AD590 Temperature Sensor: Datasheet, Circuit and Alternative

The AD590 is a precision temperature sensor widely used in various industrial, scientific, and consumer applications. Known for its accuracy and stability, the AD590 provides an output voltage that is directly proportional to the temperature being measured. With its simple two-wire interface and wide temperature range, the AD590 offers versatility and reliability in temperature sensing.

In this article, we will explore the key features and specifications of the AD590 temperature sensor, discuss its circuit implementation, and provide alternatives for applications that require temperature sensing capabilities.

What is AD590 Temperature Sensor

The AD590 is a type of temperature sensor manufactured by Analog Devices Inc., a leading semiconductor company. The AD590 is specifically designed as a two-terminal integrated circuit (IC) temperature transducer. It operates on the principle of converting temperature changes into proportional voltage output.

AD590 Features

1. The current flowing through the device (μA) is equal to the thermodynamic temperature (Kelvin) degrees of the environment in which the device is located, i.e.: IT/T = 1μA / K. In the formula: IT - current flowing through the device (AD590), unit μA. T - thermodynamic temperature, unit K.

2. The temperature measurement range of AD590 is -55℃- +150℃.

3. AD590 supply voltage range of 4V-30V. supply voltage can be varied in the range of 4V-6V, current IT change 1μA, equivalent to a temperature change of 1K. AD590 can withstand 44V forward voltage and 20V reverse voltage, so the device will not be damaged by reverse connection.

4. The output resistance is 710MΩ.

5. High precision. AD590 has a total of I, J, K, L, M five grades, of which M grade precision is the highest, in the -55 ℃ ~ +150 ℃ range, non-linear error ± 0.3 ℃.

AD590 Pinout

AD590 CAD Model

AD590 Specifications

AD590 Working Principle

When the measured temperature is certain, the AD590 is equivalent to a constant current source, connect it to a DC power supply of 5-30V and connect a 1kΩ constant value resistor in series with the output, then the current flowing through this resistor will be proportional to the measured temperature, and there will be a voltage signal of 1mV/K at both ends of the resistor. The basic circuit is shown below.

AD590 Application Circuit

The following figure shows the basic application circuit of the AD590 for thermodynamic temperature measurement. Since the current flowing through the AD590 is proportional to the thermodynamic temperature, when the sum of the resistance of resistor R1 and potentiometer R2 is 1kΩ, the output voltage V0 varies with temperature by 1mV/K.

However, since the gain of AD590 has deviation and the resistance also has deviation, the circuit should be adjusted by putting AD590 in the ice and water mixture and adjusting potentiometer R2 so that V0=273.2+25=298.2 (mV). However, this adjustment only ensures a high accuracy near 0℃ or 25℃.

AD590 Advantages and Disadvantages

1. Advantages of the AD590 temperature sensor:

• Wide Temperature Range: The AD590 is capable of measuring temperatures within a wide range, typically from -55°C to +150°C. This makes it suitable for various applications that require temperature sensing in extreme environments.
• Proportional Voltage Output: It provides an output voltage that is directly proportional to the temperature being measured. This linear relationship simplifies temperature-to-voltage conversion and facilitates easy integration into measurement systems.
• Factory Calibrated: It is factory calibrated, eliminating the need for additional calibration procedures during normal usage. This saves time and effort in implementing the sensor in applications.
• Low Power Consumption: It operates on low power consumption, typically in the range of a few milliwatts. This makes it suitable for battery-operated or energy-efficient applications.
• High Accuracy: It offers high accuracy in temperature measurements, typically with an error of less than 1°C. This accuracy is crucial in applications where precise temperature control or monitoring is required.

2. Disadvantages of the AD590 temperature sensor:

• Nonlinear Output: The AD590 has a nonlinear output, meaning the voltage does not change linearly with temperature. Additional circuitry or calibration may be required to achieve a linear response if necessary for a specific application.
• Limited Packaging Options: It is typically available in a two-terminal TO-52 package. This may limit the options for mounting or integration in certain systems or designs.
• Limited Temperature Range in Some Variations: While the typical temperature range of the AD590 is -55°C to +150°C, it's important to note that some variations or models may have different temperature ranges. It is essential to check the specifications for the specific variant being used.
• External Components Required: In most applications, the AD590 requires additional external components, such as a power supply, signal conditioning circuitry, and possibly linearization circuitry, depending on the desired output response.

AD590 Alternatives

Here are AD590 alternatives for reference,

AD590 vs LM35: Which is Better

The choice between the AD590 and LM35 temperature sensors depends on the specific requirements and constraints of your application. Both sensors have their advantages and may be more suitable in different scenarios. Here are some factors to consider when determining which sensor is better for your application:

AD590 Datasheet PDF

Free download AD590 datasheet pdf here>>

Conclusion

In conclusion, the AD590 temperature sensor is a versatile and reliable component for precise temperature measurement in various applications. Its accuracy, stability, and wide temperature range make it suitable for industrial, scientific, and consumer applications. By referring to the datasheet and understanding the recommended circuit implementation, you can leverage the full potential of the AD590 temperature sensor in your projects.

Additionally, alternative temperature sensing options are available for specific requirements or when the AD590 may not be the optimal choice. Whether you are designing a temperature control system, monitoring environmental conditions, or implementing thermal protection measures, the AD590 and its alternatives offer valuable solutions for accurate and reliable temperature sensing.