Analog Devices AD620, C1599c07 specifications Connection Diagram, Product Description

a Low Cost, Low Power

Instrumentation Amplifier

AD620

FEATURES EASY TO USE

Gain Set with One External Resistor (Gain Range 1 to 1000)

Wide Power Supply Range (62.3 V to 618 V)

Higher Performance than Three Op Amp IA Designs Available in 8-Lead DIP and SOIC Packaging

Low Power, 1.3 mA max Supply Current

EXCELLENT DC PERFORMANCE (“B GRADE”) 50 mV max, Input Offset Voltage

0.6mV/8C max, Input Offset Drift

1.0nA max, Input Bias Current

100 dB min Common-Mode Rejection Ratio (G = 10)

LOW NOISE

9nV/√Hz, @ 1 kHz, Input Voltage Noise 0.28 mV p-p Noise (0.1 Hz to 10 Hz)

CONNECTION DIAGRAM

8-Lead Plastic Mini-DIP (N), Cerdip (Q)

and SOIC (R) Packages

RG	1		8	RG
–IN	2		7	+VS
+IN	3		6	OUTPUT
–V	4	AD620	5	REF
S

TOP VIEW

1000. 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.

EXCELLENT AC SPECIFICATIONS 120 kHz Bandwidth (G = 100)

15 ms Settling Time to 0.01%

APPLICATIONS

Weigh Scales

ECG and Medical Instrumentation

Transducer Interface

Data Acquisition Systems

Industrial Process Controls

Battery Powered and Portable Equipment

PRODUCT DESCRIPTION

The AD620 is a low cost, high accuracy instrumentation ampli- fier that requires only one external resistor to set gains of 1 to

	30,000
SCALE	25,000			3 OP-AMP
				IN-AMP
				(3 OP-07s)
OF FULL
	20,000
PPM	15,000
		AD620A
ERROR,
	10,000	RG
TOTAL	5,000
	0
	0	5	10	15	20
			SUPPLY CURRENT – mA

Figure 1. Three Op Amp IA Designs vs. AD620

REV. E

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The AD620, with its high accuracy of 40 ppm maximum nonlinearity, low offset voltage of 50 μV max and offset drift of

0.6μV/°C max, is ideal for use in precision data acquisition systems, such as weigh scales and transducer interfaces. Fur- thermore, the low noise, low input bias current, and low power of the AD620 make it well suited for medical applications such as ECG and noninvasive 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,

0.1pA/√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.

10,000
	1,000
VOLTAGE NOISE – 10Hz) –mV p-p			TYPICAL STANDARD
			BIPOLAR INPUT
	100		IN-AMP
		G = 100
	10
RTI (0.1					AD620 SUPERbETA
	1				BIPOLAR INPUT
					IN-AMP
	0.1
	1k	10k	100k	1M	10M	100M
			SOURCE RESISTANCE –V

Figure 2. Total Voltage Noise vs. Source Resistance

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Fax: 781/326-8703	© Analog Devices, Inc., 1999