitable for low-power portable and remote-sensing applications.