What Is an Isolation Amplifier?
Isolation amplifier is a special measurement amplifier circuit. There is no direct circuit coupling between its input, output and power circuit, that is, the signal has no common ground terminal during transmission. There is an ohmically isolated device between the input circuit and the amplifier output [1] .
- Chinese name
- Isolation amplifier
- Accuracy class
- 0.1 grade, 0.2 grade
- Single power supply
- 5VDC, 12VDC
- input signal
- 0-2.5V / 0-5V / 0-10V
- Isolation amplifier is a special measurement amplifier circuit. There is no direct circuit coupling between its input, output and power circuit, that is, the signal has no common ground terminal during transmission. There is an ohmically isolated device between the input circuit and the amplifier output [1] .
- It performs various signals such as voltage and current, AC alternating current, 4-20mA, 0-5V, mV millivolt, PWM pulse, Hz frequency, Pt100 thermal resistance, sine wave, square wave, potentiometer, speed, etc. in the automatic control system. The integrated circuit for transmission, conversion, isolation, amplification, and remote transmission can be used with various industrial sensors to meet the user's needs for local monitoring and remote data collection.
Isolation amplifier definition
- Isolation amplifier (IC package, one-in-one-out rail, one-in-two-out rail, two-in-two-out rail) is used for voltage and current, AC AC, 4-20mA, 0-5V, mV millivolt, PWM in the automation control system. Integrated circuits for transmitting, converting, isolating, amplifying, and remotely transmitting various signals such as pulses, Hz frequency, Pt100 thermal resistance, sine wave, square wave, potentiometer, and speed, which can be used with various industrial sensors to meet users The need to monitor remote data collection locally. Widely used in railway transportation, machinery, electrical, telecommunications, electric power, petroleum, chemical, steel, sewage treatment, building construction and other fields of data acquisition, signal transmission conversion, PLC, DCS and other industrial measurement and control systems to improve and supplement I / O plug-in function, increase system applicability and reliability of the field environment.
- Accuracy grade: 0.1 grade, 0.2 grade.
- Single power supply: 5VDC, 12VDC, 15VDC, 24VDC or custom single power supply
- Input signal: 0-2.5V / 0-5V / 0-10V / 1-5V / 2-10V / 0- ± 5V / 0- ± 10V / equal voltage signal and 0-1mA / 0-10mA / 0-20mA / 4-20mA / 0- ± 1mA / 0- ± 10mA / 0- ± 20mA / 0-5AAC / 0-220AAC / 50Hz-99Hz / 100Hz-99KHz / 0-1KHz / 0-5KHz / 0-50 / 0- 1000 / 200mV-50V / etc. Signal
- Output signal 0-75mV / 0-2.5V / 0-5V / 0-10V / 1-5V / 2-10V / 0- ± 5V / 0- ± 10V / 0- ± 100mV and other standard voltage signals and 0-1mA / 0-10mA / 0-20mA / 4-20mA and other standard current signals, with high load capacity.
- Extremely high linearity in the full range (non-linearity <0.1%)
Isolation amplifier use
- Isolation amplifiers are used to protect data acquisition devices from potentially damaging voltages from remote sensors. These amplifiers are also used to amplify low-level signals in multi-channel applications. They also eliminate measurement errors caused by ground loops. Since no additional isolated power supply is needed, an isolation amplifier with an internal transformer can reduce circuit costs [1] .
Isolation amplifier composition
- It consists of an instrumentation amplifier (or op amp) and a unity gain isolation stage. The unity-gain isolation stage completely isolates the input and output of the device (ohmic isolation), making the electrical signal without ohmic continuity.
- Instrumentation Amplifier + Isolation Circuit === Isolated Instrumentation Amplifier
- Op Amp + Isolation Circuit === Isolation Amplifier
Isolation amplifier ideal characteristics
- The ideal isolation amplifier requires that the electrical signal has no ohmic continuity at all, the transmitted signal requires no attenuation, and the signal source does not have to be grounded.
Application field of isolation amplifier
- The excellent input-output ohmic isolation characteristics of the isolation amplifier make it suitable for use as an interface between medical monitoring instruments and patients. The high isolation level and extremely low leakage current play an important role in protecting electronic instruments. Power test equipment. (Isolate the high voltage part and the weak current part). Protect the safety of people and equipment.
- It is mainly used in portable measuring instruments and some measurement systems, and can transmit signals with high impedance and high common mode rejection in a noisy environment.
- It is used in biomedical measurement to ensure that the human body is not harmed by leakage current and high voltage (up to hundreds of volts and thousands of volts) above 10uA.
- It is used in industry to prevent grid voltage from causing damage to low-voltage signal circuits (including computers) due to faults [1] .
Isolation amplifier classification
- Classification by isolation mode:
- Two-port isolation: refers to the ohmic isolation between the signal input part and the signal output part. Take other measures to isolate the power.
- Three-port isolation: refers to the three parts of the input, output, and power supply sections being ohmically isolated from each other.
- Classification by isolation method:
- Photoelectric isolation
- Capacitive isolation
- Transformer [1] voltage isolation (electromagnetic isolation)
Isolation amplifier model and description
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| ||
|
|
|
|
Isolation amplifier product application
- Passive sensor isolated power distribution and signal acquisition and transmission Preamplifier, bridge and other circuit configuration power supply for convenient signal collection PLC, DCS on-site analog signal isolation and acquisition DC current / voltage signal isolation, conversion and amplification Analog signal Ground line interference suppression and data isolation and acquisition Isolation and long-distance transmission of industrial field signals Receiving and receiving signals of instruments and sensors Isolation safety barrier for power monitoring and medical equipment
Isolation amplifier selection example
- Example 1: Input 1: 0-5V auxiliary power: 24V output 2: 4-20mA
- Example 2: input signal: 4-20mA; output signal: 4-20mA; auxiliary power: 24VDC;
Product model: ISOEMA4-P1-O1 Deng 1530271 Rong 8208