AD620 - Instrumentation Amplifier

The AD620 is a low cost, high accuracy instrumentation amplifier that requires only one external resistor to set gains of 1 to 10,000. Furthermore, the AD620 features 8-lead SOIC and DIP packaging that is smaller than discrete designs and offers lower power (only 1.3 mA max supply current), making it a good fit for battery powered, portable (or remote) applications.

The AD620, with its high accuracy of 40 ppm maximum nonlinearity, low offset voltage of 50 µV max, and offset drift of 0.6 µV/°C max, is ideal for use in precision data acquisition systems, such as weigh scales and transducer interfaces. Furthermore, the low noise, low input bias current, and low power of the AD620 make it well suited for medical applications such as ECG and non-invasive blood pressure monitors.

The low input bias current of 1.0 nA max is made possible with the use of Superϐeta processing in the input stage. The AD620 works well as a preamplifier due to its low input voltage noise of 9 nV/√Hz at 1 kHz, 0.28 μV p-p in the 0.1 Hz to 10 Hz band, and 0.1 pA/√Hz input current noise. Also, the AD620 is well suited for multiplexed applications with its settling time of 15 μs to 0.01%, and its cost is low enough to enable designs with one in-amp per channel.

FEATURES AND BENEFITS

EASY TO USE

Gain Set with One External Resistor (Gain Range 1 to 10,000)

Wide Power Supply Range (±2.3 V to ±18 V)

Higher Performance than Three

Op Amp IA Designs

Available in 8-Lead DIP and SOIC Packaging

Low Power, 1.3 mA max Supply

LOW NOISE

9 nV/√Hz, @ 1 kHz, Input Voltage Noise

0.28 µV p-p Noise (0.1 Hz to 10 Hz)

EXCELLENT DC PERFORMANCE (B GRADE)

50 µV max, Input Offset Voltage

0.6 µV/°C max, Input Offset Drift

1.0 nA max, Input Bias Current

100 dB min Common-Mode 

Rejection Ratio (G = 10)

EXCELLENT AC SPECIFICATIONS
             

120 kHz Bandwidth (G = 100)

15 µs Settling Time to 0.01%