The instrumentation amplifier module with AD620 as the core realizes differential amplification, single-ended ground-to-ground signal amplification, and AC weak signal amplification, which is convenient for single-chip microcomputer and PLC acquisition and analysis!
Features: (suitable for millivolt MV level differential amplification)
1>.AD620 is not a rail-to-rail input and output op amp, that is to say, with 5V power supply, the maximum output voltage is basically equal to 3.5V, AD620 is a common chip of high-precision instrumentation amplifier, it is a military-grade chip, which is more in the instrumentation amplifier circuit. Commonly used.
2>.AD620's offset voltage is lower than the offset voltage of LM358, can effectively amplify the MV level signal as much as possible, especially the sensor with a small output voltage range (such as: 0-5MV can't be changed with LM358)
1>.the power supply voltage:
If the 3-5V single-supply DC power supply (please connect the power supply to the low-voltage port to supply power to the board)
If the 6-24V single-supply DC power supply (please connect the power supply to the wide voltage port to supply power to the board)
Current output: maximum 15-20MA
2>.input signal: front-end sensor analog signal introduction
2.1>.If the sensor or signal line (excluding the power supply and ground) has only one signal line, then it is a single-ended ground signal amplification, you can directly connect the signal line to B+, G to the common ground, and at the same time A – Shorted with G.
2.2>.If the sensor is a weighing or pressure strain gauge, the signal line is two, one is the signal is positive, the signal is negative, please connect the sensor output signal positive pin to INB, the signal negative reference The pin is connected to the INA, and the differential amplification is realized after zero adjustment.
About zeroing:Short-circuit A- and B+, then adjust the output to 0V by zeroing the potentiometer
3>.output signal: The AD620AD620 is a low cost, high precision instrumentation amplifier that requires only one external resistor to set the gain from 1 to 10,000. The larger the gain, the larger the error will be. Please adjust the potentiometer according to the actual needs, so that the output is suitable for the requirements.
With high accuracy (40 ppm maximum nonlinearity), low offset voltage (up to 50 uV) and low offset drift (maximum 0.6 uV/℃), the AD620 is ideal for precision data acquisition systems such as electronic scales and sensor interfaces. . It also features low noise, low input bias current, and low power consumption, making it ideal for medical applications such as ECG and non-invasive blood pressure monitors.It can amplify the signal of millivolts or even weaker. If the gain requirement is relatively high, according to the actual situation, it can be amplified by the first step after the amplification module.