AD620 (Instrumentation Amplifier IC)

Description

🎛️ AD620 – Instrumentation Amplifier IC

Precision, Low-Power, Low-Noise Differential Amplifier

📌 General Description

The AD620 is a low-cost, high-accuracy instrumentation amplifier that requires only one external resistor to set its gain. It features high input impedance, low input offset voltage, low bias current, and low power consumption. It is ideal for precision data acquisition and medical instrumentation systems.

⚙️ Key Specifications

🧪 Key Features

• Low power and low noise
• Easy gain setting with single resistor (external)
• High CMRR for excellent noise rejection
• Operates with dual or single supply
• Ideal for use with bridge sensors and transducers
• Rail-to-rail output capability (when powered appropriately)

🛠️ Typical Applications

• Medical instrumentation (e.g., ECG, EEG, EMG)
• Pressure sensors and load cells
• Thermocouple amplification
• Data acquisition systems
• Industrial process control
• Transducer interfacing

🔌 Pinout (8-Pin DIP/SOIC)

        +---------+
  RG   | 1     8 | V+
  -IN  | 2     7 | Output
  +IN  | 3     6 | Ref
  V−   | 4     5 | RG
        +---------+

📐 Gain Setting Example

To set gain using a resistor RG:

G=1+(49.4kΩRG)G = 1 + \left(\frac{49.4k\Omega}{R_G}\right)

🧯 Advantages

• High precision and linearity
• Very low input offset voltage and drift
• Ideal for low-signal amplification (microvolt level)
• Wide operating voltage range
• Industry standard; widely supported

⚠️ Limitations

• Limited bandwidth at high gain
• Output swing limited by supply voltage (not fully rail-to-rail)
• Slower compared to high-speed op-amps

📦 Common Part Numbers

• AD620AN – DIP-8