Overview
The LM335AZT is a precision temperature sensor produced by STMicroelectronics. It operates as a 2-terminal Zener diode, with the breakdown voltage directly proportional to the absolute temperature at a rate of 10mV/°K. This sensor is part of the LM135, LM235, and LM335 family, known for their high accuracy and ease of calibration. The LM335AZT is calibrated at +25°C and offers a typical error of less than 1°C over a 100°C temperature range, making it suitable for a variety of temperature sensing applications.
Key Specifications
| Parameter | Unit | Min. | Typ. | Max. |
|---|---|---|---|---|
| Operating Temperature Range | °C | -40 | +100 | |
| Operating Output Voltage at Tcase = +25°C, IR = 1mA | V | 2.92 | 2.98 | 3.04 |
| Uncalibrated Temperature Error (IR = 1mA) | °C | 1 | 2 | 5 |
| Calibrated Error at Extended Temperature (Tcase = Tmax, Intermittent) | °C | 2 | ||
| Dynamic Impedance (IR = 1mA) | Ω | 0.5 | 0.6 | |
| Output Voltage Temperature Drift | mV/°C | +10 | ||
| Operating Current Range | mA | 0.45 | 5 |
Key Features
- Direct Calibration in °K: The LM335AZT is directly calibrated in Kelvin, making it easy to use in temperature sensing applications.
- High Accuracy: Offers a typical error of less than 1°C over a 100°C temperature range.
- Low Dynamic Impedance: Less than 1Ω, ensuring minimal impact on the circuit.
- Wide Operating Current Range: Operates from 450µA to 5mA without altering its characteristics.
- Linear Output: The output voltage is linearly proportional to the absolute temperature.
- Easy Calibration: Can be easily calibrated for higher accuracies using a single-point calibration method.
Applications
- Basic Temperature Sensing: Used in simple temperature sensing circuits.
- Calibrated Sensors: Can be calibrated for specific temperature ranges and applications.
- Average Temperature Sensing: Useful in applications requiring the average temperature of multiple points.
- Temperature Controllers: Can be used in temperature control circuits to maintain a specific temperature.
- Thermocouple Cold Junction Compensation: Used to compensate for temperature variations in thermocouple measurements.
- Differential Temperature Sensing: Can measure the difference in temperature between two points.
Q & A
- What is the operating temperature range of the LM335AZT?
The LM335AZT operates within a temperature range of -40°C to +100°C.
- How is the output voltage of the LM335AZT related to temperature?
The output voltage is directly proportional to the absolute temperature at a rate of 10mV/°K.
- What is the typical error of the LM335AZT over a 100°C temperature range?
The typical error is less than 1°C over a 100°C temperature range.
- What is the dynamic impedance of the LM335AZT?
The dynamic impedance is less than 1Ω.
- What is the operating current range of the LM335AZT?
The LM335AZT operates within a current range of 450µA to 5mA.
- How can the LM335AZT be calibrated for higher accuracies?
The LM335AZT can be easily calibrated using a single-point calibration method.
- What are some common applications of the LM335AZT?
Common applications include basic temperature sensing, calibrated sensors, average temperature sensing, temperature controllers, thermocouple cold junction compensation, and differential temperature sensing.
- What package types are available for the LM335AZT?
The LM335AZT is available in TO-92 and SO-8 packages.
- Is the LM335AZT RoHS compliant?
Yes, the LM335AZT is RoHS compliant and comes in ECOPACK® packages.
- What precautions should be taken to ensure good sensing accuracy with the LM335AZT?
Precautions include ensuring low current operation to minimize self-heating and using a temperature-stable current source.
