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AD623ARZ-R7 application issue caused the voltage on pin 6 is too high

Category: Hardware
Product Number: AD623ARZ-R7
Software Version: NA

That’s function test failure and found the IC output abnormal more than 8mV on pin 6, idea value zero output voltage, the defective IC pin 6 output a more than 8mV voltage cause ear circuit function failed at 4.13mA( GE spec 4.05 mA ± 0.05 mA), see attachment

Here is tracking which material DC test pass, the problem from new DC 202029,  so please confirm with IC manufacturer  what any change since DC 201939? What root cause,

Date Code

Total

FCT test status

201131

371

PASS

201308

248

PASS

201408

130

PASS

201423

97

PASS

201511

99

PASS

201541

151

PASS

201618

2

PASS

201623

2

PASS

201939

368

PASS

202213(shold be 202150)

32

Failed ,100%.

202029

16

Failed ,100%.

XLSX

Parents
  • We have discussed the problem and we think that the AD623 is operated out of specifications. The datasheet specifies minimum output voltage of 200mV, so you can't expect normal operation if it is not met. In your case the amplifier's output is saturated and it does not work as a normal inamp. Different chip markings can mean different behaviour in such state, so it does not mean that the IC is defective. To solve the problem you can try to find another inamp with lower specified output voltage. If you want to keep the AD623, then you can apply negative supply voltage at pin 4. Alternatively, you can shift the output safely above 200mV by applying a bias voltage to the REF pin and configuring the AD694 input to use the difference between the output voltage and REF voltage of the AD623.
    We hope we could help you in time.

Reply
  • We have discussed the problem and we think that the AD623 is operated out of specifications. The datasheet specifies minimum output voltage of 200mV, so you can't expect normal operation if it is not met. In your case the amplifier's output is saturated and it does not work as a normal inamp. Different chip markings can mean different behaviour in such state, so it does not mean that the IC is defective. To solve the problem you can try to find another inamp with lower specified output voltage. If you want to keep the AD623, then you can apply negative supply voltage at pin 4. Alternatively, you can shift the output safely above 200mV by applying a bias voltage to the REF pin and configuring the AD694 input to use the difference between the output voltage and REF voltage of the AD623.
    We hope we could help you in time.

Children
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