Abstract：Isolation amplifier is a specialized measurement amplification circuit in which there is no direct electrical coupling between the input, output, and power supply circuits. This means the signal lacks a common ground during transmission, and an electrically isolated device exists between the input circuit and the amplifier output.

Definition：sunyuansz Isolation amplifiers (available with PCB direct-soldered packaging; DIN35 rail-mounted options include 1-in&1-out, 1-in&2-out, 2-in&2-out, and 4-in&4-out etc) are integrated modules used in automation control systems to transmit, convert, isolate, amplify, and remotely transmit signals from various sensor transmitters, including 4-20mA, 0-5V, AC, mV, PWM pulse width modulation, Hz frequency, Pt100 thermistors, sine waves, square waves, potentiometers, and rotational speed .It can be used in conjunction with various industrial instruments and sensors to meet the measurement and control requirements of industrial field control systems, as well as remote data acquisition needs.

一、The Importance of Signal Isolators

1. Enhance signal stability and reliability

Signal isolators significantly reduce the adverse effects of external electromagnetic interference and radio frequency interference on measurement environments and control signals, thereby enhancing signal stability and reliability,through isolation and signal processing, ensure signal integrity and equipment safety.

2. Achieve signal conversion and matching

Signal isolators resolve signal mismatch issues by converting and matching signals of different types or levels. This ensures seamless signal transmission and interaction between diverse devices while compensating for signal attenuation over long distances. They enable high-precision isolated transmission and distribution of analog signals in configurations such as one-to-two, one-to-four, or one-to-multiple outputs, powering multiple devices.

3.  Ensure system security

Protect personnel and equipment safety, prevent high-voltage intrusion, suppress transient pulse interference, and avoid equipment damage. By isolating hazardous high-voltage or high-current signals, signal isolators effectively safeguard personnel and equipment, ensuring stable system operation.

4.  Segmented Grounding Loop

Electrical Isolation: Disconnecting the direct electrical connection between the signal source and the receiving equipment, and separating ground loops to prevent circulating current interference between different power grounding points at the site, thereby ensuring signal accuracy.

5Signal Isolation Conversion and Adaptation

Convert signal types (e.g., 4-20mA to 0-10V) to resolve impedance mismatch issues and ensure stable signal transmission.

6. Establish a protection control system

To ensure the control system maintains stable operation when encountering abnormal input signals and to reduce the risk of failure, we must establish a comprehensive protection control system. This will significantly enhance the overall stability and reliability of the entire system.

7.  Streamline the troubleshooting process

When system failures occur, isolators enable us to swiftly and accurately determine whether the fault lies at the input or output end, thereby efficiently completing troubleshooting and repair tasks.

二、Typical Application Scenarios

Industrial Automation Control:  Used for signal transmission in instrumentation, sensors, and transmitters to eliminate interference.

On-site Data Acquisition System: Isolated Signals to Ensure Data Accuracy。

PLC and DCS Systems: Prevent signal interference to ensure stable system operation.

三、Product Features and Selection Recommendations

Product Features

Accuracy Class: 0.1, 0.2, 0.5.

Power Supply: 5VDC, 12VDC, 15VDC, 24VDC, or custom single-power-supply configuration.

Input signal：0-75mV/0-2.5V/0-5V/0-10V/1-5V/2-10V/0-±5V/0-±10V/0-±100mV etc Standard voltage signal

0-1mA/0-10mA/0-20mA/4-20mA/0-±1mA/0-±10mA/0-±20mA etc Standard current signal；

0-1VAC/0-10VAC/0-220VAC/0-500VAC/0-1AAC/0-5AAC/0-10AAC/0-1VRMS etc AC voltage and current signals ；0-1KHZ/0-5KHZ/0-10KHZ etc Frequency signal or PWM pulse width signal；

0-50Ω/0-1KΩ/0-5KΩ/0-10KΩ etc Equivalent displacement resistance signal；

PT100/PT1000/CU50 etc Resistance temperature detector signal；

±200mV～±50V Rotational speed sine wave and other signals。

Output signal：0-75mV/0-2.5V/0-5V/0-10V/1-5V/2-10V/0-±5V/0-±10V/0-±100mV etc Standard voltage signal；

0-1mA /0-10mA/0-20mA/ 4-20mA/0-20±mA etc Standard current signal with high load capacity；

0-1KHZ/0-5KHZ/0-10KHZ etc Square wave frequency signal or PWM Pulse width signal；

Exceptionally high linearity across the entire measurement range (nonlinearity ≤ 0.1%)

Model Selection Recommendations

photo-electric Isolated Amplifier（ISO U/A-P-O series）

Magneto-electric Isolation Amplifier（ISOEM U/A-P-O series；ISOEM210 series）

Capacitive Isolation Amplifier（ISOC124P ；ISOEC U/A-P-O series）

Small-Signal Isolated Amplifier（ISOEM-U/A-P-O-SD series）

Displacement Signal Isolation Transmitter（SY/ISO R-P-O series）

True RMS Signal Isolation Amplifier(ISO RMS-P-O series）

Single-Phase AC Signal Isolation Amplifier（ISO AC-P-O series）

Non-isolated DC Signal Transmitter (SY-U/A-P-O series)

Thermoresistor Signal Isolation Transmitter (ISO Z-W-P-O series）

Frequency-to-Voltage-Current Transducer (ISO F-P-O series）

Voltage and Current to Frequency Transmitter (ISO U/A-P-F series)

Speed Signal Isolation Transmitter (ISO S-P-O series）

Passive ISO 4-20mA Series Isolated Transmitters

High/Low Selection Signal Isolation Transmitter（ISO C-P-O-S series）

PWM Pulse Width Modulation Signal Isolated Transmitter (ISO D-P-O-Q Series, ISO D-O1 Series)

四、Summary

Select isolation amplifiers with different signals, types, characteristics, and parameters based on the industrial field environment to enhance and supplement I/O module functionality, thereby increasing system adaptability and reliability in the field environment.

Isolation amplifiers currently serve as critical electronic components for industrial fieldbus systems, PLC/DCS, and Ethernet IoT remote intelligent control devices in applications such as smart sensors, AI servers, rail transit, unmanned equipment, electric vehicles, smart grid upgrades, wind/solar power generation, and nuclear power generation. They find extensive use across industries including industrial automation, robotics, unmanned naval vessels and drones, measurement and control, environmental protection and chemical engineering, instrumentation, medical equipment, automotive electronics, security surveillance, broadcasting instruments, and military equipment.