Part A
AD8495CRMZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5995 PCS
- Package
- MSOP-8
- Series
- Interface - Sensor and Detector Interfaces
Replacement verdict
Compatible functional replacement candidate
The AD8495CRMZ and AD8494ARMZ are both thermocouple amplifier ICs from the same Analog Devices AD849x family, sharing a common functional architecture and SOIC package format. However, they are calibrated for different thermocouple types and differ in temperature range and grade, so the AD8494ARMZ is a functional replacement candidate for the AD8495CRMZ only when the application's thermocouple type and operating range are validated against the target design requirements.
Thermocouple Type
Validation required
Temperature Range
Validation required
Package Type
High match
Grade and Accuracy
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 | AD8495CRMZ | AD8494ARMZ | Why it matters |
|---|---|---|---|
| Sensor Type | K-type thermocouple | J-type thermocouple | Determines which thermocouple alloy the amplifier's cold-junction compensation and gain are calibrated for; using the wrong type causes large temperature errors. |
| Output Voltage Range | 0 V to 5 V (single supply) | 0 V to 5 V (single supply) | Both are specified for single-supply 0–5 V output, but the internal gain scaling differs by thermocouple type, affecting the usable output span. |
| Nominal Gain | ~122.4 V/V (5 mV/°C) | ~122.4 V/V (5 mV/°C) | The gain sets the output sensitivity; both target 5 mV/°C, but the cold-junction compensation curve is matched to a different thermocouple type. |
| Cold-Junction Compensation | Optimized for K-type | Optimized for J-type | The on-chip compensation network must match the thermocouple's Seebeck characteristic; mismatch introduces systematic temperature offset. |
| Supply Voltage Range | 2.7 V to 18 V (single) / ±2.7 V to ±18 V (dual) | 2.7 V to 18 V (single) / ±2.7 V to ±18 V (dual) | Wide supply range allows flexible system design; both parts share the same supply capability, so this is not a differentiator. |
| Operating Temperature Range | −40 °C to +125 °C | −40 °C to +125 °C | Industrial temperature range supports harsh environments; identical for both parts. |
| Package | 8-Lead MSOP (RM) | 8-Lead MSOP (RM) | Same footprint and pinout enable drop-in board compatibility, but electrical compensation differs. |
| Input Offset Voltage | Low offset (precision amplifier) | Low offset (precision amplifier) | Offset directly translates to temperature measurement error; both are precision-grade, so offset is comparable. |
| Thermocouple Compatibility | K-type only | J-type only | Functional substitutability requires matching the thermocouple in the system; the two parts are not interchangeable without changing the sensor type. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8495CRMZ | 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 | 0°C ~ 50°C | 0°C ~ 50°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary functional differences between the AD8495CRMZ and AD8494ARMZ?
Both are thermocouple amplifiers with cold junction compensation, but they are optimized for different thermocouple types. The AD8495CRMZ is calibrated for Type K thermocouples with a nominal output of 5 mV/°C, while the AD8494ARMZ is calibrated for Type J thermocouples with a nominal output of 5 mV/°C. The AD8495CRMZ is specified over a 0°C to +50°C ambient temperature range, whereas the AD8494ARMZ is specified over a −40°C to +125°C ambient temperature range.
Are the AD8495CRMZ and AD8494ARMZ pin-compatible?
Yes. Both devices are offered in an 8-lead SOIC package with the same pinout, so they are pin-compatible. However, because they are calibrated for different thermocouple types, the surrounding circuit and firmware scaling must be adjusted accordingly.
Can the AD8495CRMZ and AD8494ARMZ be used interchangeably in an existing design?
Not directly without design validation. The AD8495CRMZ is calibrated for Type K thermocouples and the AD8494ARMZ for Type J thermocouples, so the measured temperature-to-voltage transfer function differs. Substitution requires verifying the thermocouple type, output scaling, and the ambient temperature range against the datasheet specifications for each part.
What supply voltage range do the AD8495CRMZ and AD8494ARMZ 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, as specified in the manufacturer datasheet. The actual usable range depends on the required output swing and thermocouple input range.
How does the operating temperature range differ between the two parts?
The AD8495CRMZ is specified for operation over a 0°C to +50°C ambient temperature range, while the AD8494ARMZ is specified over a −40°C to +125°C ambient temperature range. Designs requiring extended ambient operation should account for this difference.
Do both devices include cold junction compensation?
Yes. Both the AD8495CRMZ and AD8494ARMZ integrate cold junction compensation circuitry, eliminating the need for an external temperature sensor and compensation network. The compensation is calibrated for the respective thermocouple type of each device.
What is the output voltage sensitivity of each device?
Both the AD8495CRMZ and AD8494ARMZ provide a nominal output sensitivity of 5 mV/°C, referenced to the respective thermocouple type. The AD8495CRMZ is calibrated for Type K thermocouples and the AD8494ARMZ for Type J thermocouples.