Power and Signal Isolation Amplifiers - Which One Works for You?
Isolation amplifiers are a type of differential amplifier. They are used to amplify weak signals, and to provide electrical isolation between two circuits. The isolation amplifiers are essential in any system where electrical connections between circuits need to be isolated. There are two types of isolation amplifiers - power isolation amplifiers and signal isolation amplifiers.
Power Isolation Amplifiers
Power isolation amplifiers are intended to isolate high-voltage power supply lines in control systems, such as motor control systems or AC line-monitoring systems.
These amplifiers use transformers or capacitors to achieve isolation. Power isolation amplifiers require a high level of isolation voltage of at least 1,500 volts. They can also tolerate high common-mode voltage, up to 2 kV, without affecting the measurement accuracy.
Signal Isolation Amplifiers
Signal isolation amplifiers or current/voltage isolators are intended for applications where analog signals need to be transmitted across a small distance or isolated from ground noise, typically DC voltage sensing, industrial process control, and medical equipment.
These amplifiers are designed to block any DC voltage between the input and the output, as well as any common-mode voltage. Signal isolation amplifiers can achieve high isolation of up to 5 kV and can operate at frequencies ranging from DC to a few tens of kHz.
Comparison
Power isolation amplifiers and signal isolation amplifiers are both useful for electrical isolation. In some applications, power isolation amplifiers are more practical, while in others, signal isolation amplifiers are the better option.
Power isolation amplifiers are good for high-voltage applications such as motor control or power systems. Using power isolation amplifiers protects sensitive electronic circuits from exposure to high-voltage power, preventing damage to the circuitry.
On the other hand, signal isolation amplifiers are good for analog signal transmission in areas with high magnetic fields, radio frequency noise, or other types of electrical interference. They can help protect low-level signals from interference generated by power or radio signals, ensuring better signal quality.
It is important to consider the specific requirements of each application to determine which type of isolation amplifier is appropriate.
Conclusion
Isolation amplifiers are an essential component of control and measurement systems where electrical connections require isolation. Power isolation amplifiers and signal isolation amplifiers are both important in different applications.
When selecting an isolation amplifier, it is important to consider the specific requirements of each application before making a decision.
References:
- Analog Devices, Inc. (2019). Isolation Amplifiers. Retrieved June 16, 2021 from https://www.analog.com/en/products/amplifiers/isolation-amplifiers.html
- Texas Instruments (2021). What is an Isolation Amplifier? Retrieved June 16, 2021 from https://www.ti.com/amplifier-circuit/isolation-amplifier/overview.html.