Description
AD620 Instrumentation Amplifier Gain Adjustment CNC MCP41010 OP Amp Differential Amplifier DC Voltage Amplifier
Product Description
AD620/AD623 is a low-cost, high-precision instrumentation amplifier that only requires an external resistor to set the gain, and the gain range is 1 to 1,000. Very suitable for battery-powered and portable (or remote) applications. AD620 has high accuracy, low offset voltage and low offset drift characteristics. It is an ideal choice for precision data acquisition systems such as electronic scales and sensor interfaces. It also has low noise, low input bias current and low power consumption characteristics, making it very suitable for medical applications such as ECG and non-invasive blood pressure monitors. The module is powered by positive and negative power supplies, and the analog potentiometer is used to adjust the gain by default. It can be switched to the programmable digital potentiometer to adjust the gain through the jumper cap. Users can choose according to their own needs.
Specification
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Module model
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AD620
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Module type
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Weak signal amplifier
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Input signal form
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Single-ended or differential, Disconnect the SB5 jump point for differential input
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Input voltage range
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100uV-1Vpp
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Module supply voltage
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AD620 ±15V （max）/ AD623 ±6V （max）
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Module power supply current
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20mA
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Output voltage range
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AD620 ±13V (MAX),/ AD623 ±6V, The output is within the power supply
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Output current
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10mA (max)
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Module gain range
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AD620 1-10000 times / AD623 1-10000 times, adjustable slip
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Gain control method
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Program control/slip change, jumper cap switch
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Program Control Agreement
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SPI, 8-digit digital potentiometer
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Bias voltage adjustment range
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± 2V (MAX)
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Input offset voltage
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200uV (MAX)
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Input offset drift
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2uV/°C (MAX)
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Input bias current
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125nA (MAX)
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Common mode rejection ratio
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90dB (MIN, G = 10)
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Input voltage noise
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35nV Hz (1KHz)
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Module weight
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10g
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Module protection
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without
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Module weight
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16g
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Module specifications
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50*50*7mm, length * width * height-PCB size
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Module heating
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No heat sink, Excessive input voltage may heat up
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Module heating factor
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The input voltage is too large or the module is damaged
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Module working temperature
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-40℃~+75℃, industrial grade
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Module features
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Output power LED indication, output 5V linear power
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Scope of application
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Load cell, data acquisition front end, etc.
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Installation Instructions
Precautions for using the module
(1) The power supply of the module is a dual power supply, and the voltage cannot exceed ±15V(AD620) / ±6V(AD623). (2) Since the module is a high-precision device, in order to avoid unnecessary interference, it is recommended to use a linear power supply. (3) For the output signal, it is recommended to use a good wire to input and output the signal, and use an oscilloscope to observe the effect. Poor contact or inferior wire may cause signal attenuation or excessive noise.
vFrequently Asked Questions
Q: How to adjust zero when the module is single-ended input? A: The module defaults to single-ended input. After IN+ is grounded with a resistor, the offset can be adjusted to zero, or the input signal can be adjusted to zero by adjusting R6. Q: The module is single-ended by default. What should I do if I need to input a differential signal? A: When you need to input a differential signal, you first need to disconnect SB5 with a soldering iron, and then use IN+ and IN- to input. Q: Can't program control gain after switching the jumper cap? A: The module needs to be connected to SB2 with solder after switching the jumper cap, so that the digital potentiometer can be fully connected to the circuit to realize the programmable gain.
Application Suggestion
1. This module is suitable for the amplification of signals above one hundred microvolts. In addition, it should be noted that although the maximum amplification factor given in the official manual is 1000 times, this value may not be achieved in actual use. Different frequencies and sizes The amplification effect of the input signal may be different. The actual amplification factor is affected by the gain bandwidth product and the power supply voltage, that is, the maximum output of the operational amplifier does not exceed the power supply voltage. 2. The gain bandwidth product of the amplifier (designated as GBWP, GBW, GBP or GB) is the product of the amplifier bandwidth and the gain of the bandwidth. It is a parameter used to simply measure the performance of the amplifier. When the frequency is large enough, the gain bandwidth product is A constant. For example, the gain bandwidth product of AD623 is 800KHz, which means that when the frequency is 800Khz, the gain of the device drops to unity gain, that is, A=1 at this time. At the same time, it shows that this amplifier can work up to 800KHzZ without distorting the input signal. Since the product of gain and frequency is determined, when the same device needs to get 10 times gain, it can only work at a frequency of 80kHz. 3. In actual use, AD623 is better than AD620. First, AD623 can be powered by a single power supply, which is a rail-to-rail op amp, but the power supply range of AD623 (±6V@max) is smaller than AD620 (±18V@max) Many, so AD623 is more suitable for integration in low-power and low-voltage applications. Secondly, the internal bias of AD623 is indeed much smaller than that of AD620. When we actually debug the module, we found that AD623 basically does not need to adjust the bias, and the AC signal is basically symmetrical with respect to the zero point. However, AD620 needs to adjust a special bias circuit. The DC component is eliminated, and the effect of zero-point symmetry is achieved. Finally, the bandwidth of AD623 and AD620 are different, and the bandwidth of AD620 is slightly wider than that of AD623.
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