ANALOG DEVICES AD8229-KGD Service Manual

1 nV/√Hz Low Noise 210°C

AD8229-KGD

10107-003

–IN

+IN

OUT

REF –V

AD8229-KGD

100

–20

–40

–60

–80

–100

OSI

(µV)

–55 –35 –15 5 25 45 65 85 105 125 145 165 185 205 225

TEMPERATURE (°C)

09412-016

Known Good Die

FEATURES

Designed for 210°C operation Low noise

1 nV/√Hz input noise 45 nV/√Hz output noise

High CMRR

126 dB CMRR (minimum), G = 100 80 dB CMRR (minimum) to 5 kHz, G = 1

Excellent ac specifications

15 MHz bandwidth (G = 1)

1.2 MHz bandwidth (G = 100) 22 V/µs slew rate THD: 130 dB (1 kHz, G = 1)

Versatile

±4 V to ±17 V dual supply Gain set with single resistor (G = 1 to 1000) Temperature range: −40°C to +210°C

Known good die (KGD): these die are fully guaranteed to

data sheet specifications

APPLICATIONS

Down-hole instrumentation Harsh environment data acquisition Exhaust gas measurements Vibration analysis

GENERAL DESCRIPTION

The AD8229-KGD is an ultralow noise instrumentation amplifier designed for measuring small signals in the presence of large common-mode voltages and high temperatures.

The AD8229-KGD has been designed for high temperature operation. The process is dielectrically isolated to avoid leakage currents at high temperatures. The design architecture was chosen to compensate for the low V

The AD8229-KGD excels at distinguishing tiny signals. It delivers industry leading 1 nV/√Hz input noise performance. The high CMRR of the AD8229-KGD prevents unwanted signals from corrupting the acquisition. The CMRR increases as the gain increases, offering high rejection when it is most needed.

The AD8229-KGD is one of the fastest instrumentation amplifiers available. Its current feedback architecture provides bandwidth that is quite high, even at high gains, for example, 1.2 MHz at G = 100. With the high bandwidth comes excellent distortion performance, allowing use in demanding applications such as vibration analysis.

Rev. 0

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voltages at high temperatures.

Instrumentation Amplifier

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

Gain is set from 1 to 1000 with a single resistor. A reference pin allows the user to offset the output voltage. This feature is useful when interfacing with analog-to-digital converters.

Additional application and technical information can be found in the AD8229 standard product data sheet.

Figure 2. Typical Input Offset vs. Temperature (G = 100)

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